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 or hospital acquired)?
BROAD SPEC antibiotics: e.g. tazocin (pipericillin and tazobactam) if allergic: meropenem
If MRSA suspected: add Vancomycin
Anaerobic: Metronidazole
Meningococcal: Benzylpenicillin
Pen/Ceph allergy: chloramphenicol
What antibiotic Is very good against anaerobic bacteria so usually infections of the colon?
Metronidazole - V high anaerobic activity, narrow spectrum
Used for bacteria growing where there isn’t much oxygen: Gut (H pylori, Chron’s), Bacterial vaginosis, Leg ulcers
How is bacterial meningitis empirically treated?
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
What is the treatment for meningococcal meningitis?
Benzylpenicillin or cefotaxime 2nd line: Chloramphenicol For 7 days
What is the treatment for pneumococcal meningitis?
- Benzylpenicillin
- Cefotaxime (OR ceftriaxone)
- If allergic: chloramphenicol
- If resistant: vancomycin/rifampicin
For 14 days consider adding dexamethasone
What is the treatment for meningitis caused by haemophilus influenza?
Cefotaxime (OR ceftriaxone) for 10 days
Consider adding dexamethasone
What antibiotics are used in endocarditis (infection of the heart)?
1) amoxicillin
If resistant MRSA or pen allergy: vancomycin
2) staph: flucloxacillin, strep: benzylpenicillin
^ All +/- low-dose gentamicin hence the lower target level range for gentamicin in endocarditis (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?
First episode: oral Metronidazole (high anaerobic activity)
Second episode/2nd line: oral Vancomycin
Use together if combo not worked: oral Fidaxomicin ALL FOR 10-14 DAYS DURATION
Which antibiotics are commonly used for GU infections?
Azithromycin- used in chlamydia, gonorrhoea
Doxycycline- alternative in chlamydia, pelvic inflammatory disease, syphilis
Metronidazole- used for bacterial vaginosis, pelvic inflammatory disease
What class of AB’s is Amikacin? When is amikacin usually indicated?
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 if endocarditis)
What is the target pre-dose trough concentration of gentamicin? (multiple daily dosing)
under 2 mg/L (<1mg/L if endo)
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?
Nitrofurantoin: okay to use but avoid at term
Trimethoprim: Teratogenic risk in first trimester as it is a folate antagonist
Cefalexin: a cephalosporin, these are safe in pregnancy
Cranberry juice or other cranberry products are not recommended as no evidence to support their use
What classes, other than penicillins, do we have to be wary of with penicillin allergic patients?
Cephalosporins- cefalexin, cefadroxil, ceftriaxone, cefixime, cefotaxime
All cephalosporins begin with C
(0.5-6.5% cross-sensitiviry)
What is Co-trimoxazole? What is it used for?
Contains SULFAMETHOXAZOLE and TRIMETHOPRIM!
Resistance to sulphonamides has increased so there are restrictions on the use of co-trimoxazole.
LIMITED USE:It IS indicated for: Pneumonia caused by p.jiroveci/ carinii.
Also for toxoplasmosis + nocardiasis
Should only be used in bronchitis exacerbation/ UTI’s/ otitis media in children when culture and sensitivities evident
ONLY use when there is GOOD EVIDENCE to use this COMBO rather than just a single due to resistance!
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
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
What happens if a patient on clindamycin develops diarrhoea?
Antibiotic associated colitis with clindamycin can be fatal- discontinue immediately + start vancomycin
Why antibiotic has been associated with Myopathy/ Muscle effects?
Daptomycin monitor creatinine kinase every 2 days if muscle effects reported
Which antibiotics can cause cholestatic jaundice?
Co-amoxiclav
Nitrofurantoin
Flucloxacillin ( even upto 2 months after)
Be careful in liver patients
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.
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)- retinal detachment
Ethambutol (used for TB)- ocular toxicity
Rifampicin- colours tears/ contacts red
Rifabutin- Uveitis (eye inflammation)
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 TWO very important safety warnings with QUINOLONES (ciprofloxacin, levofloxacin)?
May induce CONVULSIONS especially if also taking NSAIDS - even in those that are not epileptic.
Caution in EPILEPSY.
Caution with THEOPHYLLINE as also causes seizures.
TENDON DAMAGE
Tendonitis, tendon rupture (NB: this has also been reported with prednislone!)( also can PROLONG QTc interval- this is a caution)
When should patients discontinue treatment with Quinolones?
If any of the following occur: Psychiatric reactions (hallucinations, anxiety, depression) Neurological reactions (tremor, asthenia [abnormal weakness])
WHAT ANTIOBIOTICS CAN CAUSE QT PROLONGATION??!
MACROLIDES especially prone: Erythromycin, Clarithromycin, Azithromycin
QUINOLONES: Ciprofloxacin, Levofloxacin, especially Moxifloxacin
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 foodsRemember: Linezolid will still have interactions/ tyramine effects 2 weeks after discontinuation!!
What can happen if VANCOMYCIN is infused too rapidly?
