Hetlioz

Overdose

There is limited premarketing clinical experience with the effects of an overdosage of HETLIOZ.

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 HETLIOZ 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.

Contraindications

None.

Undesirable effects

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.

A total of 1346 subjects were treated with at least one dose of HETLIOZ, of which 139 were treated for > 26 weeks and 93 were treated for > 1 year.

A 26-week, parallel-arm placebo-controlled study (Study 1) evaluated HETLIOZ (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 HETLIOZ (n=10), compared to placebo (n=10), in patients with Non-24.

In placebo-controlled studies, 6% of patients exposed to HETLIOZ discontinued treatment due to an adverse event, compared with 4% of patients who received placebo.

Table 1 shows the incidence of adverse reactions from Study 1.

Table 1: Adverse Reactions in Study 1

Therapeutic indications

HETLIOZ is indicated for the treatment of Non-24-Hour Sleep-Wake Disorder (Non-24).

Pharmacodynamic properties

HETLIOZ is an agonist at MT1 and MT2 receptors. HETLIOZ exhibits a greater affinity for the MT2 as compared to the MT1 receptor. The most abundant metabolites of HETLIOZ have less than one-tenth of the binding affinity of the parent molecule for both the MT1 and MT2 receptors.

Pharmacokinetic properties

The pharmacokinetics of HETLIOZ is linear over doses ranging from 3 to 300 mg (0.15 to 15 times the recommended daily dosage). The pharmacokinetics of HETLIOZ and its metabolites did not change with repeated daily dosing.

The absolute oral bioavailability is 38.3%. The peak concentration (Tmax) of tasimelteon occurred approximately 0.5 to 3 hours after fasted oral administration.

When administered with a high-fat meal, the Cmax of tasimelteon was 44% lower than when given in a fasted state, and the median Tmax was delayed by approximately 1.75 hours. Therefore, HETLIOZ should be taken without food.

The apparent oral volume of distribution of tasimelteon at steady state in young healthy subjects is approximately 59 -126 L. At therapeutic concentrations, tasimelteon is about 90% bound to proteins.

Tasimelteon is extensively metabolized. Metabolism of tasimelteon consists primarily of oxidation at multiple sites and oxidative dealkylation resulting in opening of the dihydrofuran ring followed by further oxidation to give a carboxylic acid. CYP1A2 and CYP3A4 are the major isozymes involved in the metabolism of tasimelteon.

Phenolic glucuronidation is the major phase II metabolic route.

Major metabolites had 13-fold or less activity at melatonin receptors compared to tasimelteon.

Following oral administration of radiolabeled tasimelteon, 80% of total radioactivity was excreted in urine and approximately 4% in feces, resulting in a mean recovery of 84%. Less than 1% of the dose was excreted in urine as the parent compound.

The observed mean elimination half-life for tasimelteon is 1.3 ± 0.4 hours. The mean terminal elimination half-life ± standard deviation of the main metabolites ranges from 1.3 ± 0.5 to 3.7 ± 2.2.

Repeated once daily dosing with HETLIOZ does not result in changes in pharmacokinetic parameters or significant accumulation of tasimelteon.

Date of revision of the text

Name of the medicinal product

Fertility, pregnancy and lactation

There are no adequate and well-controlled studies of HETLIOZ in pregnant women. In animal studies, administration of tasimelteon during pregnancy resulted in developmental toxicity (embryofetal mortality, neurobehavioral impairment, and decreased growth and development in offspring) at doses greater than those used clinically. HETLIOZ should be used during pregnancy only if the potential benefit justifies the potential risks.

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 recommended human dose (RHD) of 20 mg/day, on a mg/m² basis.

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 not associated with adverse effects (30 mg/kg/day) is approximately 30 times the RHD on a mg/m² basis.

Oral administration of tasimelteon (50, 150, or 450 mg/kg/day) to rats throughout organogenesis and lactation resulted in persistent reductions in body weight, delayed sexual maturation and physical development, and neurobehavioral impairment in offspring at the highest dose tested. Reduced body weight in offspring was also observed at the mid-dose. The no effect dose (50 mg/kg/day) is approximately 25 times the RHD on a mg/m² basis.

Qualitative and quantitative composition

Capsules: 20 mg size 1 dark blue opaque, hard gelatin capsules printed with “VANDA 20 mg” in white.

HETLIOZ 20 mg capsules are available as size 1, dark blue opaque, hard gelatin capsules printed with “VANDA 20 mg” in white, containing 20 mg of tasimelteon per capsule.

NDC 43068-220-01 Bottles of 30

Store HETLIOZ 20 mg capsules at controlled room temperature, 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Protect HETLIOZ 20 mg capsules from exposure to light and moisture.

