Comparative Pharmacology
Head-to-head clinical analysis: MIRAPEX ER versus REQUIP XL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MIRAPEX ER versus REQUIP XL.
MIRAPEX ER vs REQUIP XL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Non-ergot dopamine agonist with high affinity for D2 and D3 receptor subtypes; stimulates dopamine receptors in the striatum.
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.
Oral, start 0.375 mg once daily, titrate weekly by 0.375 mg/dose to 1.5 mg once daily (immediate-release); ER: same total daily dose once 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: 8–12 hours in young healthy adults; prolonged to 16–40 hours in elderly (≥65 years) and up to 30 hours in moderate renal impairment (CrCl 20–50 mL/min).
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 excretion of unchanged drug and metabolites: ~90% in urine (pramipexole: ~70% unchanged; N-desmethyl metabolite: ~20%). Fecal excretion: ~2%. Biliary elimination: minimal.
Renal: 60% (mainly metabolites, <10% unchanged); fecal/biliary: 20%; total excretion accounts for >80% of dose.
Category C
Category C
Dopamine Agonist
Dopamine Agonist