Chapter 5: Infection Part 1 Flashcards
What are the safest classes of antibiotics to use in pregnancy?
Penicillins, erythromycin and Cephalosporins (cefalexin (1st gen cefalexin, 2nd gen ceftriaxone, 1st gen cefadroxil)- all but Cefopime a 4th generation cephalosporin
What antibiotic treatment is indicated for septicaemia (community)?
Community-Acquired Septicaemia:
Broad-spectrum antipseudomonal penicillin: (e.g. piperacillin with tazobactam, ticarcillin with clavulanic acid) or a broad-spectrum cephalosporin (e.g. cefuroxime).
If MRSA is suspected: Add vancomycin (or teicoplanin).
If anaerobic infection is suspected: Add metronidazole to broad-spectrum cephalosporin.
If other resistant organisms are suspected: Use a more broad-spectrum beta-lactam antibacterial (e.g. meropenem).
What antibiotic treatment is indicated for septicaemia (hospital acquired)?
Hospital-Acquired Septicaemia:
Broad-spectrum antipseudomonal beta-lactam: antibacterial (e.g. piperacillin with tazobactam, ticarcillin with clavulanic acid, ceftazidime, imipenem with cilastatin, or meropenem).
If MRSA is suspected: Add vancomycin (or teicoplanin).
If anaerobic infection is suspected: Add metronidazole to broad-spectrum cephalosporin.
How to manage Meningococcal Septicaemia (community or hospital acquired?)
also what to do after initial treatment is completed and why?
Meningococcal Septicaemia:
Suspected Meningococcal Disease: Benzylpenicillin (before Urgent transfer to the hospital)
Penicillin Allergy: Cefotaxime
Immediate Hypersensitivity to penicilins and cephalosporins: Chloramphenicol
After treatment
To Eliminate Nasopharyngeal Carriage: Ciprofloxacin, Rifampicin, or Ceftriaxone
Ceftriaxone
What antibiotic Is very good against anaerobic bacteria so usually infections of the colon?
Metronidazole - V high anaerobic activity, narrow spectrum
Very high anaerobic activity: Effective against bacteria in low-oxygen environments.
Narrow spectrum: Targets anaerobes specifically, unlike broad-spectrum antibiotics.
Used for:
Gut infections (e.g., H. pylori, Crohn’s disease)
Bacterial vaginosis
Leg ulcers or other anaerobic infections like abscesses.
How is bacterial meningitis empirically treated?
Pre-Hospital?
In-Hospital?
when to avoid dexamethasone?
Unknown Aetiology?
Treatment Duration?
In a nut shell:
1) BENZYPENICILLIN- can be given before transfer to hospital (emergency situation in community)
2) If penicillin allergy- CEFOTAXIME (a cephalosporin)
If hypersensitivity to penicillin & cephalosporins: CHLORAMPHENICOL
4) Can consider addition of Dexamethasone
5) Consider Vancomycin if multiple use of antibiotics in previous 3 months
expand:
Meningitis: Initial Empirical Therapy
Pre-Hospital
Urgent transfer: Immediate transfer to hospital is critical.
Suspected Meningococcal Disease (non-blanching rash or septicaemia): Give Benzylpenicillin Sodium before transfer if it doesn’t delay transport.
Suspected Bacterial Meningitis without non-blanching rash: Give Benzylpenicillin Sodium if transfer is delayed.
Alternative treatments for penicillin allergy:
Cefotaxime if penicillin allergy.
Chloramphenicol if hypersensitivity to both penicillins and cephalosporins.
In-Hospital
Adjunctive Dexamethasone:
For suspected pneumococcal meningitis, start before or with the first antibiotic dose. but no later than 12 hours after starting antibacterial
Avoid if: septic shock, meningococcal septicaemia, immunocompromised, or post-surgery meningitis.
Unknown Aetiology:
Adults & children (3 months to 59 years): Cefotaxime or Ceftriaxone (consider vancomycin if recent multiple antibiotic use or foreign travel).
Adults ≥60 years: Cefotaxime or Ceftriaxone + Amoxicillin (consider vancomycin under the same conditions).
Treatment Duration: Minimum 10 days for all.
What is the treatment for meningococcal meningitis?
Benzylpenicillin or cefotaxime
2nd line: Chloramphenicol For 7 days
What is the treatment for pneumococcal meningitis?
duration of treatment?
First-line treatment: Cefotaxime or Ceftriaxone.
Adjunctive dexamethasone: Consider starting before or with the first dose of antibacterial, but no later than 12 hours after starting. Note: may reduce vancomycin penetration into cerebrospinal fluid.
If organism is known to be penicillin-sensitive: Switch to benzylpenicillin sodium.
If highly penicillin- and cephalosporin-resistant: Add vancomycin and, if necessary, rifampicin.
Duration of antibacterial treatment: 14 days.
if penicilin allergic give vancomycin with moxifloxacin or meropenem
What is the treatment for meningitis caused by haemophilus influenza?
Duratoion of treatment?
Haemophilus Influenzae Meningitis Treatment
First-line treatment: Cefotaxime or Ceftriaxone.
Adjunctive dexamethasone: Consider starting before or with the first dose of antibacterial, but no later than 12 hours after starting treatment.
Duration of antibacterial treatment: 10 days.
H. influenzae type b (before discharge): Give rifampicin for 4 days to:
Children under 10 years.
Household contacts with vulnerable individuals.
If penicillin or cephalosporin allergy or resistance: Use chloramphenicol.
Consider adding dexamethasone, preferably starting before or with first dose of antibacterial, but no later than 12 hours after starting antibacterial.
What is the treatment for meningitis caused by Listeria?
Treatment duration?
first line: Amoxicillin (or ampicillin) + gentamicin
Suggested duration of treatment 21 days.
Consider stopping gentamicin after 7 days.
second line: If history of immediate hypersensitivity reaction to penicillin, co-trimoxazole only alone
Suggested duration of treatment 21 days.
What antibiotics are used in endocarditis (infection of the heart) initial blind therapy?
Native valve endocarditis: Amoxicillin (or ampicillin).
Consider adding: low-dose gentamicin.
If penicillin-allergic, MRSA suspected, or severe sepsis: Use vancomycin + low-dose gentamicin.
If severe sepsis with risk factors for Gram-negative infection: Use vancomycin + meropenem.
Prosthetic valve endocarditis: Use vancomycin + rifampicin + low-dose gentamicin.
Note: Gentamicin dosing targets: trough <1, peak 3-5.
Note: Gentamicin dosing targets: trough <1, peak 3-5.
approach for Staphylococcal Endocarditis:?
Duration of treatment for each scenario?
Staphylococcal Endocarditis (Native Valve)
First-line treatment: Flucloxacillin.
Duration: 4 weeks (extend to 6 weeks if secondary lung abscess or osteomyelitis is present).
If penicillin-allergic or MRSA suspected: Use vancomycin + rifampicin.
Duration: Same as above—4 weeks, extend to 6 weeks if needed.
Staphylococcal Endocarditis (Prosthetic Valve)
First-line treatment: Flucloxacillin + rifampicin + low-dose gentamicin.
Duration: At least 6 weeks. Review gentamicin at 2 weeks (specialist advice required if continuation is necessary).
If penicillin-allergic or MRSA suspected: Use vancomycin + rifampicin + low-dose gentamicin.
Duration: Same as above—6 weeks, review gentamicin at 2 weeks.
Note: Gentamicin dosing targets: trough <1, peak 3-5.
Note: Gentamicin dosing targets: trough <1, peak 3-5.
approach for Enterococcal Endocarditis:
First-line: Amoxicillin (or ampicillin) + low-dose gentamicin (or benzylpenicillin sodium + low-dose gentamicin)
Duration: 4-6 weeks (6 weeks for prosthetic valves)
Review gentamicin: at 2 weeks, specialist advice if needed beyond 2 weeks
Penicillin-allergic or resistant: Vancomycin (or teicoplanin) + low-dose gentamicin
Gentamicin-resistant: Amoxicillin (or ampicillin) + streptomycin (if susceptible)
Duration: At least 6 weeks.
approach for Streptococcal Endocarditis:?
