Ramelteon

12.1 Mechanism of Action Ramelteon is a melatonin receptor agonist with both high affinity for melatonin MT 1 and MT 2 receptors and relative selectivity over the MT 3 receptor. The activity of ramelteon at the MT 1 and MT 2 receptors is believed to contribute to its sleep- promoting properties, as these receptors, acted upon by endogenous melatonin, are thought to be involved in the maintenance of the circadian rhythm underlying the normal sleep-wake cycle. Ramelteon has no appreciable affinity for the GABA receptor complex or for receptors that bind neuropeptides, cytokines, serotonin, dopamine, noradrenaline, acetylcholine, and opiates. Ramelteon also does not interfere with the activity of a number of selected enzymes in a standard panel. The major metabolite of ramelteon, M-II, is pharmacologically active and has approximately one tenth and one fifth the binding affinity of the parent molecule for the human MT 1 and MT 2 receptors, respectively. However, M-II circulates at higher concentrations than the parent producing 20- to 100-fold greater mean systemic exposure when compared to ramelteon. Similar to ramelteon, M-II does not interfere with the activity of a number of endogenous enzymes. All other known metabolites of ramelteon are inactive.

1 INDICATIONS AND USAGE Ramelteon tablets are indicated for the treatment of insomnia characterized by difficulty with sleep onset. The clinical trials performed in support of efficacy were up to six months in duration. The final formal assessments of sleep latency were performed after two days of treatment during the crossover study (elderly only), at five weeks in the six week studies (adults and elderly), and at the end of the six month study (adults and elderly) [see Clinical Studies (14) ] . Ramelteon tablets are indicated for the treatment of insomnia characterized by difficulty with sleep onset. ( 1 )

2 DOSAGE AND ADMINISTRATION Adult dose: 8 mg taken within 30 minutes of going to bed. ( 2.1 ) Should not be taken with or immediately after a high-fat meal. ( 2.1 ) Total daily dose should not exceed 8 mg. ( 2.1 ) 2.1 Dosage in Adults The recommended dose of ramelteon tablets are 8 mg taken within 30 minutes of going to bed. It is recommended that ramelteon tablets not be taken with or immediately after a high-fat meal. The total ramelteon tablets dose should not exceed 8 mg per day. 2.2 Dosing in Patients with Hepatic Impairment Ramelteon tablets are not recommended in patients with severe hepatic impairment. Ramelteon tablets should be used with caution in patients with moderate hepatic impairment [see Warnings and Precautions (5.6) , Clinical Pharmacology (12.4) ] . 2.3 Administration with Other Medications Ramelteon tablets should not be used in combination with fluvoxamine. Ramelteon tablets should be used with caution in patients taking other CYP1A2 inhibiting drugs [see Drug Interactions (7) , Clinical Pharmacology (12.5) ].

6 ADVERSE REACTIONS The following serious adverse reactions are discussed in greater detail in other sections: Severe anaphylactic and anaphylactoid reactions [see Warnings and Precautions (5.1) ] Abnormal thinking, behavior changes, and complex behaviors [see Warnings and Precautions (5.3) ] CNS effects [see Warnings and Precautions (5.4) ] Most common adverse reactions (≥3% and more common than with placebo) are: somnolence, dizziness, fatigue, nausea, and exacerbated insomnia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Aurobindo Pharma USA, Inc. at 1-866-850-2876 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Adverse Reactions Resulting in Discontinuation of Treatment The data described in this section reflect exposure to ramelteon in 5373 subjects, including 722 exposed for six months or longer, and 448 subjects for one year. Six percent of the 5373 individual subjects exposed to ramelteon in clinical studies discontinued treatment owing to an adverse event, compared with 2% of the 2279 subjects receiving placebo. The most frequent adverse events leading to discontinuation in subjects receiving ramelteon were somnolence, dizziness, nausea, fatigue, headache, and insomnia; all of which occurred in 1% of the patients or less. Ramelteon Most Commonly Observed Adverse Events Table 1 displays the incidence of adverse events reported by the 2861 patients with chronic insomnia who participated in placebo-controlled trials of ramelteon. 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 clinical trials of other drugs, and may not reflect the rates observed in practice. The adverse reaction information from clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and for approximating rates. Table 1. Incidence (% of subjects) of Treatment-Emergent Adverse Events MedDRA Preferred Term Placebo (n=1456) Ramelteon 8 mg (n=1405) Somnolence 2% 3% Fatigue 2% 3% Dizziness 3% 4% Nausea 2% 3% Insomnia exacerbated 2% 3%

