Comparative Pharmacology
Head-to-head clinical analysis: AMBIEN CR versus PLACIDYL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AMBIEN CR versus PLACIDYL.
AMBIEN CR vs PLACIDYL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
AMBIEN CR's active ingredient is zolpidem, a non-benzodiazepine hypnotic that binds selectively to the benzodiazepine-1 (BZ1) receptor subtype on the GABA-A receptor complex, potentiating GABAergic inhibition and promoting sleep.
Ethchlorvynol is a sedative-hypnotic that depresses the central nervous system at the level of the brainstem and reticular formation, potentiating GABAergic inhibition. Its exact molecular mechanism is not fully defined.
12.5 mg orally once daily immediately before bedtime; lower dose of 6.25 mg may be considered. Not to exceed 12.5 mg per day.
500 mg to 1000 mg orally at bedtime, as a hypnotic. Usual dose is 500 mg to 750 mg. Maximum dose 1000 mg.
None Documented
None Documented
Zolpidem immediate-release: ~2.5 h (range 1.4–3.8 h); modified-release (Ambien CR): ~2.8 h (range 1.6–4.5 h). Clinical note: Half-life increased in hepatic impairment and elderly.
Terminal elimination half-life is approximately 24 hours (range 10-40 hours), with prolonged elimination in hepatic impairment and overdose due to saturation of metabolism.
Primarily renal (80% as metabolites, <5% unchanged), minor fecal (<10%)
Primarily renal excretion of metabolites; less than 1% excreted unchanged. Biliary/fecal elimination accounts for 30-40% of metabolites, with enterohepatic recycling.
Category C
Category C
Sedative-Hypnotic
Sedative-Hypnotic