Streptococcal Endocarditis (Fully Sensitive)
First-line treatment: Benzylpenicillin sodium.
Duration: 4–6 weeks (Use 6 weeks for prosthetic valve endocarditis).
If penicillin-allergic or resistant: Use vancomycin (or teicoplanin) + low-dose gentamicin.
Duration: 4–6 weeks (Stop gentamicin after 2 weeks).
Endocarditis: Less-Sensitive Streptococci
First-line treatment: Benzylpenicillin sodium + low-dose gentamicin.
Duration: 4–6 weeks (Use 6 weeks for prosthetic valve endocarditis).
Review gentamicin: Stop after 2 weeks if microorganisms are moderately sensitive to penicillin. Seek specialist advice if continuation is necessary beyond 2 weeks.
If penicillin-allergic or highly penicillin-resistant: Use vancomycin (or teicoplanin) + low-dose gentamicin.
Duration: Same as above—4–6 weeks, review gentamicin at 2 weeks.
Note: Gentamicin dosing targets: trough <1, peak 3-5.
Note: Gentamicin dosing targets: trough <1, peak 3-5.
approach for Enterococcal Endocarditis?
Duration of treatment?
First-line treatment:
Amoxicillin (or ampicillin) + low-dose gentamicin or
Benzylpenicillin sodium + low-dose gentamicin.
Duration: 4–6 weeks (Use 6 weeks for prosthetic valve endocarditis).
Review gentamicin at 2 weeks—seek specialist advice if continuation is necessary beyond 2 weeks.
If penicillin-allergic or penicillin-resistant: Use vancomycin (or teicoplanin) + low-dose gentamicin.
Duration: Same as above—4–6 weeks (6 weeks for prosthetic valve endocarditis).
If gentamicin-resistant: Use amoxicillin (or ampicillin) and add streptomycin (if susceptible) for 2 weeks.
Duration: At least 6 weeks.
Note: Gentamicin dosing targets: trough <1, peak 3-5.
Note: Gentamicin dosing targets: trough <1, peak 3-5.
approach for Endocarditis caused by Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella species (‘HACEK’ micro-organisms)?
(Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella)
First-line treatment: Amoxicillin (or ampicillin) + low-dose gentamicin.
Duration: 4 weeks (Use 6 weeks for prosthetic valve endocarditis).
Stop gentamicin: After 2 weeks.
If amoxicillin-resistant: Use Ceftriaxone (or cefotaxime) + low-dose gentamicin.
Duration: Same as above—4 weeks (6 weeks for prosthetic valve endocarditis).
Note: Gentamicin dosing targets: trough <1, peak 3-5.
Note: Gentamicin dosing targets: trough <1, peak 3-5.
What antibiotic is indicated for gastro-enteritis?
This is usually self-limiting and an antibiotic not indicated
What is the antibiotic indicated for C. diff?
Here’s a condensed version for your flashcard:
C. difficile Infection Treatment:
First Episode:
- Oral 1st line: Vancomycin
- Oral 2nd line: Fidaxomicin
- If ineffective: Seek specialist advice
Further Episodes:
- Relapse (≤12 weeks): Fidaxomicin
- Recurrence (>12 weeks): Vancomycin or Fidaxomicin
Life-Threatening Infection:
- Treatment: Oral Vancomycin + IV Metronidazole (specialist care)
Which antibiotics are commonly used for GU infections?
GU Infections: Commonly Used Antibiotics
1. Urinary Tract Infections (UTIs)
First-line:
Nitrofurantoin (Avoid in renal impairment)
Trimethoprim (Not used in pregnancy unless resistant)
Fosfomycin (Single dose for uncomplicated UTIs)
Alternatives:
Cefalexin
Amoxicillin (if sensitive)
Ciprofloxacin (reserved for complicated cases)
2. Pyelonephritis
First-line:
Ciprofloxacin
Co-amoxiclav (Amoxicillin/clavulanate)
Alternatives:
Cefalexin
Trimethoprim (if susceptible)
3. Sexually Transmitted Infections (STIs)
Chlamydia:
Azithromycin (Single-dose) or Doxycycline (7-day course)
Gonorrhea:
Ceftriaxone (IM) with Azithromycin (Due to resistance)
Pelvic Inflammatory Disease (PID):
Ceftriaxone (IM) + Doxycycline + Metronidazole
4. Prostatitis
First-line:
Ciprofloxacin
Trimethoprim
Doxycycline
What class of AB’s is Amikacin? When is amikacin usually indicated?
Class: Aminoglycoside antibiotic.
Indications:
Serious Gram-negative infections (e.g., Pseudomonas aeruginosa).
Used for sepsis, pneumonia, intra-abdominal infections, and UTIs.
Often reserved for infections resistant to other aminoglycosides (gentamicin) or multidrug-resistant organisms.
Common in hospital-acquired infections.
Usage: Typically combined with other antibiotics for broad coverage.
An aminoglycoside usually indicated for gentamicin resistant infections as amikacin is more stable than gentamicin to enzyme inactivation.
What is the target One hour peak concentration of gentamicin? (multiple daily dosing)
5 - 10 mg/L (3-5mg/L For multiple daily dose regimen in endocarditis)
What is the target pre-dose trough concentration of gentamicin? (multiple daily dosing)
under 2 mg/L (<1mg/L For multiple daily dose regimen in endocarditis)
What is the target One hour peak conc of gentamicin in treatment of ENDOCARDITIS? and target trough level?
Peak: 3 - 5 mg/L Trough: <1mg/L
Which aminoglycoside is too toxic to be administered parenterally, therefore is taken by mouth?
NEOMYCIN - used for bowel sterilisation before surgery as its so strong it will wipe the bowel clean of bacteria
Etrapenem, Imipenem and Meropenem are all examples of what kind of antibiotics?
The carbapenems. These are beta-lactam antibacterials
NB: imipenem is administered with cilastatin which is a specific enzyme inhibitor that stops it being renally metabolised
Which two cephalosporins are suitable for infections of the CNS?
Cefotaxime + Ceftriaxone (TAX AND TRAX) (Hint: these are the two we see used in meningitis, a CNS infection!)
Talk me through treatment of UTI’s in pregnancy?
Here’s the information condensed into a flashcard format:
UTI Treatment in Pregnancy:
- Nitrofurantoin: Safe during pregnancy but avoid at term (risk of neonatal hemolysis).
- Trimethoprim: Avoid in the first trimester (teratogenic risk as a folate antagonist).
- Cefalexin: Safe for use throughout pregnancy.
- Cranberry products: Not recommended (no evidence to support use).
term pregnancy is any pregnancy from 37 weeks and beyond until delivery
This summary aligns with current NICE guidelines for treating UTIs during pregnancy【15†source】【16†source】【17†source】. : term pregnancy is any pregnancy from 37 weeks and beyond until delivery
What classes, other than penicillins, do we have to be wary of with penicillin allergic patients?
For penicillin-allergic patients, the main classes of antibiotics to be cautious with are cephalosporins and carbapenems due to their beta-lactam structure, which can potentially trigger cross-reactivity. The cross-sensitivity between penicillins and first-generation cephalosporins is reported to be higher (about 10%), while it is lower (around 2-3%) for third-generation cephalosporins like ceftriaxone【24†source】【25†source】.
Here’s a condensed version for your flashcard:
Penicillin Allergy:
- Cephalosporins (e.g., cefalexin, ceftriaxone): 0.5-10% cross-sensitivity
- Carbapenems: Potential cross-reactivity, though lower than cephalosporins
Other Considerations:
- Monobactams (e.g., aztreonam): Generally safe in penicillin-allergic patients.
What is Co-trimoxazole? What is it used for?
Co-trimoxazole Use:
- Contains: Sulfamethoxazole and Trimethoprim
- Limited Use Due to Resistance
- Indicated for:
- Pneumocystis jirovecii (P. carinii) pneumonia
- Toxoplasmosis
- Nocardiasis
- Restricted Use in children:
- Only in bronchitis exacerbations, UTIs, and otitis media in children when culture and sensitivities are evident.
