Comparative Pharmacology
Head-to-head clinical analysis: CYCLOSET versus REQUIP XL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLOSET versus REQUIP XL.
CYCLOSET vs REQUIP XL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Cycloset (bromocriptine mesylate) is a dopamine D2 receptor agonist. It improves glycemic control in type 2 diabetes by resetting hypothalamic circadian rhythms, thereby reducing hepatic glucose production and increasing insulin sensitivity. It also suppresses the release of very low-density lipoprotein from the liver.
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.
1.6 mg to 2.4 mg administered orally once daily at bedtime. Titrate by 0.8 mg every 2 weeks based on glycemic response and tolerability.
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 is 4–6 hours in patients with normal renal function; clinically, steady-state is reached within 24 hours.
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: ~90% (30% unchanged, rest as inactive metabolites); fecal: ~10%.
Renal: 60% (mainly metabolites, <10% unchanged); fecal/biliary: 20%; total excretion accounts for >80% of dose.
Category C
Category C
Dopamine Agonist / Antidiabetic
Dopamine Agonist