Answer to Question 1
ANS: C
The combination therapy of penicillin and probenecid allows the penicillin to remain in the body longer, which enhances drug availability and action. The combination may be used advantageously in treating serious or resistant infections. Probenecid inhibits the excretion of penicillin, slows down the excretion of penicillin, and does not affect absorption or toxic effects.
Answer to Question 2
ANS: A
Cephalosporins may be used with caution as alternatives when patients are allergic to the penicillins, but cephalosporins are chemically similar in structure to penicillins and may produce a cross sensitivity and/or allergic reaction. Aminoglycosides, sulfonamides, and quinolones do not tend to produce cross sensitivities.