- Important: Only use when there is strong evidence to justify the combination therapy over a single agent due to increasing resistance
【32†source】【33†source】.
What antibiotics require reporting on blood disorders/ rash?
Co-trimoxazole (contains trimethoprim and sulfamethoxazole)- discontinue immediately if: signs of a blood disorder such as anaemia, thrombocytopenia or rash: stevens johnsons syndrome, photosensitivity
Trimethoprim: Blood disorders: fever, sore throat, ulcers, bruising, bleeds
Penicillamine: not really an anti-bacterial: used as a disease-modifying anti-rheumatic drug Same as above: fever, sore throat, ulcers, bruising
Amoxicillin: Report if rash (especially in glandular fever) or blood disorders (e.g., eosinophilia, anemia) develop.
Vancomycin: Monitor for neutropenia and other blood dyscrasias.
Linezolid: Requires reporting for thrombocytopenia or other blood disorders during prolonged use.
What do you see fusidic acid commonly used for?
Staphylococcal infection of the SKIN e.g. impetigo & also EYES comes as tablet, cream, eye drops
Fusidic Acid
What is it?: Fusidic acid is a narrow-spectrum antibacterial that is primarily used topically.
Indications:
Non-bullous impetigo (first-choice topical antibiotic).
Secondary bacterial infections of eczema or other localized skin infections caused by Staphylococcus aureus.
Conjunctivitis (topical fusidic acid in the form of eye drops).
Usage Instructions:
Applied 2–3 times daily for 5-7 days.
Avoid prolonged use due to risk of antimicrobial resistance.
Important Considerations:
Should not be used extensively or recurrently to prevent the development of resistance.
Only use for localized infections and when systemic infection is not suspected.
not check from here but i presume correct
What happens if a patient on clindamycin develops diarrhoea?
Clindamycin and Diarrhoea Management
Diarrhoea on clindamycin?: May indicate C. difficile infection.
First step: Stop clindamycin immediately.
Test: Send stool sample to test for C. difficile toxin.
Treatment: If confirmed, treat with oral vancomycin or fidaxomicin. Use metronidazole if severe or other options unavailable.
Antibiotic associated colitis with clindamycin can be fatal- discontinue immediately + start vancomycin if c.diff is confimed
What antibiotic has been associated with Myopathy/ Muscle effects?
What to monitor?
Antibiotics and Myopathy/Muscle Effects
Daptomycin: Can cause myopathy and rhabdomyolysis. Monitor CK levels.
Action: Stop the antibiotic and check CK if muscle pain or weakness develops.
additional info for muscle effects other than myophathy:
Fluoroquinolones: Associated with tendonitis (not myopathy) and tendon rupture (especially Achilles). just a muscle effect not myopathy
CK levels means: creatine kinase (CK). the main one is Daptomycin
Which antibiotics can cause cholestatic jaundice?
Flucloxacillin ( even upto 2 months after): Can also cause cholestatic hepatitis and jaundice, often presenting weeks after stopping the medication. this is the main one
Others:
Co-amoxiclav: Commonly associated with cholestatic jaundice and liver dysfunction, particularly in older adults or after prolonged use.
Nitrofurantoin: May cause cholestatic jaundice with prolonged use, especially in elderly patients. Liver function should be monitored.
Erythromycin and other macrolides: These are associated with cholestasis and liver toxicity.
Be careful in liver patients and regularly monitor liver function
What is the important safety information associated with Flucloxacillin?
Hepatic disorders: Cholestatic Jaundice and HEPATITIS have been reported in patients even up to 2 months after the drug has been stopped.
to expand:
Hypersensitivity: Flucloxacillin can cause severe allergic reactions, including anaphylaxis, particularly in patients with a history of penicillin allergy.
Cholestatic Jaundice and Hepatitis:
Cholestatic jaundice or hepatitis may occur during treatment or up to 2 months after stopping flucloxacillin.
Risk is higher in older adults and after prolonged use (greater than 2 weeks).
Renal Impairment: Dose adjustments are required in patients with severe renal impairment (eGFR less than 10 mL/min) to avoid toxicity.
Other cautions:
Use with caution in people with hepatic dysfunction or serious underlying disease.
Should not be prescribed to people with a history of flucloxacillin-associated jaundice or hepatic dysfunction.
Use flucloxacillin with caution in patients with liver impairment!!
A few antibiotics have been associated with visual problems. Can you think of any?
LINEZOLID- optic nephropathy
QUINOLONES (Ciprfloxacin, Levofloxacin)- Fluoroquinolones Can cause blurred vision, photophobia, and in rare cases, retinal detachment.
Ethambutol (used for TB)- ocular toxicity
Rifampicin- colours tears/ contacts red
Rifabutin- Uveitis (eye inflammation)
Doxycycline: May lead to visual disturbances and photosensitivity.
What two things need to be looked out for with Linezolid treatment?
Optic neuropathy (visual problems)- report any visual disturbance IMMEDIATELY
Blood disorders:Aneamia, thrombocytopenia
FBC monitored WEEKLY, monitor especially for treatment of 10-14 days or more
What are the three very important safety warnings with QUINOLONES (ciprofloxacin, levofloxacin)?
Fluoroquinolones: Important Safety Information
Convulsions: May induce seizures, especially when taken with NSAIDs. Caution is advised for patients with epilepsy or those taking theophylline, as both increase the risk of convulsions.
Tendon Damage: Can cause tendonitis or tendon rupture, especially in the Achilles tendon. The risk is increased when combined with corticosteroids.
QT Prolongation: Fluoroquinolones can prolong the QT interval, increasing the risk of heart arrhythmias. Caution is needed in patients with existing risk factors like electrolyte imbalances.
MHRA Warning: Fluoroquinolones have been associated with rare but potentially irreversible side effects, affecting the musculoskeletal and nervous systems, and should not be used for non-severe infections unless other treatments are inappropriate.
When should patients discontinue treatment with Quinolones?
When to Discontinue Fluoroquinolones
Stop immediately if:
Tendon pain or swelling (signs of tendonitis or rupture).
Muscle pain, weakness, or joint pain and swelling.
Peripheral neuropathy (numbness, tingling, burning sensations)
.
Central nervous system effects (e.g., depression, psychosis, or seizures).
Seek immediate medical advice if these symptoms develop to avoid long-term or irreversible side effects.
WHAT ANTIOBIOTICS CAN CAUSE QT PROLONGATION??!
Macrolides:
Erythromycin and Clarithromycin are commonly associated with QT interval prolongation. They can increase the risk of ventricular arrhythmias like torsades de pointes, particularly in patients with underlying heart conditions or electrolyte imbalances (e.g., low potassium).
Fluoroquinolones:
Ciprofloxacin,Levofloxacin and especially Moxifloxacin can prolong the QT interval and lead to arrhythmias, especially in patients also taking other QT-prolonging drugs.
Antifungal Azoles:
While not antibiotics, Fluconazole is often grouped with antimicrobial agents that prolong QT intervals.
Other Considerations:
Caution is advised when combining any of these antibiotics with other medications known to prolong QT or in patients with pre-existing heart conditions.
Linezolid is an antibacterial used in pneumonia. It also had Monoamine oxidase inhibition activity (part of MAOI family). What should patients be advised to avoid?
Avoid consuming large amounts of Tyramine rich foods (mature cheese, , wine, beer)
Avoid foods high in tyramine:
Aged cheese, smoked meats, soybean, red wine, tap beer.
Avoid serotonergic drugs:
SSRIs, tricyclic antidepressants (to prevent serotonin syndrome).
Remember: Linezolid will still have interactions/ tyramine effects 2 weeks after discontinuation!!
What can happen if VANCOMYCIN is infused too rapidly?
Vancomycin: Rapid Infusion Risks
Red Man Syndrome: Rapid infusion can cause flushing, rash, itching, and redness, particularly of the upper body. This reaction is due to histamine release.
Severe Hypotension and Cardiac Events: Rapid infusion may lead to severe hypotension, shock, or even cardiac arrest.
