Drug Interactions between lamivudine / tenofovir disoproxil and trimethoprim
This report displays the potential drug interactions for the following 2 drugs:
- lamivudine/tenofovir disoproxil
- trimethoprim
Interactions between your drugs
trimethoprim lamiVUDine
Applies to: trimethoprim and lamivudine / tenofovir disoproxil
In a study with 14 HIV-positive patients, coadministration of trimethoprim/sulfamethoxazole (trimethoprim/sulfamethoxazole DS once a day for 5 days) and lamivudine (300 mg single dose on day 5) resulted in a mean decrease of 35% in lamivudine renal clearance and a mean increase of 43% in lamivudine area under the plasma concentration-time curve. The mechanism of interaction is thought to be competitive inhibition of tubular secretion by trimethoprim. Lamivudine did not affect the pharmacokinetic profile of trimethoprim/sulfamethoxazole. Given the favorable safety profile of lamivudine, this interaction is unlikely to be of clinical significance. However, patients with renal dysfunction should be monitored carefully and the lamivudine dose adjusted if necessary. In addition, it should be noted that the effect of higher dosages of trimethoprim/sulfamethoxazole on lamivudine pharmacokinetics has not been investigated.
References (3)
- (2001) "Product Information. Epivir (lamivudine)." Glaxo Wellcome
- Moore KHP, Yuen GJ, Raasch RH, Eron JJ, Martin D, Mydlow PK, Hussey EK (1996) "Pharmacokinetics of lamivudine administered alone and with trimethoprim-sulfamethoxazole." Clin Pharmacol Ther, 59, p. 550-8
- Cerner Multum, Inc. "Australian Product Information."
Drug and food interactions
tenofovir food
Applies to: lamivudine / tenofovir disoproxil
Food enhances the oral absorption and bioavailability of tenofovir, the active entity of tenofovir disoproxil fumarate. According to the product labeling, administration of the drug following a high-fat meal increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of tenofovir by approximately 14% and 40%, respectively, compared to administration in the fasting state. However, administration with a light meal did not significantly affect the pharmacokinetics of tenofovir compared to administration in the fasting state. Food delays the time to reach tenofovir Cmax by approximately 1 hour. Tenofovir disoproxil fumarate may be administered without regard to meals.
References (1)
- (2001) "Product Information. Viread (tenofovir)." Gilead Sciences
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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