Antibiotics

Question 1

which type of penicillin (V vs G) is more sensitive to acid degradation?

Answer 1

pen G

*why it is usually injected rather than taken orally

Question 2

which penicillin has the best gram-neg spectrum?

Answer 2

amicillin

Question 3

which drugs are cross-allergenic with penicillin?

Answer 3

cephalosporins

Question 4

which drugs are NOT cross-allergenic with penicillin?

Answer 4

-ampicillin and erythomycin

Question 5

which penicillin is useful against penicillinase-producing bugs such as staph?

Answer 5

dicloxacillin

Question 6

which penicillin is specific for pseudomonas infections

Answer 6

carbenicillins

Question 7

under what circumstances is prohylaxis required?

Answer 7

• prosthetic valves
• previous endocarditis
• pulmonary shunts

Question 8

under what circumstances is prophylaxis NOT required?

Answer 8

• cardiac pacemakers
• rheumatic fever WITHOUT valvular dysfunction
• mitral valve prolapse without valvular regurgitaiton

Question 9

how do bacteriocidal agents such as Penicillins work?

Answer 9

kill rapidly growing cells by inhibiting cell wall synthesis

Question 10

how do bacteriostatic agents such as tetracycline work?

Answer 10

limit population growth, but do not kill bugs by interfering with protein synthesis on bacterial ribosomes

Question 11

how do antifungals like nystatin work?

Answer 11

bind to ERGOSTEROL in fungal cell walls to weaken the wall

Question 12

bacteriostatic agents like sulfonamides compete with what which causes what?

Answer 12

compete with PABA in folic acid syntesis which results in folic acid deficiency

Question 13

what are symptoms seen during allergic reactions to penicillins?

Answer 13

dermatitis
stomatitis
bronchconstriciton
cardiovascular collapse

Question 14

what agent produces GI upset and pseudomonas colitis?

Answer 14

clindamycin

Question 15

which agents are most likely to cause superinfections?

Answer 15

tetracyclines *broad spec

Question 16

which agents are least likely to cause superinfections?

Answer 16

narrow spec like pen G

Question 17

aplasitc anemia is associated with what?

Answer 17

chloramphenicol

Question 18

liver damgage is associated with what?

Answer 18

tetracycline

Question 19

erythromycin estolate is associated with what?

Answer 19

allergic cholestatic hepatitis

Question 20

what happens with pen and tetracycline are given together?

Answer 20

cancel each other out due to opposing mechanisms of actions

Question 21

what does probenecid alter the rate of ?

Answer 21

renal clearance of penicillin

Question 22

what reduces the effectiveness of tetracyclines?

Answer 22

ingestion of antacids or dairy products

Question 23

what enhances the action of coumarin?

Answer 23

broad spec antibiotics bc of the reduction of Vit K sources

Question 24

what dec the effectiveness of oral contraceptives?

Answer 24

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

Question 25

what do macrolides such as erythromycin do?

Answer 25

inhibit metabolism of drugs such as seldane and digoxin

Question 26

what med is an antiviral used for various forms of herpes?

Answer 26

acyclovir

Question 27

what drugs are used for the treatment of candadiasis?

Answer 27

fluconazole or ketoconazole