Wheezing
Pruritis
Pain/ muscle spasm in back
What to do?:
Slow the infusion rate (at least 60 minutes for doses under 1g).
Premedicate with an antihistamine to reduce the risk of reactions.
Flushing of upper body= RED MAN SYNDROME
After how many doses should Vancomycin plasma levels be measured?
Before 3 or 4 doses if renal function is normal (earlier if its impaired!)
expanded:
Vancomycin: Plasma Level Monitoring
Measure trough plasma levels: Before the 3rd or 4th dose to ensure therapeutic levels are reached.
Target trough levels: Between 10–20 mg/L.
Ongoing monitoring: Recheck levels regularly (e.g., twice weekly) if the treatment continues, especially in patients with renal impairment.
Before 3 or 4 doses if renal function is normal (earlier if its impaired!)
What side effects do Vancomycin and Gentamicin both have in common? What drugs should be avoided with these?
Vancomycin and Gentamicin: Common Side Effects
Ototoxicity: Both drugs can cause hearing loss, tinnitus (ringing in the ears), and vertigo due to damage to the auditory nerves.
Nephrotoxicity: Both can lead to kidney damage, especially when used together or with other nephrotoxic drugs.
Drugs to Avoid
Obviously avoid use of vancomycin and gentamicin together!
Other nephrotoxic agents: Such as NSAIDs, diuretics, or other aminoglycosides, CICLOSPORINPlatinum chemotherapy.
Other ototoxic agents: Such as loop diuretics (e.g., furosemide).
Treatment with Vancomycin required Full Blood count monitoring. Why is this?
Risk or neutropenia- monitor neutrophils and platelets
Which antibiotics could cause CHOLESTATIC JAUNDICE (a liver disorder where bile builds up in the blood stream as it gets blocker from being excreted)?
FLUCLOXACILLIN - may even occur up to TWO MONTHS after flucloxacillin stopped, more likely after TWO WEEKS of treatment and older age
Co-fluampicil (contains amoxicillin and flucloxacillin)
Co-amoxiclav:Often associated with cholestatic jaundice and liver dysfunction, particularly after prolonged use or in elderly patients.
Nitrofurantoin - Use these with caution in those with liver dysfunction!!
Erythromycin (Macrolide antibiotics): Known to cause cholestatic liver injury in some cases.
Which antibiotics are commonly used to treat acne??
Antibiotics for Acne Treatment
Oral antibiotics:
Lymecycline and Doxycycline: First-line oral antibiotics for moderate to severe acne. They are typically used alongside topical treatments.
Erythromycin (Macrolide): Used if tetracyclines are not suitable (e.g., during pregnancy).
Topical antibiotics:
Clindamycin and Erythromycin: Usually combined with benzoyl peroxide to reduce resistance.Tetracyclines most common: tetracycline, doxycycline, oxytetracycline, lymecycline (trimethoprim for resistant acne)
Erythromycin (a macrolide) sometimes used
Erythromycin (a macrolide) sometimes used
What conditions can Tetracyclines exacerbate?
Renal Impairment: Tetracyclines can worsen kidney function due to their renal excretion. Caution is advised in patients with pre-existing renal failure.
Hepatic Impairment: Tetracyclines can increase the risk of liver toxicity, especially when combined with other hepatotoxic drugs.
Myasthenia Gravis: Tetracyclines can exacerbate muscle weakness in patients with this condition.
Systemic Lupus Erythematosus (SLE): Tetracyclines may worsen symptoms of lupus.
Which antibiotics can cause photosensitivity?
Tetracyclines: Especially doxycycline and Demeclocycline. tetracycline, which are commonly used for acne and can cause severe sunburn-like reactions.
Fluoroquinolones: Such as ciprofloxacin and levofloxacin, which increase the risk of phototoxic reactions with sun exposure.
Sulfonamides: Includes sulfamethoxazole (part of co-trimoxazole), which can cause photosensitivity, especially in combination therapies.
Other drugs: Griseofulvin (antifungal) and dapsone can also trigger photosensitive reactions.
doxycycline is the main one
Which antibiotics are not recommended in children and adolescences under 18 years old? And why?
Fluoroquinolones: Such as ciprofloxacin and levofloxacin, are generally not recommended in patients under 18 years old due to the risk of tendonitis and tendon rupture.
Tetracyclines: Such as doxycycline and tetracycline, are avoided in children under 12 years old because they can cause permanent tooth discoloration and affect bone growth.
Chloramphenicol: Not used in neonates and infants due to the risk of Gray Baby Syndrome, a serious condition due to underdeveloped liver function.Quinolones: Ciprofloxacin, levofloxacin, moxifloxacin
This is because of the risk of TENDON DAMAGE/ JOINT DISEASE (Aropathy)
Tetracyclines - 12+: dental
What is an important monitoring parameter with Linezolid?
Monitor for Thrombocytopenia: Regular blood counts (especially platelets) should be monitored weekly during linezolid treatment to detect thrombocytopenia (low platelet count).
Optic and Peripheral Neuropathy: Monitor for any signs of vision changes or nerve damage during prolonged treatment (over 28 days).
WEEKLY Full Blood Counts due to risk of blood disorder/ anaemia
C
Which antibiotics may cause a false positive result on urinary GLUCOSE tests- i.e. be careful when testing for diabetes?
Cephalosporins: Can interfere with glucose tests, leading to false positive results when using methods like the Clinitest.
Penicillins: Such as amoxicillin may also cause false positives in certain glucose test methods.
Other antibiotics: Levofloxacin and Ofloxacin (fluoroquinolones) can also interfere with some glucose urine tests.
Which antibiotic is a FOLATE SYNTHESIS INHIBITORS and is therefore teratogenic?
Trimethoprim: Inhibits folate synthesis, which is essential for fetal development. It is teratogenic and should be avoided in pregnancy, particularly during the first trimester because it increases the risk of neural tube defects.
Co-trimoxazole (contains sulfamethoxazole and trimethoprim)
Therefore AVOID in pregnancy- especially first trimester when folate is needed
What frequency of administration is Vancomycin given?
Vancomycin: Frequency of Administration
Intermittent infusion: Typically administered every 12 hours, depending on kidney function and infection severity.
Continuous infusion: In certain cases (e.g., severe infections like endocarditis), a continuous infusion is preferred, with doses adjusted based on creatinine clearance and regular monitoring.
Monitoring: Regular plasma level monitoring is crucial, particularly in cases of continuous infusion.
Teicoplanin: even longer acting: OD dosing after loading dose
Name 2 Glycopeptide antibiotics?
Glycopeptide Antibiotics
Vancomycin: Commonly used for serious infections like MRSA and C. difficile.
Teicoplanin: Another glycopeptide used similarly for Gram-positive bacterial infections, including endocarditis.
Teicoplanin (less nephrotoxic than vancomycin)
What are the target pre-dose TROUGH levels for vancomycin?? (only trough levels are used with Vancomycin)
Target Pre-Dose Trough Levels:
Vancomycin: Target Pre-Dose Trough Levels
Standard infections: 10–15 mg/L.
Severe or deep-seated infections (e.g., MRSA, endocarditis): 15–20 mg/L.
Continuous Infusion: Target range typically 20–25 mg/L.
Monitoring: Regular trough level measurements are critical to avoid toxicity and ensure efficacy, especially in renal impairment cases.
15-20 for endocarditis
First line antibiotic for Cellulitis?
Flucloxacillin (250-500mg QDS)
If penicillin allergic: Alternative in penicillin allergy or flucloxacillin unsuitable:clarithromycin, oralerythromycin(in pregnancy), or oral doxycycline.
Which antibiotics/ antifungals may cause STEVENS JOHNSON SYNDROME (skin rash)?
Antibiotics/Antifungals Associated with Stevens-Johnson Syndrome (SJS)
Sulfonamides: Includes sulfamethoxazole (in co-trimoxazole), which has been widely associated with SJS.
Penicillins: Such as amoxicillin and ampicillin.
Cephalosporins: Includes ceftriaxone and cefixime.
Fluoroquinolones: Such as ciprofloxacin and levofloxacin.
