General

Pronunciation:
tas-i-mel-tee-on

Trade Name(s)

• Hetlioz

Ther. Class.
sedative/hypnotics

Pharm. Class.
melatonin receptor agonists

Indications

Treatment of Non-24–Hour Sleep-Wake Disorder (a circadian rhythm disorder more common in totally blind patients).

Action

Acts as an agonist at melatonin MT₁  and MT₂  receptor sites, which are involved in regulation or circadian rhythm.

Therapeutic Effect(s):

Improved circadian rhythm with improved sleep/wake patterns.

Pharmacokinetics

Absorption: 38% absorbed following oral administration, blood levels are ↑ in female patients.

Distribution: Unknown.

Metabolism and Excretion: Extensively metabolized mostly by CYP1A2 and also CYP3A4, metabolited do not contribute significantly to pharmacological effect. Metabolites are primarily excreted in urine, less than 1% as unchanged drug), 4% excreted in feces.

Half-life: 1.3 hr.

TIME/ACTION PROFILE (establishment of circadian rhythm/sleep cycle)

Contraindication/Precautions

Contraindicated in:

• Severe hepatic impairment.

Use Cautiously in:

• Concurrent use of strong CYP1A2 inducers/inhibitors (may alter drug effects)
• Geri:  ↑ risk of adverse reactions due to ↑ blood levels;
• OB:  May cause fetal harm, use only if potential benefit justifies potential fetal risk;
• Lactation: Use cautiously if breastfeeding;
• Pedi:  Safety and effectiveness not established.

Adverse Reactions/Side Effects

CNS: headache, nightmares/unusual dreams

GI: ↑ liver enzymes

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

• Concurrent use of  strong CYP1A2 inhibitors  including  fluvoxamine  may ↑ drug effects.
• Concurrent use of  strong CYP1A2 inducers  including  rifampin  and  cigarette smoke   may ↓ drug effects.
• Strong CYP3A4 inhibitors, including  ketoconazole  may ↑ blood levels and effects.
•  Alcohol  may ↑ CNS depression.

Route/Dosage

PO (Adults): 20 mg at bedtime, taken at the same time every day.

Availability

Capsules: 20 mg

Assessment

• Assess mental status, sleep patterns, and frequency of daytime naps prior and periodically during therapy.

Lab Test Considerations:

May cause ↑ transaminases.

Potential Diagnoses

• Readiness for enhanced sleep (Indications) 

Implementation

• PO Administer without food before bedtime at the same time each night. Swallow capsule whole; do not open, dissolve, crush, or chew.

Patient/Family Teaching

• Instruct patient to take tasimelteon as directed at the same time each day. If unable to take at approximately the same time on a given night, skip dose and resume following night. After taking, advise patient to limit activity to preparing to go to bed.
• Caution patient tasimelteon can impair performance of activities requiring complete mental alertness. Advise patient to avoid driving and other activities requiring alertness after taking tasimelteon.
• Advise female patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding

Evaluation/Desired Outcomes

Improved circadian rhythm with improved sleep/wake patterns. Due to differences in circadian rhythms, may require daily use for several wks or mo before benefit from tasimelteon is noticeable.