Penicillins Flashcards
How does penicillins work ?
interfere with bacterial cell wall synthesis.
Broad spectrum+bactericidal
Are penicillins useful in CNS infections?
No, except meningitis
Name narrow spectrum (beta-lactamase sensitive) penicillins ?
Pen-V
Benzylpenicilin Pen-G
Name broad spectrum ( inactivated by beta-lactamase) penicillins ?
ampicillin
amoxicillin
Name penicillinase-resistant penicillin ?
flucloxacillin
Name antipseudomonal (extended spectrum) penicillins ?
piperacilin ( with tazobacatam)
Ticaricillin ( with clavulanic acid)
When would patient be considered to have true allergy to penicillin ? what are the clinical features ?
Immediate rash, anaphylaxis, hives
If a patient has true allergy to penicillins, what other classes of antibiotics should be avoided ?
cephalosporins, carbapanems, monobactams
Patient comes in and says to you they have started taking amoxicillin 4 days ago and they developed minor rash, would this be considered true penicillin allergy ?
no, may not be allergic if minor rash, small, not itchy and non-confluent or rash after 72 hours
Why penicillins cannot be given as intrathecal injection ?
encephalopathy: cerebral irritation can be fatal
Why broad spectrum antibiotics ( amoxicillin, ampicillin) should not be given as blind therapy for sore throats ?
because causes maculopapular rash in granular fever ( causes by Epstein Barr virus)
How should ampicillin be taken ?
before food
Co-amoxiclav is active against… ?
beta-lactamase producing strains, its broader spectrum than amoxicillin on its own
What is important side effect of co-amoxiclav ?
cholestatic jaundice: usually self limiting; higher risk if given for more than 14 days
Which narrow spectrum penicillin can be given for tonsillitis or streptococcal throat ?
Pen V