Antifungals: Such as fluconazole and itraconazole.
What are some of the more common side effects experienced with Metronidazole (its quite an unpleasant antibiotic)?
Common Side Effects of Metronidazole
Unpleasant metallic taste: A sharp, metallic taste is very common.
Nausea and vomiting: Often experienced, especially with oral forms.
Dry mouth and loss of appetite.
Gastrointestinal discomfort: Includes stomach cramps and diarrhea.
Dizziness or headaches.
Dark urine: May cause the urine to appear darker.
Disulfiram-like reaction with alcohol: Severe nausea, flushing, and palpitations when taken with alcohol.
What is fusidic acid used for?
Narrow spectrum antibiotic used for STAPHYLOCOCCAL SKIN infections
Used for impetigo (topical)
Fucidin cream Staph eye infections (topical)
Which antibiotic is cautioned in problems to do with: Lungs, Liver, and Neurones
Nitrofurantoin:
Lungs: Can cause pulmonary toxicity and Pulmonary Fibrosis, particularly in long-term use.
Liver: May induce** hepatitis** or** cholestatic jaundice.**
Neurons: Rarely, it can cause peripheral neuropathy, especially in patients with renal impairment or long-term use.
also can cause Vit B/ Folate deficiency
F
Which antifungal medication can cause QT prolongation?
Antifungal Medications That Can Cause QT Prolongation
Fluconazole: Known to cause QT interval prolongation and increase the risk of torsades de pointes (a type of life-threatening arrhythmia).
Itraconazole: Another azole antifungal associated with QT prolongation, particularly when used with other QT-prolonging medications or in patients with pre-existing heart conditions.
Voriconazole: Also carries a risk of QT prolongation, especially in higher doses.
What antibiotics/ antifungals should be stopped if signs of dark urine, vomiting, fatigue, anorexia occur?
This indicated LIVER FAILURE
Discontinue drugs that are hepatotoxic:
Terbinafine
Rifampicin Isoniazid Pyrizinamide (R.I.P liver: TB drugs)
Nitrofurantoin: Can cause liver toxicity leading to dark urine, vomiting, and fatigue. Stop immediately if these symptoms develop.
Itraconazole, Fluconazole and Ketoconazole (no longer available oral)!: Known to cause liver dysfunction, which may present with dark urine, fatigue, and anorexia. Stop treatment and seek medical advice.
Which antifungal is cautioned in patients at a high risk of heart failure?
Antifungal Cautioned in High-Risk Heart Failure
Itraconazole: This antifungal is cautioned in patients at high risk of heart failure due to its potential to cause negative inotropic effects, which can worsen existing heart conditions or lead to heart failure.
Monitoring: Close monitoring of cardiac function is essential when using itraconazole, especially in patients with pre-existing cardiac issues.
More at risk if on negatively ionotropic drug e.g. CCB
What skin condition may Terbinafine (antifungal) exacerbate?
Terbinafine: Skin Condition Exacerbation
Psoriasis: Terbinafine may exacerbate psoriasis in some patients. Close monitoring is advised in individuals with a history of this condition.
Which antifungal can cause renal toxicity?
Antifungal That Can Cause Renal Toxicity
Amphotericin B: Known for its potential to cause renal toxicity, particularly when used in high doses or for prolonged periods. It can lead to acute kidney injury (AKI)and requires close monitoring of renal function.
Can also cause electrolyte disturbance: Hypokaleamia and hypomagneseamia
Which antimalarials are unsuitable in patients with epilepsy/ has a history of epilepsy?
Antimalarials Unsuitable in Epilepsy
Chloroquine: Can lower the seizure threshold, making it unsuitable for patients with a history of epilepsy.
Mefloquine: Should be avoided due to its association with neuropsychiatric effects and increased risk of seizures in patients with epilepsy.
A woman, 4 weeks pregnant, comes and asks you what she can do to avoid malaria when she goes to Bolivia next month. Which antimalarials are ok to use in pregnancy?
Chloroquine and Proguanil: These are considered safe for malaria prevention in pregnancy, especially in early pregnancy as benefit of malaria prophylaxis outweighs any risk
BUT recommend FOLIC ACID 5mg to be taken with proguanil
Doxy - last resort and must complete full course before 15 weeks gestati
What does the antimalarial malarone contain?
Proguanil & Atovaquone
This is fine to use in epilepsy; does not contain chloroquine or mefloquine
What is the most common causative bacteria of a UTI?
Escherichia coli (E. coli): The most common bacterial cause of urinary tract infections (UTIs). E. coli originates from the gastrointestinal tract and is responsible for the majority of both uncomplicated and complicated UTIs.
Lonely frail old linda sat in her smelly flat
Lonely linda= Clindamycin (class of its own) Frail= bones - clindamycin used for osteomyelitis as it concentrates in the bones Smelly= diarrhoea= discontinue immediately
Daktocort cream (containing Miconazole and Hydrocortisone) needs to be stored where?? Why??Where is the ointment stored?
Daktocort CREAM stored in fridge- creams are more water based so more liable to bacterial growth
Ointment on shelf- more stable, less water less bacteria
Similar to chloramphenicol eye drops/ ointment- DROPS in FRIDGE as more water based
ointment on shelf
What drugs are used to treat Bacterial Vaginosis?
Metronidazole vaginal gel
Clindamycin cream
Which antifungal requires an Alert card as it is so Hepato-toxic?
Voriconazole
What two toxicities may Voriconazole cause?
Hepatotoxicity
Phototoxcity- avoid sunlight!
When should a penicillin be discontinued? Describe the affects.
Individuals with a history of anaphylaxis, urticaria, or rash immediately after a penicillin should discontinue and not receive penicillins as these are at risk of immediate hypersensitivity.
The rash would come up straight away, be wide spread, all over body, confluent, raised and itchy (urticaria= hives like rash).
Those with history of a minor rash (non-confluent, localised to one area, non-itchy) that occurred more than 72 hours after starting the penicillin are probably not truly allergic, and if a penicillin is absolutely needed they may receive it.
What antibiotics are commonly seen prescribed for chest infections?
Penicillins- Amoxicillin or Ampicillin
Or if not: A Macrolide - Azithromycin, Clarithromycin or Erythromycin
Co-amoxiclav used for more serious chest infections as it has broader action over the typical bacteria (e.g. H. influenzae)
Co-amoxiclav used for more serious chest infections as it has broader action over the typical bacteria (e.g. H. influenzae)
How is oral thrush managed?
Initially TOPICAL treatment with either Miconazole oromucosal gel or
NYSTATIN oral suspension (use pipette provided, hold in mouth, used after food)
If these don’t work or patient has a dry mouth can use Oral fluconazole capsule
Which anti-epileptic does Meropenem reduce the levels of?
Sodium Valproate
Meropenem Interaction: Sodium Valproate
Effect: Meropenem significantly reduces sodium valproate levels, which can lead to a loss of seizure control. This interaction can result in a drop of valproate levels by up to 100% within 24 hours.
Management: Sodium valproate should not be stopped, but adjunct therapy with levetiracetam is often recommended during meropenem treatment
What is the usual organism (Not atypical) causing Lower respiratory tract infections?
Streptococcus pneumoniae - major cause of pneumonia S. pneumoniae is also one of the major causes of meningitis (pneumonococcal) along with Neisseria meningitidis (meningococcal)
What antibiotic should be used for resistant strains of pneumonia?
AT WHAT DOSE?
WHAT IS AN ALTERNATIVE?
Co-amoxiclav.This contains amoxicillin plus clavulanic acid which is a beta lactamase inhibitor- this makes this antibiotic very effective against more resistant strains. (500/125 mg three times a day or 1.2 g intravenously three times a day).
Alternative: Levofloxacin (500 mg twice a day orally or intravenously), particularly if penicillin allergy is present. This is often used when fluoroquinolones are needed due to their broader spectrum, but they come with risks like tendinopathy and should be used cautiously.
Aside from antibiotics like clindamycin etc, what can cause C.diff?
PPI’s
What is the difference between the discharge in bacterial vaginosis and Trichomoniasis Vaginalis?
