Gastrointestinal damage induced by cytostatic treatment does not affect the bioavailability of co-trimoxazole

Twelve lymphoma patients received prophylaxis with co-trimoxazole during cy tostatic treatment according to the MACOP-B regimen with cyclophosphamide, doxorubicin, vincristine, methotrexate, bleomycin, folinic acid and prednis one. Gastrointestinal mucosal damage from cytostatic treatment was estimate d by WHO toxicity scores. No correlation was found between the degree of ga strointestinal damage and the presumed bioavailability of co-trimoxazole as estimated from serum levels of trimethoprim and sulphamethoxazole. The ser um concentrations were above the minimum inhibitory concentration for Esche richia coli, Staphylococcus aureus and coagulase-negative staphylococci irr espective of the deg ree of toxicity. There is no apparent reason to change the dosing regimen of prophylactic co-trimoxazole when there is clinical e vidence of damage to the gastrointestinal mucosa induced by chemotherapy. C opyright (C) 1999 S. Karger AG, Basel.