Drug Interaction Report

MONITOR: Coadministration with estrogen-containing drugs may increase the plasma concentrations of ropinirole. Data from a population pharmacokinetic study revealed that estrogens, mainly ethinyl estradiol at 0.6 to 3 mg over a 4-month to 23-year period, reduced the oral clearance of ropinirole by up to 36% in 16 patients. The mechanism of interaction has not been described.

MANAGEMENT: Dosage adjustment for ropinirole should not be necessary in patients already on estrogen therapy because patients must be carefully titrated to tolerance or adequate effect. However, if estrogen therapy is initiated or discontinued during treatment with ropinirole, then patients should be monitored for altered ropinirole effects and the dosage adjusted as necessary. Patients and/or caregivers should be advised to notify the doctor if they experience agitation, impulse control or compulsive behaviors, orthostasis, sedation, confusion, hallucinations, and/or increased dyskinesia, flushing, dry mouth, sweating, or heart rate.

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.