Final answer:
The medication that combines trimethoprim and sulfamethoxazole is Bactrim. When these two drugs are combined, they provide a synergistic interaction that is effective against bacterial infections.
Step-by-step explanation:
The medication that combines trimethoprim and sulfamethoxazole is Bactrim. It is a combination of these two drugs that provides a synergistic interaction, making it more effective against bacterial infections. While trimethoprim and sulfamethoxazole individually only inhibit bacterial growth, when combined they become bactericidal.