Distributed by: Vanda Pharmaceuticals Inc. Washington, D.C. 20037 USA www.hetlioz.com. Revised: Dec 2014

Special warnings and precautions for use

Included as part of the PRECAUTIONS section.

After taking HETLIOZ, patients should limit their activity to preparing for going to bed. HETLIOZ can potentially impair the performance of activities requiring complete mental alertness.

Tasimelteon was administered orally for up to two years to mice (30, 100, and 300 mg/kg/day) and rats (20, 100, and 250 mg/kg/day). No evidence of carcinogenic potential was observed in mice; the highest dose tested is approximately 75 times the recommended human dose (RHD) of 20 mg/day, on a mg/m² basis. In rats, the incidence of liver tumors was increased in males (adenoma and carcinoma) and females (adenoma) at 100 and 250 mg/kg/day; the incidence of tumors of the uterus (endometrial adenocarcinoma) and uterus and cervix (squamous cell carcinoma) were increased at 250 mg/kg/day. There was no increase in tumors at the lowest dose tested in rats, which is approximately 10 times the RHD on a mg/m² basis.

Tasimelteon was negative in an in vitro bacterial reverse mutation (Ames) assay, an in vitro cytogenetics assay in primary human lymphocytes, and an in vivo micronucleus assay in rats.

When male and female rats were given tasimelteon at oral doses of 5, 50, or 500 mg/kg/day prior to and throughout mating and continuing in females to gestation day 7, estrus cycle disruption and decreased fertility were observed at all but the lowest dose tested. The no-effect dose for effects on female reproduction (5 mg/kg/day) is approximately 2 times the RHD on a mg/m² basis.

There are no adequate and well-controlled studies of HETLIOZ in pregnant women. In animal studies, administration of tasimelteon during pregnancy resulted in developmental toxicity (embryofetal mortality, neurobehavioral impairment, and decreased growth and development in offspring) at doses greater than those used clinically. HETLIOZ should be used during pregnancy only if the potential benefit justifies the potential risks.

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 recommended human dose (RHD) of 20 mg/day, on a mg/m² basis.

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 not associated with adverse effects (30 mg/kg/day) is approximately 30 times the RHD on a mg/m² basis.

Oral administration of tasimelteon (50, 150, or 450 mg/kg/day) to rats throughout organogenesis and lactation resulted in persistent reductions in body weight, delayed sexual maturation and physical development, and neurobehavioral impairment in offspring at the highest dose tested. Reduced body weight in offspring was also observed at the mid-dose. The no effect dose (50 mg/kg/day) is approximately 25 times the RHD on a mg/m² basis.

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when HETLIOZ is administered to a nursing woman.

Safety and effectiveness in pediatric patients have not been established.

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.

Dose adjustment is not necessary in patients with mild or moderate hepatic impairment. HETLIOZ has not been studied in patients with severe hepatic impairment (Child-Pugh Class C). Therefore, HETLIOZ is not recommended for use in patients with severe hepatic impairment.

Smoking causes induction of CYP1A2 levels. The exposure of tasimelteon in smokers was lower than in non-smokers and therefore the efficacy of HETLIOZ may be reduced in smokers.

Dosage (Posology) and method of administration

The recommended dosage of HETLIOZ is 20 mg per day taken before bedtime, at the same time every night.

Because of individual differences in circadian rhythms, drug effect may not occur for weeks or months.

HETLIOZ should be taken without food.

Interaction with other medicinal products and other forms of interaction

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.

A total of 1346 subjects were treated with at least one dose of HETLIOZ, of which 139 were treated for > 26 weeks and 93 were treated for > 1 year.

A 26-week, parallel-arm placebo-controlled study (Study 1) evaluated HETLIOZ (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 HETLIOZ (n=10), compared to placebo (n=10), in patients with Non-24.

In placebo-controlled studies, 6% of patients exposed to HETLIOZ discontinued treatment due to an adverse event, compared with 4% of patients who received placebo.

Table 1 shows the incidence of adverse reactions from Study 1.

Table 1: Adverse Reactions in Study 1

Avoid use of HETLIOZ in combination with fluvoxamine or other strong CYP1A2 inhibitors because of a potentially large increase in tasimelteon exposure and greater risk of adverse reactions.

Avoid use of HETLIOZ in combination with rifampin or other CYP3A4 inducers because of a potentially large decrease in tasimelteon exposure with reduced efficacy.

Tasimelteon is not a controlled substance under the Controlled Substances Act.

Tasimelteon did not produce any abuse-related signals in animal behavioral studies. Rats did not self-administer tasimelteon, suggesting that the drug does not have rewarding properties. There were also no signs or symptoms indicative of abuse potential in clinical studies with HETLIOZ.

Discontinuation of HETLIOZ in humans following chronic administration did not produce withdrawal signs. HETLIOZ does not appear to produce physical dependence.