Lamivudine 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... 

Drugs that may interact with lamivudine include zalcitabine and trimethoprim/sulfamethoxazole. 

The most common adverse effects of lamivudine seen at doses used to treat HBV are mild they include headache, malaise, fatigue, fever, insomnia, diarrhea, and upper respiratory infections. Elevated alanine aminotransferase (ALT), serum lipase, and creatine kinase may also occur. The safety and efficacy of lamivudine in patients with decompensated liver disease have not been established. Dosage adjustment is required in individuals with renal impairment. Coadministration of trimethoprim-sulfamethoxazole decreases the renal clearance of lamivudine. 

Potential adverse effects are headache, dizziness, insomnia, fatigue, and gastrointestinal discomfort, although these are typically mild. Lamivudine s bioavailability increases when it is -administered with trimethoprim-sulfamethoxazole. Lamivudine and zalcitabine may inhibit the intracellular phosphorylation of one another therefore, their concurrent use should be avoided if possible. Short-term safety of lamivudine has been demonstrated for both mother and infant. 

Lamivudine (3TC) Epivir 150 mg and 300 mg tablets 10 mg/ml solution Trimethoprim/sulfamethoxazole, posaconazole... 

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. 

In a study of 14 HIV-positive patients taking co-trimoxazole 960 mg daily for 5 days, it was found that the AUC of a single 300-mg dose of lamivudine given on day 4 was increased by 43% and the renal clearance was decreased by 35%. The pharmacokinetics of the trimethoprim and the sulfamethoxazole were unaffected. Similarly, in a population pharmacokinetic analysis, the concurrent use of lamivudine and co-trimoxazole was associated with a 31% reduction in the apparent oral clearance of lamivudine, and an estimated 43% increase in steady-state lamivudine levels. The UK manufacturer notes that the interaction is due to trimethoprim, and that sulfamethoxazole did not interact. ... 

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