Drug Interaction Report

MONITOR: Coadministration with cobicistat may increase the plasma concentrations of drugs that are substrates of the CYP450 3A4 or 2D6 isoenzymes and/or P-glycoprotein (P-gp) efflux transporter.

MANAGEMENT: Caution is advised if cobicistat is used concomitantly with medications that undergo metabolism primarily by CYP450 3A4 and/or 2D6 or are substrates of P-glycoprotein, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever cobicistat is added to or withdrawn from therapy.

GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.

MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.