7 DRUG INTERACTIONS Rifampin (strong CYP enzyme inducer): Decreases exposure to and effects of ramelteon. ( 7.1 ) Ketoconazole (strong CYP3A4 inhibitor): Increases AUC for ramelteon; administer with caution. ( 7.1 ) Fluconazole (strong CYP2C9 inhibitor): Increases systemic exposure of ramelteon; administer with caution. ( 7.1 ) Donepezil: Increases systemic exposure of ramelteon; patients should be closely monitored when ramelteon is coadministered with donepezil. ( 7.1 ) Doxepin: Increases systemic exposure of ramelteon; patients should be closely monitored when ramelteon is coadministered with doxepin. ( 7.1 ) Alcohol: Causes additive psychomotor impairment; should not be used in combination. ( 7.2 ) 7.1 Effects of Other Drugs on Ramelteon Fluvoxamine (strong CYP1A2 inhibitor) AUC 0-inf for ramelteon increased approximately 190-fold, and the C max increased approximately 70- fold upon coadministration of fluvoxamine and ramelteon, compared to ramelteon administered alone. Ramelteon should not be used in combination with fluvoxamine [see Contraindications (4), Clinical Pharmacology (12.5) ] . Other less strong CYP1A2 inhibitors have not been adequately studied. Ramelteon should be administered with caution to patients taking less strong CYP1A2 inhibitors. Rifampin (strong CYP enzyme inducer) Administration of multiple doses of rifampin resulted in a mean decrease of approximately 80% in total exposure to ramelteon and metabolite M-II. Efficacy may be reduced when ramelteon is used in combination with strong CYP enzyme inducers such as rifampin [see Clinical Pharmacology (12.5) ] . Ketoconazole (strong CYP3A4 inhibitor) The AUC 0-inf and C max of ramelteon increased by approximately 84% and 36% upon coadministration of ketoconazole with ramelteon. Ramelteon should be administered with caution in subjects taking strong CYP3A4 inhibitors such as ketoconazole [see Clinical Pharmacology (12.5) ] . Fluconazole (strong CYP2C9 inhibitor) The AUC 0-inf and C max of ramelteon was increased by approximately 150% when ramelteon was coadministered with fluconazole. Ramelteon should be administered with caution in subjects taking strong CYP2C9 inhibitors such as fluconazole [see Clinical Pharmacology (12.5) ] . Donepezil The AUC 0-inf and C max of ramelteon increased by approximately 100% and 87%, respectively upon coadministration of donepezil with ramelteon. Patients should be closely monitored when ramelteon is coadministered with donepezil [see Clinical Pharmacology (12.5) ] . Doxepin The AUC 0-inf and C max of ramelteon increased by approximately 66% and 69%, respectively, upon coadministration of doxepin with ramelteon. Patients should be closely monitored when ramelteon is coadministered with doxepin [see Clinical Pharmacology (12.5) ] . 7.2 Effect of Alcohol on Ramelteon Alcohol by itself impairs performance and can cause sleepiness. Since the intended effect of ramelteon is to promote sleep, patients should be cautioned not to consume alcohol when using ramelteon [see Clinical Pharmacology (12.5) ] . Use of the products in combination may have an additive effect. 7.3 Drug/Laboratory Test Interactions Ramelteon is not known to interfere with commonly used clinical laboratory tests. In addition, in vitro data indicate that ramelteon does not cause false-positive results for benzodiazepines, opiates, barbiturates, cocaine, cannabinoids, or amphetamines in two standard urine drug screening methods in vitro .