Trimethoprim

Definition

Trimethoprim is an antibiotic used primarily to treat bacterial infections, particularly in the urogenital and digestive systems. It works by inhibiting bacterial DNA synthesis.

5 Must Know Facts For Your Next Test

1. Trimethoprim specifically inhibits the bacterial enzyme dihydrofolate reductase.
2. It is often combined with sulfamethoxazole to enhance its antibacterial efficacy, forming the drug known as co-trimoxazole.
3. Trimethoprim is effective against a broad spectrum of Gram-positive and Gram-negative bacteria.
4. It is commonly used to treat urinary tract infections (UTIs) and traveler's diarrhea.
5. Bacterial resistance to trimethoprim can occur via mutations in the target enzyme dihydrofolate reductase.

Review Questions

• What mechanism does trimethoprim use to inhibit bacterial growth?
• Why is trimethoprim often combined with sulfamethoxazole?
• Which types of infections are commonly treated with trimethoprim?

Related terms

Sulfamethoxazole:

An antibiotic that inhibits bacterial synthesis of dihydropteroate, often used in combination with trimethoprim.

Co-trimoxazole: A combination of trimethoprim and sulfamethoxazole, used to treat various bacterial infections.

Dihydrofolate Reductase:

The bacterial enzyme targeted by trimethoprim to inhibit DNA synthesis.