Bacterial Vaginosis Discharge:
Greyish-white, thin and watery discharge
Often has a strong fishy odor, especially after sex
Usually no itching or soreness.
Trichomoniasis Vaginalis Discharge:
Frothy, yellow-green discharge
Can have a fishy smell and may cause itching, soreness, and irritation around the vagina
Pink and frothy sputum=?
Heart Failure: the pulmonary oedema (fluid on lungs) can result in coughing up blood and requiring more pillows to sleep on to take weight off the chest
What are the most common causative organisms of Community Aquired pneumonia? (4)
Streptococcus pneumoniae: The most common bacterial cause of CAP in adults.
Haemophilus influenzae: Frequently seen in individuals with underlying lung diseases, such as COPD.
Mycoplasma pneumoniae: Often responsible for milder, atypical cases of pneumonia, especially in younger adults.
Legionella pneumophila: Causes more severe pneumonia, often linked to contaminated water sources
What antibiotics are suitable in pregnancy?
Penicillins and Cephalosporins + erythromycin
What are the indications for aminoglycosides?
Indications for Aminoglycosides
Severe Gram-negative infections(e.g., sepsis, pneumonia, urinary tract infections (pyelonephritis))
Endocarditis (in combination with other antibiotics)
Plague and tularemia
Tuberculosis (drug-resistant cases, alongside other antibiotics)
What is the therapeutic range for gentamicin?
5-10mg/L
Which aminoglycoside is given orally? and why?
Neomycin- too toxic for IV use
Reason for Oral Use: Neomycin is given orally to prepare the bowel before surgery and to treat hepatic encephalopathy. It works by reducing bacteria in the intestines, which can help prevent infection during surgery or reduce the production of toxins in liver disease
What are the side effects of aminoglycosides? (3)
1) Nephrotoxicity 2) Ototoxicity 3) Peripheral neuropathy
Aminoglycosides shouldn’t be used in…? (2)
1) Myasthenia gravis (impairs neuromuscular transmission
2) Pregnancy (ear damage)
Aminoglycosides interact with what drugs?
1) Loop diuretics and Vancomycin (ototoxicity)
2) Cisplatin, Ciclosporin and vancomycin (nephrotoxicity)
IV treatment with aminoglycosides should not exceed how many days?
7 days
Treatment should not exceed 7 days in most cases. Prolonged treatment increases the risk of renal and ototoxicity. Gentamicin and other aminoglycosides are often reviewed after 48-72 hours, with doses adjusted based on serum levels and patient response
Monitoring requirements for aminoglycosides? (3)
Monitoring Requirements for Aminoglycosides:
- Serum concentration monitoring: Measure levels 12–18 hoursafter the first dose and every 3 days, or after dose adjustments.
- Renal function: Monitor serum creatinine and creatinine clearance
- Auditory and vestibular function:Check for ototoxicity, especially in patients with prolonged therapy or at high risk
Common bacteria in meningitis? (3)
Common Bacteria in Meningitis
- Neisseria meningitidis (meningococcus)
- Streptococcus pneumoniae (pneumococcus)
- Haemophilus influenzae type b (Hib) (now rare due to vaccination)
Antibiotics used in meningitis?
Antibiotics for Meningitis
Cefotaxime (first-line treatment)
ceftriaxone(alternative if Cefotaxime is contraindicated)
Benzylpenicillin sodium if organism is sensitive eg (Streptococcus pneumoniae)
Chloramphenicol (for severe penicillin or cephalosporin allergies)
Amoxicillin or Ampicillin (for Listeria monocytogenes infections)
Name THE NON C cephalosporins?
1) Cefalexin 2) Cetrotide 3) Cefaclor 4) Cefuroxime 5) Cefixime 6) Ceftriaxone 7) Ceftaroline 8) Fosamil
Are cephalosporins broad spectrum?
Yes
Indications for cephalosporins?
Indications for Cephalosporins:
Respiratory infections: Including pneumonia and bronchitis
Meningitis: Effective against Neisseria meningitidis and Streptococcus pneumoniae
Septicemia: Often used in serious bloodstream infections
Urinary tract infections(UTIs)
Biliary-tract infections
Peritonitis
2nd or 3rd line treatment for UTI and RTI
IV for severe resistant organisms Pneumonia, meningitis, gonorrhoea
Side effects of cephalosporins? (2)
1) GI effects
2) Penicillin hypersensitivity (avoid in known allergy)
Do IV cephalosporins require approval by a microbiologist?
YES and are now mainly restricted to antibiotic associated colitis
Does warfarin interact with cephalosporins? if so, how?
YES, cephalosporins kill the gut flora responsible for synthesizing vitamin K this results in a reduction in the production of vitamin K dependent blood clotting factors-results in increased anticoagulant effect of warfarin. It is important to monitor INR levels closely and adjust the warfarin dose if needed during concurrent use
What is the first line antibiotic group for MRSA?
Glycopeptides e.g vancomycin, Teicloplanin etc
What indications are glycopeptides generally used for?
Indications for Glycopeptides
Serious Gram-positive infections, especially MRSA (methicillin-resistant Staphylococcus aureus)
Endocarditis caused by Staphylococcus or Enterococcus species
Clostridium difficile infections (oral vancomycin)
Bone and joint infections when Gram-positive bacteria are involved
What are the main side effects of glycopeptides? (5)
1) Nephrotoxicity
2) Blood disorders
3) Ototoxicity
4) ‘Red man syndrome
5) Thrombophlebitis (IV)
When would you avoid using glycopeptides? 4
elderly, history of deafness, renal impairment, pregnancy (ear damage)
What are the monitoring requirements for glycopeptides? (5)
1) FBC
2) WCC
3) Hepatic and renal function
4) Urinalysis
5) Auditory function in elderly
What drugs do glycopeptides interact with?
Ciclosporin, cisplatin, aminoglycosides, loop diuretics Suxamethonium- (Increases vancomycin conc)
What are the indications for clindamycin? (3)
what medicine class?
it is a lincosamide
indications
1) Staphylococcal joint and bone infections
2) Intra abdominal sepsis
3) Cellulitis and skin and soft tissue infections (effective against penicillin resistant streptococci)
Important side effects of clindamycin? (4)
1) Antibiotic associated colitis-REPORT diarrhoea
2) Esophageal disorders
3) Jaundice
4) SJS, rash
In what patient groups is clindamycin CI?
Existing diarrhoea Caution in middle aged/ elderly women after an operation
What are the indications for macrolides?
Respiratory infections (in addition to penicillin),
Lyme disease,
severe pneumonia (added to penicillin),
skin and soft tissue infections (alternative to penicillin)
Important side effects of macrolides? (4)
1) Antibiotic associated colitis
2) QT prolongation
3) Ototoxicity
4) Cholestatic jaundice
Why would you avoid using macrolides in myasthenia gravis?
Macrolides cause electrolyte abnormalities which can aggravate myasthenia gravis
Main CI for macrolides?
1) Hepatic impairment (cholestatic jaundice)
2) Arrhythmia (QT prolongation)
What drugs interact with macrolides?
1) CYP450 substrates
2) Drugs that prolong QT interval
What are the main indications of metronidazole? and appropriate doses? (3)
1) Antibiotic associated colitis (400mg TD 5 days)
2) Oral infections (200mg TD 3 days for gingivitis)
3) Gynecological infections e.g trichomonas vaginal infection
Main side effects associated with metronidazole? (3)
1) Neurological effects e.g peripheral and optic neuropathy
2) Mouth-Taste disturbance, furred tongue and mucositis
3) Hearing loss
Is metronidazole a CYP450 inhibitor?
NO, it is a substrate of CYP450
What happens if you drink alcohol while taking metronidazole?
‘di-sulfram like’ reaction will occur. Metronidazole inhibits the clearing of acetylaldehyde (intermediary metabolite)- this causes flushing, headache, tachycardia
How long after stopping metronidazole should you avoid alcohol?
2 days
What drugs does metronidazole interact with? (4)
1) CYP450 inhibitors
2) CYP450 inducers
3) CYP450 substrates
4) Lithium (reduces clearance of lithium resulting in toxicity)
What effect will ketoconazole have on metronidazole?
