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)