THERAPEUTICS - penicillin Flashcards
what class is penicillin?
beta-lactam
what is penicillins mechanism of action?
inhibits cross linking peptides
inactivates autolysin inhibitors
rapidly diving organisms
what spectrum does penicillin have?what does it target?
narrow spectrum
targets:
most gram +ve cocci
gram +ve bacilli
anaerobic potential
what are the preparations of penicillin?
penicillin G - benzylpenicillin
penicillin V - phenoxymethylpenicillin
procaine/ benzathine penicillin
what is the half life of penicillin?
G - 30mins
V - 30-60mins
when would you prescribe pen G?
severe infection
what are signs of hypersensitivity immediate reaction to penicillin?
nausea/ vomiting
ertyhema
wheeze
laryngeal oedema
hypotension
angioedema
bronchospasm
cardiovascular collapse
what are signs of hypersensitivity delayed reaction to penicilin?
vesicular
bullous
articarial
haemolytic anaemia
what are risk factors for hypersensitivity to penicillin?
multiple drug allergies
atopic disease
asthma
allergic rhinitis
nasal polyps
when someone has a penicillin allergy what must the report this on?
yellow card reporting scheme by MHRA
what is the dose of penicillin V?
500mg
6 hourly
3-5 days
what are the 3 main evasion mechanisms of penicillin?
- reduced drug binding to penicillin binding proteins
- hydrolysis of the drug by beta lactamase enzymes
- development of a tolerance by disabling their autolysis mechanism
what are penicillins interactions?
NSAIDs
warfarin
methotrexate
oral contraceptive
what are common unwanted effects of penicillin?
diarrhoea
nausea
skin rash
toxicity in renal failure
what are indications of penicillin?
oral infections
acute sore throat
recurrent cellulitis
acute sinusitis
