Antibiotics Flashcards
What are the safest classes of antibiotics to use in pregnancy?
Penicillins
and
Cephalosporins (cefalexin, ceftriaxone, cefadroxil)- all but Cefopime a 4th generation cephalosporin
What antibiotic treatment is indicated for septicaemia (community or hospital acquired)?
BROAD SPEC antibiotics: e.g. Piptaz (pipericillin and tazobactam)
If MRSA suspected: add Vancomycin
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,
2) If penicillin allergy- CEFOTAXIME (a cephalosporin)
3) 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?
Cefotaxime (OR ceftriaxone)
(or if bacteria is penicillin sensitive: Benzylpenicillin)
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)?
Usually Amoxicillin or Flucloxicillin or benzylpenicillin
PLUS LOW DOSE gentamicin- hence the lower target level range for gentamicin in endocarditis!
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
What is the target pre-dose trough concentration of gentamicin? (multiple daily dosing)
under 2 mg / L
What is the target One hour peak conc of gentamicin in treatment of ENDOCARDITIS? and target trough level?
Peak: 3 - 5 mg/L
Trough:
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
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
(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 CEF
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 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 & 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
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
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. 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 foods
Remember: 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 SYNDROME
Also: Severe Hypotension Wheezing Pruritis Pain/ 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:
CICLOSPORIN
Platinum 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
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
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)
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?
CEPHALOSPORINS
Cefalexin, 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 of dark urine vomiting fatigue anorexia
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
As 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 hypmagneseamia
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 & Atovaquone
This 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