Ketoconazole is a CYP450 inhibitor, metronidazole is a substrate of CYP450 therefore ketoconazole will reduce the metabolism of metronidazole. Metronidazole is a pro-drug so this will reduce the efficacy of metronidazole.
What duration of treatment with metronidazole requires FBC and hepatic monitoring?
10 days
Are penicillins broad spectrum?
Yes
What are the main indications for penicillins? (7)
1) Tonsillitis (streptococcal)
2) Otitis media
3) Cellulitis
4) respiratory tract infections
5) Meningitis
6) Tetanus (C.diff)
7) Skin and soft tissue infections
Main side effects of penicillin’s? (2)
1) Penicillin allergy
2) CNS toxicity (convulsions, coma)-do not give intrathecal injection
Main drug interaction of penicillin’s?
Methotrexate- reduced renal excretion and increased toxicity
What are the main indications for co-amoxiclav? (3)Main side effect of co-amoxiclav?
1) Pneumonia
2) UTI (250-500mg 8hrly)
3) H.pylori (combo therapy)Same as penicillin’s + Cholestatic jaundice (no more than 14 days treatment)
What are the main indications for flucloxacillin? (3)Main side effect of flucloxacillin?
1) Skin and soft tissue infections e.g cellulitis
2) Osteomyelitis/septic arthritis
3) Endocarditis Same as penicillin’s +Cholestatic jaundice
Name two diaminopyrimidine antibiotics
1) Trimethoprim 2) Co-trimoxazole
How do diaminopyrimidines work?
Bacteriostatic-inhibit folate synthesis
Main indications of diaminopyrimidines?
Uncomplicated UTI (200mg 12 hourly) trimethoprim
RTI, pneumocystis pneumonia (co-trimoxazole)
What are the main side effects associated with diaminopyrimidines? (Trimethoprim) (2)
1) Blood disorders (look out for bruising, bleeding, ulcers etc)
2) SJS
What are the main contra indication for diaminopyrimidines? (2)
1) Pregnancy (Teratogenic-especially in first trimester)
2) Caution in folate deficiency
Drugs that interact with diaminopyrimidines?
K+ elevating drugs e.g ACE inhibitors, ARB’s
Folate antagonists e.g methotrexate Phenytoin, warfarin (reduced clearance)
Name five Quinolone antibiotics?
1) Ciproflaxacin
2) Monoflaxacin
3) Levofloxacin
4) Ofloxacin
5) Norfloxacin
Why are quinolones typically 2nd and 3rd line drugs?
Rapid resistance developing
Safety Concerns: Tendinopathy, QT interval prolongation,Neurotoxicity,
Main indications that quinolones are used for? (4)
1) Complicated UTIs and pyelonephritis
2) severe GI infections including travelers diarrhoea - (e.g., salmonella, shigella)
3) LRTI -lower respiratory tract infection - Pneumonia (only when other first-line antibiotics are inappropriate)
4) Gonorrhoea (when other options are unsuitable)
5) Prostatitis (acute bacterial)
What are the main side effects associated with quinolones? (6)
1) Gastrointestinal upset: Nausea, vomiting, and diarrhea are common, or C. diff
2)Central nervous system effects:-seizures and hallucinations
3)Inflammation and rupture of tendons-STOP
4) Prolong QT interval-arrhythmia
5) Photosensitivity
6) Peripheral neuropathy: Causes abnormal sensations like tingling, numbness, and weakness.
What is an important side effect of monoflaxacin?
Life threatening hepatotoxicity
In what conditions should quinolones be use with caution?
1) Epilepsy
2) GPD6 deficiency
3) Joint disorders e.g myasthenia gravis
4) Children and adolescents (disease of joints)
What drugs do quinolones interact with?
1) Calcium and antacids (reduce absorption)
2) Theophylline (quinolones inhibit CYP450)
3) NSAIDS
4) Prednisolone (tendon rupture)
5) QT prolonging drugs e.g amiodarone, antipsychotics etc
What is the last resort antibiotic for MRSA?
Linezolid (vancomycin resistant cocci)
What types of infections is Linezolid used for?
Complicated skin and soft tissue infections and pneumonia
1. Infections Treated with Linezolid
- Pneumonia:Especially when caused by Gram-positive bacteria and when other antibacterials like vancomycin cannot be used.
- Complicated skin and soft-tissue infections: Particularly those caused by resistant Gram-positive organisms like MRSA (Methicillin-resistant Staphylococcus aureus).
- Vancomycin-resistant Enterococcus (VRE) infections
What type of drug is linezolid?
a monoamine oxidase inhibitor (MAOI) in addition to being an oxazolidinone antibiotic.
What are the main side effects associated with Linezolid?
1) Bipolar and confusional states
2) History of seizures
3) Uncontrolled hypertension
4) Elderly (increased risk of eosinophilia)
What foods should be avoided while taking linezolid?
Tyramine rich foods
What monitoring is required for Linezolid if the treatment exceeds 14 days?
FBC monitoring unless patient has existing myelosuppression, taking blood drugs and renal impairment (check for eosinophilia)
What monitoring is required for Linezolid if treatment exceeds 28 days?
Check for optic neuropathy
What drugs does Linezolid interact with and why?
SSRIs, triptans, tricylic antidepressants, sympathomimetics, buspirone, opioids, pethidine, antipsychotics (MAOI inhibitor)
Which TWO drugs cause peripheral neuropathy?
Antibiotics Causing Peripheral Neuropathy:
Fluoroquinolones(e.g., ciprofloxacin, levofloxacin): Commonly associated with peripheral neuropathy, particularly with prolonged use.
Chloramphenicol: Rarely causes peripheral neuropathy, especially with prolonged or high-dose therapy.
Ethambutol: Known to cause sensory peripheral neuropathy, especially with long-term use.
Dapsone: Can cause a motor axonal neuropathy, particularly with high doses or long-term treatment
Metronidazole and nitrofurantoin
What type of infection is nitrofurantoin used for and what are the typical doses?
1st line for UTI (100mcg m/r BD for 3 days) and as prophylaxis for UTI (50-100mg nightly for max 6 months)
What are the main side effects associated with nitrofurantoin? (4)
1) Dark yellow/ brown urine
2) Pulmonary reactions
3) Peripheral neuropathy
4) Hepatitis
In what patient groups would nitrofurantoin be an inappropriate choice? (4)
Patient Groups Where Nitrofurantoin is Inappropriate:
Patients with Renal Impairment: Contraindicated in those with an eGFR of less than 45 ml/min/1.73m², as its efficacy decreases, and the risk of side effects increases.
Pregnant Women at Term (38-42 weeks): Risk of haemolytic anaemia in newborns.
Patients with G6PD Deficiency: Risk of haemolysis.
Severe Hepatic Impairment: Risk of liver damage
What are the TWO monitoring requirements for Long term nitrofurantoin use?
Hepatic and pulmonary function
In what patient groups would a specimen and culture be collected before treatment for UTI?
Men,
pregnant women,
children <3,
Upper UTI
Recurrent UTIs: reresistant organism suspected e.g Klebsiella suspected
What are the treatment options for an uncomplicated UTI in a child >3mo?
Trimethoprim, Nitrofurantoin, Cefalexin, amoxicillin
What are the treatment options for an uncomplicated UTI in a child <3mo?
IV ampicillin with gentamicin or cefotaxime in hospital, then oral treatment
What are the antibiotic treatment options for recurrent UTI’s in children?
Trimethoprim or nitrofurantoin
Name FIVE tetracyclines?
Tetracyline, doxycycline, minocycline, lymecyline, oxytetracyline
What are the main indications for tetracylines? (6)
1) Chlamydia and PID
2) Acne
3) LRTI (including COPD)
4) Malaria,
5) lyme disease,
6) rickettsia
Main side effects associated with tetracylines? (5)
1) Photosensitivity
2) Esophageal irritation
3) Hepatotoxicity
4) benign intracranial pressure- headache and visual disturbances-STOP
5) Discoloration of tooth enamel
In what patient groups would you want to avoid tetracylines?
