tasimelteon HETLIOZ
Class: Selective Melatonin Receptor AgonistFDA Indications: Non 24-Hour Sleep-Wake Disorder
Off-Label Use: Shift Work Sleep Disorder (SWSD), Circadian Rhythm Sleep Disorder, Jet Lag
Prescribing
Forms: 20mg capsuleDose Range: 20 mg/day
Starting: 20 mg prior to bedtime, at same time every night. Take without food (when administered with a high-fat meal, Cmax ↓'s 44% lower and Tmax ↓'s 1.75°)
Stopping: No discontinuation symptoms ∴ should be able to discontinue w/o tapering.
Precautions
Side Effects: headache, transaminitis, nightmares, upper respiratory infection, urinary tract infectionPharmacokinetics
t½: 1.3 (0.9-1.7)° TMAX: 0.5-3°Substrate of: 1A2, 3A4
Inhibits: ∅ ; Induces: ∅
Active Metabolites: M9, M11, M12, M13, M14
DDIs
- - caution with other CNS-depressants
- - strong 1A2 and 3A4 inhibitors can ↑ levels, likewise 1A2 and 3A4 inducers can ↓ levels
Misc
- - not a CNS depressant; promotes sleep by regulating the sleep/wake cycle rather than via CNS-depression
- - lacks strong sleep-onset induction that the benzos and nonbenzos confer
- - melatoninergic agonists do not cause next-day hangover and withdrawal effects
- - no tolerance or abuse potential
- - exhibits linear pharmacokinetics
- - affinity of tasimelteon for MT2 is 4-fold higher than its affinity for MT1 (theoretically, it's the stimulation of MT2 that mediates the phase shifting effect of melatonin, i.e. "resetting the clock")
- - 57% greater MT2 binding affinity than ramelteon
- - cost prohibitive: > $7,000/mo
Special Populations
Category C—No reports describing the use of tasimelteon in human pregnancy have been located. The animal data suggest low risk but the absence of human pregnancy experience prevents a better assessment of the embryo-fetal risk.
No reports describing the use of tasimelteon during human lactation have been located. The molecular weight (about 245) and t½ of tasimelteon (1.3°) suggest that tasimelteon and metabolites will be excreted into breast milk, but the high plasma protein binding (90%) should limit the amount in milk.
The risk of adverse reactions may be greater in elderly (>65 years) patients than younger patients because exposure to tasimelteon is increased by approximately 2-fold compared with younger patients.
No dose adjustment is necessary for patients with renal impairment.
Dose adjustment is not necessary in patients with mild or moderate hepatic impairment. Has not been studied in patients with severe hepatic impairment (Child-Pugh Class C). Therefore, not recommended for use in patients with severe hepatic impairment.
References
Package InsertStahl's Essential Psychopharmacology 4th Ed
Comparative Review Of Approved Melatonin Agonists For The Treatment Of Circadian Rhythm SleepâWake Disorders
Pharmacokinetics Of The Dual Melatonin Receptor Agonist Tasimelteon In Subjects With Hepatic Or Renal Impairment
MT1 And MT2 Melatonin Receptors: A Therapeutic Perspective
Drugs In Pregnancy And Lactation 11th Ed