Drug Reference
Tasimelteon
Melatonin receptor agonists
Rx onlyControlled · controlled substance
Fact box
- Therapeutic class
- Melatonin receptor agonists
- Action class
- Melatonin Receptor Agonist
- Mechanism
- Melatonin Receptor Agonists
- Habit forming
- Yes — controlled substance
- Availability
- Prescription (Rx)
Brand names
Hetlioz
Available as
20 MG · Oral Capsule4 MG/ML · Oral Suspension
FDA label sections are from openFDA and may not reflect the most recent labeling — confirm against the current DailyMed label.
Uses
1 INDICATIONS AND USAGE Tasimelteon capsules are a melatonin receptor agonist. Tasimelteon capsules are indicated for the treatment of Non 24-Hour Sleep-Wake Disorder (Non-24) in adults ( 1 ) 1.1 Non-24-Hour Sleep-Wake Disorder (Non-24) Tasimelteon capsules are indicated for the treatment of Non-24 in adults.
How it works
12.1 Mechanism of Action The mechanism by which tasimelteon exerts its therapeutic effect in patients with Non-24 is unclear. However, tasimelteon is an agonist at melatonin MT 1 and MT 2 receptors which are thought to be involved in the control of circadian rhythms.
How to use / dosing
2 DOSAGE AND ADMINISTRATION Indicated Population Dosage Form Body Weight Recommended Dosage Non-24 ( 2.2 ) Adults Capsules Not applicable 20 mg one hour prior to bedtime Tasimelteon capsules and tasimelteon oral suspension are not substitutable ( 2.1 ) Administer at the same time every night ( 2.2 ) Take without food ( 2.4 ) 2.1 Non-Interchangeability between Tasimelteon Capsules and Tasimelteon Oral Suspension Tasimelteon capsules and tasimelteon oral suspension are not substitutable [see Clinical Pharmacology ( 12.3 )]. 2.2 Recommended Dosage for Tasimelteon Capsules for Non-24 Adults The recommended dosage of tasimelteon capsules in adults is 20 mg one hour before bedtime, at the same time every night. Because of individual differences in circadian rhythms, drug effect may not occur for weeks or months. 2.4 Important Administration Information Administer tasimelteon capsules without food [see Clinical Pharmacology ( 12.3 )]. If a patient is unable to take tasimelteon capsules at approximately the same time on a given night, they should skip that dose and take the next dose as scheduled.
Side effects
6 ADVERSE REACTIONS The most common adverse reactions (incidence >5% and at least twice as high on tasimelteon than on placebo) were headache, increased alanine aminotransferase, nightmares or unusual dreams, and upper respiratory or urinary tract infection ( 6.1) To report SUSPECTED ADVERSE REACTIONS, contact Apotex Corp. at 1-800-706-5575 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. More than 2080 subjects have been treated with at least one dose of tasimelteon, of which more than 380 have been treated for > 26 weeks and more than 170 have been treated for > 1 year. Non-24-Hour Sleep-Wake Disorder (Non-24) A 26-week, parallel-arm placebo-controlled study (Study 1) evaluated tasimelteon (n=42) compared to placebo (n=42) in patients with Non-24. A randomized-withdrawal, placebo-controlled study of 8 weeks duration (Study 2) also evaluated tasimelteon (n=10), compared to placebo (n=10), in patients with Non-24. In placebo-controlled studies, 6% of patients exposed to tasimelteon discontinued treatment due to an adverse event, compared with 4% of patients who received placebo. Table 2 shows the incidence of adverse reactions from Study 1. Table 2: Adverse Reactions in Study 1 Tasimelteon N=42 Placebo N=42 Headache 17 % 7 % Alanine aminotransferase increased 10 % 5 % Nightmare/abnormal dreams 10 % 0 % Upper respiratory tract infection 7 % 0 % Urinary tract infection 7 % 2 % *Adverse reactions with an incidence > 5% and at least twice as high on tasimelteon than on placebo are displayed.
Safety advice
Conservative summary derived from FDA labeling — defaults to “consult your doctor” unless the label is explicit. Not a substitute for your clinician’s advice.
PregnancyUnsafe
8.1 Pregnancy Risk Summary Available postmarketing case reports with tasimelteon use in pregnant women are not sufficient to evaluate drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. In pregnant rats, no embryofetal developmental toxicity was observed at exposures of 50 mg/kg/day, or up to 24 times higher than the human exposure at the maximum recommended human dose (MRHD) (see Data). The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data In pregnant rats administered tasimelteon at oral doses of 5, 50, or 500 mg/kg/day during the period of organogenesis, there were no effects on embryofetal development. The highest dose tested is approximately 240 times the MRHD of 20 mg/day, based on mg/m 2 body surface area. In pregnant rabbits administered tasimelteon at oral doses of 5, 30, or 200 mg/kg/day during the period of organogenesis, embryolethality and embryofetal toxicity (reduced fetal body weight and delayed ossification) were observed at the highest dose tested. The highest dose is approximately 200 times the MRHD. Oral administration of tasimelteon at 50, 150, or 450 mg/kg/day to rats throughout organogenesis resulted in persistent reductions in body weight, delayed sexual maturation, and physical development, and neurobehavioral impairment in offspring at the highest dose tested which is approximately 220 times the MRHD based on mg/m 2 body surface area. Reduced body weight in offspring was also observed at the mid-dose. The no effect dose (NOEL), (50 mg/kg/day) is approximately 25 times the MRHD based on mg/m 2 body surface area.
