Триметоприм: Қолданысы, қауіптері мен ескертулер

Antibiotic

Trimethoprim (TMP) is an antibiotic used mainly in the treatment of bladder infections. Other uses include for middle ear infections and travelers' diarrhea. It is taken orally (swallowed by mouth). It works by blocking folate metabolism via dihydrofolate reductase in some bacteria, preventing creation of bacterial DNA and RNA and leading to bacterial cell death. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication.

It is primarily used in the treatment of urinary tract infections, although it may be used against any susceptible aerobic bacterial species. It may also be used to treat and prevent Pneumocystis jirovecii pneumonia. Resistance to trimethoprim is increasing, but it is still a first line antibiotic in many countries.

Can cause thrombocytopenia (low levels of platelets) by lowering folic acid levels; this may also cause megaloblastic anemia. Trimethoprim antagonizes the epithelial sodium channel in the distal tubule, thus acting like amiloride. This can cause increased potassium levels in the body (hyperkalemia). Can compete with creatinine for secretion into the renal tubule. This can cause an artificial rise in the serum creatinine. Use in EHEC infections may lead to an increase in expression of Shiga toxin.

Based on the studies that show that trimethoprim crosses the placenta and can affect folate metabolism, there has been growing evidence of the risk of structural birth defects associated with trimethoprim, especially during the first trimester of pregnancy. The trophoblasts in the early fetus are sensitive to changes in the folate cycle. A 2013 study found a doubling in the risk of miscarriage in women exposed to trimethoprim in the early pregnancy.

Trimethoprim binds to dihydrofolate reductase and inhibits the reduction of dihydrofolic acid (DHF) to tetrahydrofolic acid (THF). Sulfamethoxazole inhibits dihydropteroate synthase, an enzyme involved further upstream in the same pathway. This benefit has been questioned.

Trimethoprim was first used in 1962. In 1972, it was used as a prophylactic treatment for urinary tract infections in Finland. Its name is derived from trimethyloxy pyrimidine.