Ropiniroleinteractions

Inhibitors or inducers of CYP1A2: May alter the clearance of ropinirole; dose adjustment of ropinirole extended-release tablets may be required.

Hormone replacement therapy (HRT): Starting or stopping HRT treatment may require dose adjustment of ropinirole extended-release tablets.

Dopamine antagonists (e.g., neuroleptics metoclopramide): May reduce efficacy of ropinirole extended-release tablets.

7.1 Cytochrome P450 1A2

Inhibitors and Inducers In vitro metabolism studies showed that cytochrome P450 1A2 (CYP1A2) is the major enzyme responsible for the metabolism of ropinirole. There is thus the potential for inducers or inhibitors of this enzyme to alter the clearance of ropinirole. Therefore, if therapy with a drug known to be a potent inducer or inhibitor of CYP1A2 is stopped or started during treatment with ropinirole extended-release tablets, adjustment of the dose of ropinirole extended-release tablets may be required. Coadministration of ciprofloxacin, an inhibitor of CYP1A2, with immediate-release ropinirole increases the AUC and C max of ropinirole. Cigarette smoking is expected to increase the clearance of ropinirole since CYP1A2 is known to be induced by smoking.

7.2 Estrogens

Population pharmacokinetic analysis revealed that higher doses of estrogens (usually associated with hormone replacement therapy) reduced the clearance of ropinirole. Starting or stopping hormone replacement therapy may require adjustment of dosage of ropinirole extended-release tablets.

7.3 Dopamine

Antagonists Because ropinirole is a dopamine agonist, it is possible that dopamine antagonists such as neuroleptics (e.g., phenothiazines, butyrophenones, thioxanthenes) or metoclopramide may reduce the efficacy of ropinirole extended-release tablets.