Although prophylaxis for more than one opportunistic infection is emerging as a common clinical practice in patients with advanced HIV disease, little is known about possible adverse drug interactions. The need exists to define pharmacokinetics and pharmacodynamic adverse interactions of the many combination prophylactic regimens that may be prescribed.~In Part A, patients receive sulfamethoxazole-trimethoprim (SMX/TMP) alone for 2 weeks, then in combination with fluconazole, rifabutin, or both drugs, each over 2-week periods in a randomly assigned order. Patients in Part B receive the same regimens except with clarithromycin substituted for rifabutin. In Part C, patients receive dapsone alone for 2 weeks, then in combination with fluconazole, rifabutin, or both drugs in the same manner as in Part A. Part D patients receive the same regimen as those in Part C, except with clarithromycin substituted for rifabutin. Patients are followed every 2 weeks.
To determine the effects of fluconazole and either rifabutin or clarithromycin, alone and in combination, on the pharmacokinetics of first sulfamethoxazole-trimethoprim and then dapsone in HIV-infected patients.~Although prophylaxis for more than one opportunistic infection is emerging as a common clinical practice in patients with advanced HIV disease, little is known about possible adverse drug interactions. The need exists to define pharmacokinetics and pharmacodynamic adverse interactions of the many combination prophylactic regimens that may be prescribed.