| Starting dose | Usual effective dose | Metabolism | Common side effects and precautions* | |
| Melatonin | 3 mg orally at bedtime (NOTE: Dose for treatment of adults with primary insomnia approved in some countries is 2 mg one to two hours before bedtime) | 6 to 18 mg orally at bedtime | Hepatic by CYP1A1 and 1A2; avoid or use with caution in patients with hepatic impairment Inhibitors of CYP1A (eg, ciprofloxacin, fluvoxamine, hormonal contraceptives, estrogen replacement therapy, methoxsalen) can increase melatonin concentrations Inducers of CYP1A (eg carbamazepine, rifampin, cigarette smoke) can reduce melatonin concentrations | Similar to placebo in short-term use at physiologic doses¶ Daytime sleepiness and impairment of attention, memory, and coordination seen with higher doses and/or in combination with other sedating medicines Effects in long-term use >13 weeks are not established Unlicensed, nonprescription products can vary widely in oral bioavailability due to differences in the type of preparation and additives used¶ |
| Clonazepam | 0.25 to 0.5 mg orally at bedtime | 0.5 to 1 mg orally at bedtime | Hepatic by CYP3A4; use with caution in patients with hepatic impairment Prolonged half-life (18 to 50 hours) | Morning sleepiness, confusion, dizziness, ataxia, amnesia Avoid or use caution in patients with dementia, gait disorders, or obstructive sleep apnea |
