Leukopenia, trimethoprim causing

Trimethoprim produces the predictable adverse effects of an antifolate drug, especially megaloblastic anemia, leukopenia, and granulocytopenia. The combination trimethoprim-sulfamethoxazole may cause all of the untoward reactions associated with sulfonamides. Nausea and vomiting, drug fever, vasculitis, renal damage, and central nervous system disturbances occasionally occur also. Patients with AIDS and pneumocystis pneumonia have a particularly high frequency of untoward reactions to trimethoprim-sulfamethoxazole, especially fever, rashes, leukopenia, diarrhea, elevations of hepatic aminotransferases, hyperkalemia, and hyponatremia. 

Severe adverse drug reactions with trimethoprim and co-trimoxazole are rare (12-14). This also applies to children (15). The adverse effects of co-trimoxazole correspond to those expected from a sulfonamide (16). In HIV-infected patients, adverse effects of co-trimox-azole are more frequent and more severe (17-19). Hematological disturbances due to co-trimoxazole include mild anemia, leukopenia, and thrombocytopenia, which may be due to folic acid antagonism. Serious metabolic disturbances that are associated with trimethoprim include hyperkalemia and metabolic acidosis. Trimethoprim can cause hypersensitivity reactions. However, with co-trimoxazole, the sulfonamide is generally believed to be more allergenic (12). Generalized skin reactions predominate. Other effects, such as anaphylactic shock, are extremely rare (20-22). Carcinogenicity due to trimethoprim or co-trimoxazole has not been reported. 

Trimethoprim (and pyrimethamine) may cause anemia, leukopenia, and thrombocytopenia, most commonly in debilitated or immunosuppressed patients. Hematotoxicity, drug fever, rashes, and severe GI distress are problematic in patients with AIDS. 

The incidence of side effects is higli Lower-dose oral therapy with 800 mg sulfamethoxazole plus 160 mg trimethoprim (given twice daily) has been used successjully in AIDS patients with less severe pneumonia (P02 >70 mm Hg). Prophylaxis with 800 mg sulfamethoxazole and 160 mg trimethoprim once daily or three times a week is effective in preventing pneumonia caused by this organism in patients with AIDS. Adverse reactions are less frequent with the lower prophylactic doses of trimethoprimr-sulfamethoxazole. The most common problems are rash, fever, leukopenia, and hepatitis. 

F. Toxicity of Trimethoprim Trimethoprim may cause the predictable adverse effects of an antifolate dmg, including megaloblastic anemia, leukopenia, and granulocytopenia. These effects are usually ameliorated by supplementary folinic acid. The combination of trimethoprim-sulfamethoxazole may cause any of the adverse effects associated with the sulfonamides. AIDS patients given TMP-SMZ have a high incidence of adverse effects, including fever, rashes, leukopenia, and diarrhea. 

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