BreastfeedingConsult your doctor
8.2 Lactation Risk Summary There are no data on the presence of tasimelteon or its metabolites in human or animal milk, the effects on the breastfed infant, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for tasimelteon and any potential adverse effects on the breastfed infant from tasimelteon or from the underlying maternal condition.
AlcoholNo information
No specific information in the FDA label.
DrivingNo information
No specific information in the FDA label.
KidneyNo information
No specific information in the FDA label.
LiverCaution
…8 USE IN SPECIFIC POPULATIONS Hepatic impairment: Tasimelteon has not been studied in patients with severe hepatic impairment and is not recommended in these patients ( 8.6 ) 8.1 Pregnancy Risk Summary Available postmarketing…
Warnings & precautions
5 WARNINGS AND PRECAUTIONS May cause somnolence: After taking tasimelteon capsules, patients should limit their activity to preparing for going to bed, because tasimelteon capsules can impair the performance of activities requiring complete mental alertness ( 5.1 ) 5.1 Somnolence After taking tasimelteon capsules, patients should limit their activity to preparing for going to bed. Tasimelteon capsules can potentially impair the performance of activities requiring complete mental alertness.
Contraindications
4 CONTRAINDICATIONS None. None ( 4 )
Pediatric use
8.4 Pediatric Use Safety and effectiveness of tasimelteon capsules for the treatment of Non-24 in pediatric patients have not been established. Juvenile Animal Toxicity Data Juvenile rats received oral doses of tasimelteon at 50, 150, or 450 mg/kg from weaning (day 21) through adulthood (day 90). These doses are approximately 12 to 108 times the maximum recommended human dose (MRHD) of 20 mg based on a mg/m 2 body surface area. Toxicity was observed mainly at the highest dose and included mortality (females only), tremors, unsteady gait, decrease in growth and development compared to controls. The former reflected as decreases in bone growth, bone mineral content, bone ossification, and a delay in attainment of sexual maturation. Tasimelteon had no effect on fertility, reproduction, or learning and memory. The No Observed Adverse Effect Level (NOAEL) is 150 mg/kg/day, which is approximately 178 times the MRHD based on AUC.
⚑ About half of pediatric medication use is off-label and not described in FDA labels — absence of pediatric information does not mean a medicine is unused or unsafe in children. Confirm with your clinician.
Interactions (label text — not an interaction checker)
7 DRUG INTERACTIONS Strong CYP1A2 inhibitors (e.g., fluvoxamine): Avoid use of tasimelteon in combination with strong CYP1A2 inhibitors because of increased exposure ( 7.1 , 12.3 ) Strong CYP3A4 inducers (e.g., rifampin): Avoid use of tasimelteon in combination with rifampin or other CYP3A4 inducers, because of decreased exposure ( 7.2 , 12.3 ) 7.1 Strong CYP1A2 Inhibitors (e.g., fluvoxamine) Avoid use of tasimelteon in combination with fluvoxamine or other strong CYP1A2 inhibitors because of a potentially large increase in tasimelteon exposure and greater risk of adverse reactions [see Clinical Pharmacology ( 12.3 )]. 7.2 Strong CYP3A4 Inducers (e.g., rifampin) Avoid use of tasimelteon in combination with rifampin or other CYP3A4 inducers because of a potentially large decrease in tasimelteon exposure with reduced efficacy [see Clinical Pharmacology ( 12.3 )]. 7.3 Beta-Adrenergic Receptor Antagonists (e.g., acebutolol, metoprolol) Beta-adrenergic receptor antagonists have been shown to reduce the production of melatonin via specific inhibition of beta-1 adrenergic receptors. Nighttime administration of beta-adrenergic receptor antagonists may reduce the efficacy of tasimelteon.
Overdose
10 OVERDOSAGE There is limited premarketing clinical experience with the effects of an overdosage of tasimelteon. As with the management of any overdose, general symptomatic and supportive measures should be used, along with immediate gastric lavage where appropriate. Intravenous fluids should be administered as needed. Respiration, pulse, blood pressure, and other appropriate vital signs should be monitored, and general supportive measures employed. While hemodialysis was effective at clearing tasimelteon and the majority of its major metabolites in patients with renal impairment, it is not known if hemodialysis will effectively reduce exposure in the case of overdose. As with the management of any overdose, the possibility of multiple drug ingestion should be considered. Contact a poison control center for current information on the management of overdose.
Current FDA labels (DailyMed)
Authoritative sources
Reference only — not clinical advice. Verify against current FDA labeling and consult a licensed provider. About half of pediatric drug use is off-label and is not reflected in FDA labels; absence of pediatric information does not mean a medicine is unused or unsafe in children.