Comparative Pharmacology
Head-to-head clinical analysis: PERMAX versus REQUIP XL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PERMAX versus REQUIP XL.
PERMAX vs REQUIP XL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Dopamine D1/D2 receptor agonist; also activates α2-adrenergic and serotonin receptors, reducing prolactin secretion.
Ropinirole is a non-ergoline dopamine agonist with high relative in vitro specificity and full intrinsic activity at the D2 subfamily of dopamine receptors, binding with higher affinity to D3 than to D2 or D4 receptor subtypes. The relevance of D3 receptor binding in Parkinson's disease is unknown.
Initial: 0.05 mg orally once daily; titrate by 0.05-0.1 mg/day every 2-3 days; usual therapeutic dose: 0.1-0.5 mg three times daily; maximum: 1.5 mg three times daily.
Initial: 2 mg orally once daily for weeks 1-2, then titrate as needed; maintenance: 8-24 mg orally once daily.
None Documented
None Documented
Terminal elimination half-life: 27 hours (range 24-30 hours) in healthy adults; significantly prolonged in renal impairment (up to 100+ hours in ESRD), requiring dose adjustment.
Approximately 6 hours (range 4-8 hours) for ropinirole; terminal half-life in elderly or hepatic impairment may be prolonged up to 10-12 hours. Clinically, steady-state achieved within 2 days of dosing.
Renal: ~50% unchanged drug; biliary/fecal: ~40% as metabolites and parent drug; total clearance approximates hepatic blood flow.
Renal: 60% (mainly metabolites, <10% unchanged); fecal/biliary: 20%; total excretion accounts for >80% of dose.
Category C
Category C
Dopamine Agonist
Dopamine Agonist