DRUG-INTERACTIONS WITH ANTIBACTERIAL AGENTS

Antibacterial drugs, such as quinolones, macrolides, rifampin, isoniaz id, and trimethoprim-sulfamethoxazole, can interact with other drugs i n a wide variety of clinically significant ways. They are frequently a dministered with other prescription and nonprescription medications. A ntibacterial agents may interact by causing a change in the pharmacoki netics or pharmacodynamics of a second drug. In other cases, the antim icrobial may be affected by the action of another drug. Interactions i nvolving antimicrobials often result from alterations in the absorptio n of the antimicrobial from the gastrointestinal tract or changes in t he hepatic metabolism or renal elimination of the drugs concurrently a dministered. While certain classes of antibacterial drugs are known to interact with many other drugs, the interaction potential of most cla sses of antimicrobials is not uniform among members of the class. This diversity in interaction potential provides the clinician with an opp ortunity to avoid potential interactions by means of appropriate drug selection. An understanding of the common, clinically significant drug interactions involving antibacterial agents will enable the physician to avoid unnecessary adverse drug reactions.