Flushing of upper body= RED MAN SYNDROMEAlso:Severe HypotensionWheezingPruritisPain/ muscle spasm in back
After how many doses should Vancomycin plasma levels be measured?
After 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?
Ototoxicity
Nephrotoxicity
Obviously avoid use of vancomycin and gentamicin together!
Ototoxic drugs:Loop diuretics- furosemide!!
Nephrotoxic drugs:CICLOSPORINPlatinum chemotherapy
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
Nitrofurantoin - Use these with caution in those with liver dysfunction!!
Which antibiotics are commonly used to treat acne??
Tetracyclines most common: tetracycline, doxycycline, oxytetracycline, lymecycline (trimethoprim for resistant acne)
Erythromycin (a macrolide) sometimes used
What conditions can Tetracyclines exacerbate?
Systemic Lupus Erythematosus Myasthenia Gravis (increased muscle weakness)
Which antibiotics can cause photosensitivity?
Doxcycline
Demeclocycline
Which antibiotics are not recommended in children and adolescences under 18 years old? And why?
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?
WEEKLY Full Blood Counts due to risk of blood disorder/ anaemia
Which antibiotics may cause a false positive result on urinary GLUCOSE tests- i.e. be careful when testing for diabetes?
CEPHALOSPORINSCefalexin, Ceftriaxone etc
Which antibiotic is a FOLATE SYNTHESIS INHIBITORS and is therefore teratogenic?
Trimethoprim
Co-trimoxazole (contains sulfamethoxazole and trimethoprim)
Therefore AVOID in pregnancy- especially first trimester when folate is needed
What frequency of administration is Vancomycin given?
BD - 12 hourly due to long half life
Teicoplanin: even longer acting: OD dosing after loading dose
Name 2 Glycopeptide antibiotics?
Vancomycin
Teicoplanin (less nephrotoxic than vancomycin)
What are the target pre-dose TROUGH levels for vancomycin?? (only trough levels are used with Vancomycin)
10 - 15 mg/ L
First line antibiotic for Cellulitis?
Flucloxacillin (250-500mg QDS)If penicillin allergic: Clindamycin
Which antibiotics/ antifungals may cause STEVENS JOHNSON SYNDROME (skin rash)?
Co-trimoxazole Clindamycin Fluconazole
What are some of the more common side effects experienced with Metronidazole (its quite an unpleasant antibiotic)?
Lots of GI disturbance- sick, stomach pain
Mouth effects: Taste disturbance, oral mucositis (mouth ulcers), furry tongue
Alcohol- disulfiram like reaction
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 Neurones
Nitrofurantoin: Pulmonary Fibrosis
Cholestatic Jaundice
Peripheral Neuropathy
also can cause Vit B/ Folate deficiency
Which antifungal medication can cause QT prolongation?
FLUCONAZOLE
What antibiotics/ antifungals should be stopped if signs ofdark urinevomitingfatigueanorexia occur?
This indicated LIVER FAILURE
Discontinue drugs that are hepatotoxic: Itraconazole Fluconazole Ketoconazole (no longer available oral)! Terbinafine Rifampicin Isoniazid Pyrizinamide (R.I.P liver: TB drugs)
Which antifungal is cautioned in patients at a high risk of heart failure?
ITRACONAZOLE can worsen this
More at risk if on negatively ionotropic drug e.g. CCB
What skin condition may Terbinafine (antifungal) exacerbate?
Psoriasis
Which antifungal can cause renal toxicity?
AMPHOTERICIN Can also cause electrolyte disturbance: Hypokaleamia and hypomagneseamia
Which antimalarials are unsuitable in patients with epilepsy/ has a history of epilepsy?
CHLOROQUINE
MEFLOQUINE
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 can both be used at normal doses in pregnancy as benefit of malaria prophylaxis outweighs any risk
BUT recommend FOLIC ACID 5mg to be taken with proguanil
What does the antimalarial malarone contain?
Proguanil & AtovaquoneThis is fine to use in epilepsy; does not contain chloroquine or mefloquine
What is the most common causative bacteria of a UTI?
E. coli
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)
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
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?
Co-amoxiclav.This contains amoxicillin plus clavulanic acid which is a beta lactamase inhibitor- this makes this antibiotic very effective against more resistant strains.
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= thick, white and fishy discharge- cottage cheese like in appearance
Trichomoniasis Vaginalis= frothy-smell, green/ yellow coloured!
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? (2)
Streptococcus pneumoniae
Haemophilus influenzae
Atypical (less common): Chlamydia pneumoniae
Mycoplasma pneumoniae
Legionella
What antibiotics are suitable in pregnancy?
Penicillins and Cephalosporins + erythromycin
What are the indications for aminoglycosides?
Used for serious infections CNS infections e.g meningitis TB (streptomycin) Pyelonephritis pneumonia endocarditis
What is the therapeutic range for gentamicin?
5-10mg/L
Which aminoglycoside is given orally? and why?