1) Children <12 (binds to teeth)
2) Pregnancy and breastfeeding
Name TWO conditions that require prolonged courses of antibiotics?
TB
osteomyelitis
Antibiotic used to prevent pneumococcal infection in sickle cell disease?
Phenoxymethylpenicillin,
If contra indicated then erythromycin
Antibiotic used as prevention for early onset neonatal infection?
IV : Benzylpenicillin or ampicillin in combination with gentamicin, which provides broad coverage against Gram-positive bacteria like Group B Streptococcus and Gram-negative bacteria like Escherichia coli.
Name FOUR beta lactam antibiotics?
1) Penicillins
2) Cephalosporins
3) Carbapenems
4) Monobactams
What is the main use for fusidic acid?
narrow spectrum for staph infections, topically on the skin or eye or IV/oral for osteomyelitis and endocarditis
What is the first line treatment for C.diff?
vancomycin or fidoxamicin
What can a tobramycin dry powder inhaler be used for?
Pseudomonas aeruginosa lung infection in cystic fibrosis.
Name TWO carbapenems?
Imipenem and Meropenem
Name TWO cephalosporins that can be used for CNS infections?
1) Cefotaxime 2) Ceftriaxone
Which cephalosporin has good activity against haemophillus influenza?
Cefotaxime (or ceftriaxone)
Which cephalosporin should be used in history of hypercalciuria (history of renal stones)?
Ceftriaxone
What is the maximum duration of treatment for fusidic acid?
10 days
What are the specific monitoring requirements for minocycline if the treatment is longer than 6 months?
Monitor every 3 months for
hepatotoxicity,
pigmentation of the skin and
systemic lupus erythromtosus
Name TWO antimycobacterials?
- Isoniazid
Use: First-line treatment for TB.
2. Rifampicin
Use: Essential in TB therapy and other mycobacterial infections.
3. Ethambutol
Use: Commonly used in combination therapy for TB.
4. Pyrazinamide
Use: Key part of short-course TB treatment.
5. Rifabutin
Use: For TB, especially in patients intolerant to rifampicin, and for mycobacterium avium complex (MAC).
6. Rifapentine
Use: Similar to rifampicin, often used for latent TB.
7. Clofazimine
Use: Primarily for leprosy, has anti-inflammatory effects.
8. Dapsone
Use: A key drug for leprosy, used in multidrug therapy
Name the three antibiotics that can be used in lyme disease?
1) doxycycline
2) amoxicillin
3) azithromycin
Should be used in this order unless <9 years (avoid doxycycline)
Name SEVEN bacteria that can cause UTI?
1) E coli
2) Staph saprophyticus
3) Proteus
4) Klebsiella
5) Pseudomonas aeruginosa
6) Staph epidermidus
7) Enterococcus Faecalis
What is the antibacterial prophylaxis and treatment of choice for animal bites?
Co-amoxiclav (if penicillin allergic- doxycyline + metronidazole for up to 5 days) and give the tetanus jab
What is the treatment for a >50 year old with meningitis?
First-line treatment
Ceftriaxone (2g IV every 12 hours)
Add Amoxicillin or Ampicillin (2g IV every 4 hours) to cover (Listeria monocytogenes).
Duration:
Usually 10-14 days, depending on the clinical response.
Cefotaxime or ceftriaxone AND Amoxicillin or Ampicillin Consider adding vancomycin (10 days)
How long is the initial phase of TB treatment?
Duration: 2 months
Regimen: Four-drug therapy (Rifampicin, Isoniazid with Pyridoxine, Pyrazinamide, Ethambutol).
This phase is followed by a continuation phase of 4 months with Rifampicin and Isoniazid
How long is the second phase of TB treatment?
4 months
Rifampicin and Isoniazid
What drugs are used in the initial phase of treatment for TB?
Isonazid (300mg OD)
Rifampicin (<50kg=450mg OD, >50kg=600mg OD)
Pyrazinamide (<50kg=1.5g, >50kg=2g OD)
Ethambutol (15mg/kg OD)
What drugs are used in the second phase of treatment for TB?
Isonazid (300mg OD)
Rifampicin (<50kg=450mg OD, >50kg=600mg OD)
Which TB drugs cause liver toxicity?
Isonazid
Rifampacin
Pyrazinamide
Which TB drugs cause peripheral neuropathy?
Isonazid
Which TB drugs cause occular toxicity?
Ethambutol
What are the monitoring requirements for TB treatment?
Plasma levels e.g ethambutol
Urinalysis
Visual acuity testing
Blood counts
Liver and hepatic function
Auditory function in the elderly
What is the duration of treatment for extrapulmonary TB?
CNS Tuberculosis Treatment
Duration: 12 months (2 months initial, 10 months continuation).
Drugs: Rifampicin, Isoniazid, Pyrazinamide, Ethambutol.
Steroids: Dexamethasone or Prednisolone tapered over 4–8 weeks.
Surgery: If raised intracranial pressure or spinal instability
What is a specific Contra indication of pyrazinamide?
Acute attack of gout
Name the antibiotics in the aminoglycoside class
Amikacin
Gentamicin
Neomycin
Streptomycin
Tobramycin
What aminoglycosides are active against Pseudomonas and what one is the treatment of choice?
For aminoglycosides that are active against Pseudomonas aeruginosa, the following are commonly used:
Gentamicin
Tobramycin
Amikacin
Among these, Tobramycin is often considered the treatment of choice for infections caused by Pseudomonas aeruginosa due to its effectiveness, particularly in respiratory infections like cystic fibrosis.
What aminoglycoside is active against TB?
Aminoglycoside active against TB
Streptomycin:Commonly used in TB treatment, particularly for multidrug-resistant TB.
Alternatives: Amikacin, Kanamycin (used in drug-resistant TB).
Streptomycin(mainly reserved for this indication)
Can aminoglycosides be given orally?
No- destroyed by the gut so must be given via injection
except neomycin which can be given orally
Is gentamicin a broad or narrow antibiotic?What strains does it have poor activity against?
Broad but it is inactive against anaerobes and poor activity against haemolytic streptococci and pneumococci, but Very good for gram negative organisms
Which aminoglycoside is used for encocarditis?If it is resistant to this, what is an alternative aminoglycoside?
Which aminoglycoside is used for endocarditis?
Gentamicin: Used in combination with other antibiotics for gram-positive endocarditis (e.g., with penicillin or teicoplanin).
Alternative: If resistant or high-level aminoglycoside resistance occurs, Streptomycin or Amikacin may be considered as alternatives
Are aminoglycosides more active against gram positive or gram negative?
More Active Against: Gram-negative bacteria.
Examples: Pseudomonas aeruginosa, Escherichia coli.
Use in Gram-positive infections: Often combined with other antibiotics (e.g., gentamicin with penicillin for endocarditis) for synergy
Gram negative but are broad
Can neomycin be given IV?
No, Neomycin cannot be administered intravenously.
Forms: It is used orally or topically.
Uses: For reducing gut bacteria before surgery or treating hepatic coma (oral), and for skin, eye, or ear infections (topical).
Reason: It is highly toxic systemically, making IV use inappropriate
No too toxic Can only be used for skin/mucous membrane infections… However BNF states the cream is less suitable for prescribing(Can also be used to reduce the bacterial population of the colon prior to bowel surgery or in hepatic impairment)
What is the problem with using aminoglycosides in myasthenia gravis?
Problem:Aminoglycosides (e.g., gentamicin) can impair neuromuscular transmission, worsening muscle weakness in myasthenia gravis.
Risk: This may lead to severe symptoms such as respiratory failure or even a myasthenic crisis.
Caution: Aminoglycosides should be avoided unless no alternative exists
Contraindicated May impair neuromuscular transmission
What antibiotics can be used for prophylaxis in rheumatic fever?
Pen V or sulfadiazine
What anitbiotics can be used for prevention of secondary case of menincoccal meningitis?
Ciprofloxacin or rifampicin Or IM ceftriaxone (unlicensed)
