Trimethoprim hydrochloride

Trimethoprim Hydrochloride is a synthetic antibiotic used primarily in the treatment of bacterial infections. It is often used in combination with sulfamethoxazole, a sulfonamide antibiotic, in a medication commonly referred to as co-trimoxazole or Bactrim.

Chemistry

Trimethoprim hydrochloride is a white, crystalline powder with the chemical formula C14H19ClN4O3. It is soluble in water and has a pKa of 7.3. The compound is a derivative of diaminopyrimidine and is structurally similar to the vitamin folic acid.

Mechanism of Action

Trimethoprim hydrochloride works by inhibiting the action of dihydrofolate reductase, an enzyme involved in the production of tetrahydrofolate. Tetrahydrofolate is necessary for the synthesis of purine, pyrimidine, and certain amino acids. By inhibiting this enzyme, trimethoprim hydrochloride prevents the bacteria from producing these essential compounds, thereby inhibiting their growth and reproduction.

Clinical Use

Trimethoprim hydrochloride is used to treat a variety of bacterial infections, including urinary tract infections, bronchitis, and pneumocystis pneumonia. It is also used as a prophylactic treatment in individuals with a weakened immune system, such as those with HIV/AIDS or those undergoing chemotherapy.

Side Effects

Common side effects of trimethoprim hydrochloride include nausea, vomiting, and rash. In rare cases, it can cause serious side effects such as anemia, leukopenia, and thrombocytopenia.

Drug Interactions

Trimethoprim hydrochloride can interact with other medications, including methotrexate, warfarin, and certain antiepileptic drugs. It is therefore important to inform the healthcare provider of all medications being taken before starting treatment with trimethoprim hydrochloride.

See Also

• Antibiotics
• Bacterial Infections
• Sulfamethoxazole
• Bactrim