Neomycin- too toxic for IV use
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
Monitoring requirements for aminoglycosides? (3)
1) Plasma concentration (18-24 hours after dose)
2) Renal function (especially during periods of dehydration)
3) Auditory and vestibular function
Common bacteria in meningitis? (3)
1) Neisseria meningitidis
2) Streptococcus pneumoniae
3) Haemophilius influenza
Antibiotics used in meningitis?
Benzylpenicillin, cefotaxime, chloramphenicol
Name 8 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?
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.
What is the first line antibiotic group for MRSA?
Glycopeptides e.g vancomycin, Teicloplanin etc
What indications are glycopeptides generally used for?
MRSA
C.diff
endocarditis
surgical prophylaxis (MRSA risk)
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?
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 (lincosamide)? (3)
1) Staphylococcal joint and bone infections2) 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) Jaundice4) 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 colitis2) QT prolongation 3) Ototoxicity4) 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 inducers3) CYP450 substrates4) 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) RTI5) Meningitis6) 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)RTI, pneumocystis pneumonia (co-trimoxazole)
What are the main side effects associated with diaminopyrimidines? (2)
1) Blood disorders (look out for bruising, bleeding, ulcers etc)2) SJS
What are the main CI 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’sFolate 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
Main indications that quinolones are used for? (4)
1) UTI 2) severe GI infections including travelers diarrhoea3) LRTI4) Gonorrhoea
What are the main side effects associated with quinolones? (5)
1) C. diff2) Neurological-seizures and hallucinations3) Inflammation and rupture of tendons-STOP4) Prolong QT interval-arrhythmia 5) Photosensitivity
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
What type of drug is linezolid (HINT-psychiatric effects)
MAOI
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?
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 urine2) Pulmonary reactions 3) Peripheral neuropathy 4) Hepatitis
In what patient groups would nitrofurantoin be an inappropriate choice? (2)
1) Pregnancy 2) CI in renal impairment
What are the TWO monitoring requirements for LT 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, resistant 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? (4)
1) Chlamydia and PID 2) Acne 3) LRTI (including COPD)4) Malaria, lyme disease, rickettsia
Main side effects associated with tetracylines? (5)
1) Photosensitivity 2) Esophageal irritation 3) Hepatotoxicity 4) benign intracranial pressure- headache and visual disturbances-STOP5) 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 and osteomyelitis
Antibiotic used to prevent pneumococcal infection in sickle cell disease?
Phenoxymethylpenicillin, if CI then erythromycin
Antibiotic used as prevention for early onset neonatal infection?
Benzylpenicillin (IV)
Name FOUR beta lactam antibiotics?
1) Penicillins2) Cephalosporins3) Carbapenems4) 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?
Metronidazole(or vancomycin or fidoxamicin)
What can a tobramycin dry powder inhaler be used for?
Pseudomonas lung infection in CF
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?
Cefaclor
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?
Clofazimine and Dapsone (both used for leprosy)
Name the FOUR antibiotic groups that can be used in lyme disease?
1) Macrolides2) Amoxicillin3) Macrolides
Name SEVEN bacteria that can cause UTI?
1) E coli2) Staph saprophyticus3) Proteus4) Klebsiella5) 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?
Cefotaxime or ceftriaxone AND Amoxicillin or Ampicillin Consider adding vancomycin (10 days)
How long is the initial phase of TB treatment?
2 months
How long is the second phase of TB treatment?
4 months
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 (same as initial)
Which TB drugs cause liver toxicity?
IsonazidRifampacinPyrazinamide
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 ethambutolUrinalysisVisual acuity testingBlood countsLiver and hepatic functionAuditory function in the elderly
What is the duration of treatment for extrapulmonary TB?
10 months
What is a specific CI of pyrazinamide?
Acute attack of gout
Name the antibiotics in the aminoglycoside class
AmikacinGentamicinNeomycinStreptomycinTobramycin
What aminoglycosides are active against Pseudomonas and what one is the treatment of choice?
Gentamicin - treatment of choice AmikacinTobramycin - usually via inhalation in CF
What aminoglycoside is active against TB?
Streptomycin(mainly reserved for this indication)
Can aminoglycosides be given orally?
No- destroyed by the gut so must be given via injection
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 pneumococciVery good for gram negative organisms
Which aminoglycoside is used for encocarditis?If it is resistant to this, what is an alternative aminoglycoside?
Gentamicin plus another antibioticStreptomycin is an alternative if resistant to gentamicin
Are aminoglycosides more active against gram positive or gram negative?
Gram negative but are broad
Can neomycin be given IV?
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?
ContraindicatedMay 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)
What antibiotic can be used for prevention of secondary infection for Group A strep?
Pen V
What antibiotic can be used for prevention of secondary infection in Influenza Type B?
Rifampicin
What antibiotic can be used for prevention of secondary cases of diphtheria in non-immune patients?
Erythromycin
What is pertussis?
Whooping cough
What antibiotic is used for prophylaxis of pertussis (whooping cough)?
Clarithromycin