Indinavir Trimethoprim/Sulfamethoxazole

Simultaneous didanosine, folic acid, ganciclovir, lamivudine, nevirapine, pyrazinamide, ranitidine, rifampin, stavudine, sulfamethoxazole, trimethoprim, zidovudine Noninterfering adefovir, amprenavir, delavirdine, efavirenz, fluconazole, indinavir, itraconazole, methadone, nelfinavir, oxazepam, pyrimethamine, rifampin, ritonavir, saquinavir, zalcitabine... 

Items 6-7 A patient with AIDS has a CD4 count of 45/ xL. He is being maintained on a three-drug regimen of indinavir, zalcitabine, and zidovudine. For prophylaxis against opportunistic infections, he is also receiving cidofovir, fluconazole, rifabutin, and trimethoprim-sulfamethoxazole. 

Items 92-93. A 30-year-old hospitalized AIDS patient has a CD4 cell count of 50/ tL. He is being treated with a highly active antiretroviral therapy (HAART) regimen consisting of zidovudine (ZDV), lamivudine (3TC), and indinavir. Other drugs being administered to this patient include acyclovir, clarithromycin, foscamet, rifabutin, and trimethoprim-sulfamethoxazole. 

Because of indinavir s metabolism, a number of drug interactions are possible. Indinavir interacts with rifabutin or ketoconazole, leading to increased or decreased indinavir concentration, respectively, in the blood plasma. Administration of drug combinations of indinavir with antiviral nucleoside analogues, cimetidine, quinidine, trimethoprim/sulfamethoxazole, fluconazole, or isoniazid resulted in an increased activity of indinavir. Indinavir is ... 

A study in 12 healthy subjects given indinavir 400 mg every 6 hours with co-trimoxazole 960 mg every 12 hours found that there was no ehange in the AUC of indinavir, but a small 17% decrease in indinavir trough levels. In addition, there was an 18% increase in the AUC of trimethoprim, and a 5% increase in the AUC of sulfamethoxazole. None of these changes were considered to be clinically important. ... 

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