Final answer:
Synergistic effects enhance the efficacy of drugs working together, exemplified by the combination of trimethoprim and sulfamethoxazole. Antagonistic effects impair drug effectiveness, such as when antacids reduce the absorption of antimicrobials. Avoiding antagonistic combinations is critical to preventing superinfections.
Step-by-step explanation:
Difference Between Synergistic and Antagonistic Drug Interactions
The synergistic effect in antimicrobial therapy occurs when two drugs work better together than either alone, resulting in an enhanced therapeutic effect. A classic example is the combination of trimethoprim and sulfamethoxazole, which individually exhibit bacteriostatic activity but together act as a bactericidal agent. On the contrary, antagonistic interactions happen when two substances interfere with each other's activity, reducing effectiveness or increasing toxicity.
Antagonism can result from drug-drug interactions, such as when antacids affect the absorption of certain antimicrobials in the stomach, thereby reducing their effectiveness. It's crucial to avoid antagonistic combinations, especially with broad-spectrum antimicrobials, to prevent the risk of superinfections like candidiasis or infections caused by Clostridium difficile.