Antibiotics Flashcards
which type of penicillin (V vs G) is more sensitive to acid degradation?
pen G
*why it is usually injected rather than taken orally
which penicillin has the best gram-neg spectrum?
amicillin
which drugs are cross-allergenic with penicillin?
cephalosporins
which drugs are NOT cross-allergenic with penicillin?
-ampicillin and erythomycin
which penicillin is useful against penicillinase-producing bugs such as staph?
dicloxacillin
which penicillin is specific for pseudomonas infections
carbenicillins
under what circumstances is prohylaxis required?
- prosthetic valves
- previous endocarditis
- pulmonary shunts
under what circumstances is prophylaxis NOT required?
- cardiac pacemakers
- rheumatic fever WITHOUT valvular dysfunction
- mitral valve prolapse without valvular regurgitaiton
how do bacteriocidal agents such as Penicillins work?
kill rapidly growing cells by inhibiting cell wall synthesis
how do bacteriostatic agents such as tetracycline work?
limit population growth, but do not kill bugs by interfering with protein synthesis on bacterial ribosomes
how do antifungals like nystatin work?
bind to ERGOSTEROL in fungal cell walls to weaken the wall
bacteriostatic agents like sulfonamides compete with what which causes what?
compete with PABA in folic acid syntesis which results in folic acid deficiency
what are symptoms seen during allergic reactions to penicillins?
dermatitis
stomatitis
bronchconstriciton
cardiovascular collapse
what agent produces GI upset and pseudomonas colitis?
clindamycin
which agents are most likely to cause superinfections?
tetracyclines *broad spec
which agents are least likely to cause superinfections?
narrow spec like pen G
aplasitc anemia is associated with what?
chloramphenicol
liver damgage is associated with what?
tetracycline
erythromycin estolate is associated with what?
allergic cholestatic hepatitis
what happens with pen and tetracycline are given together?
cancel each other out due to opposing mechanisms of actions
what does probenecid alter the rate of ?
renal clearance of penicillin
what reduces the effectiveness of tetracyclines?
ingestion of antacids or dairy products
what enhances the action of coumarin?
broad spec antibiotics bc of the reduction of Vit K sources
what dec the effectiveness of oral contraceptives?
antibiotics such as amicillin due to suppression of normal GI flora involved in the recycling of active steroids from bile conjugates, leading to more rapid excretion of the steroids from the body
