Drug Interactions between Ritalin and tenofovir disoproxil

GENERALLY AVOID: Alcohol may exacerbate the adverse central nervous system effects of psychoactive drugs, including methylphenidate.

GENERALLY AVOID: Consumption of alcohol while taking certain sustained-release formulations of methylphenidate may cause rapid release of the drug, resulting in increased systemic levels of methylphenidate. In vitro studies have been conducted using Metadate CD 60 mg and Ritalin LA 40 mg capsules, as well as Concerta 18 mg tablet. At an alcohol concentration of 40%, an increase in the release rate of methylphenidate was observed in the first hour for Metadate CD and Ritalin LA, resulting in 84% and 98% of the methylphenidate being released, respectively. In contrast, there was no increased release of methylphenidate in the first hour for Concerta. These results are considered to be representative of the other available strengths of the corresponding product.

MANAGEMENT: Patients treated with methylphenidate should be advised to avoid alcohol or medications that contain alcohol.

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.