Drug Interaction Report

MONITOR: Coadministration with inhibitors of CYP450 2D6 may increase the plasma concentrations of topical sofpironium, which has been shown to be partially metabolized by the isoenzyme. In a pharmacokinetic study in patients with primary axillary hyperhidrosis, sofpironium systemic exposure (AUC) and peak plasma concentration (Cmax) increased approximately 2-fold following concomitant use with the potent CYP450 2D6 inhibitor paroxetine at a 20 mg oral dose. Clinical data for sofpironium use in combination with other less potent CYP450 2D6 inhibitors are not available.

MANAGEMENT: Caution is advised when sofpironium topical is used concurrently with CYP450 2D6 inhibitors. Patients should be more closely monitored for adverse effects such as blurred vision, urinary retention, difficulty controlling body temperature in warm environments, and dry mouth.

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.