Naratriptan

1 INDICATIONS AND USAGE Naratriptan tablets are indicated for the acute treatment of migraine with or without aura in adults. Limitations of Use: Use only if a clear diagnosis of migraine has been established. If a patient has no response to the first migraine attack treated with naratriptan tablets reconsider the diagnosis of migraine before naratriptan tablets are administered to treat any subsequent attacks. Naratriptan tablets are not indicated for the prevention of migraine attacks. Safety and effectiveness of naratriptan tablets have not been established for cluster headache. Naratriptan Tablets are serotonin (5-HT 1B/1D ) receptor agonists (triptan) indicated for the acute treatment of migraine with or without aura in adults. (1) Limitations of Use: Use only if a clear diagnosis of migraine has been established. (1) Not indicated for the prophylactic therapy of migraine attacks. (1) Not indicated for the treatment of cluster headache. (1)

12.1 Mechanism of Action Naratriptan binds with high affinity to human cloned 5-HT 1B/1D receptors. Migraines are likely due to local cranial vasodilatation and/or to the release of sensory neuropeptides (including substance P and calcitonin gene-related peptide) through nerve endings in the trigeminal system. The therapeutic activity of naratriptan for the treatment of migraine headache is thought to be due to the agonist effects at the 5-HT 1B/1D receptors on intracranial blood vessels (including the arterio-venous anastomoses) and sensory nerves of the trigeminal system, which result in cranial vessel constriction and inhibition of pro-inflammatory neuropeptide release.

2 DOSAGE AND ADMINISTRATION Recommended dose: 1 mg or 2.5 mg. ( 2.1 ) May repeat dose after 4 hours if needed; not to exceed 5 mg in any 24- hour period. ( 2.1 ) Mild or moderate renal or hepatic impairment: recommended starting dose is 1 mg not to exceed 2.5 mg in any 24-hour period. ( 2.2 , 2.3 ) 2.1 Dosing Information The recommended dose of naratriptan tablets is 1 mg or 2.5 mg. If the migraine returns or if the patient has only partial response, the dose may be repeated once after 4 hours, for a maximum dose of 5 mg in a 24-hour period. The safety of treating an average of more than 4 migraine attacks in a 30-day period has not been established. 2.2 Dosage Adjustment in Patients With Renal Impairment Naratriptan tablets are contraindicated in patients with severe renal impairment (creatinine clearance: <15 mL/min) because of decreased clearance of the drug [see Contraindications (4) , Use in Specific Populations (8.6) , Clinical Pharmacology (12.3) ]. In patients with mild to moderate renal impairment, the maximum daily dose should not exceed 2.5 mg over a 24-hour period and a 1-mg starting dose is recommended [see Use in Specific Populations (8.6) , Clinical Pharmacology (12.3) ]. 2.3 Dosage Adjustment in Patients With Hepatic Impairment Naratriptan tablets are contraindicated in patients with severe hepatic impairment (Child-Pugh Grade C) because of decreased clearance [see Contraindications (4) , Use in Specific Populations (8.7) , Clinical Pharmacology (12.3) ]. In patients with mild or moderate hepatic impairment (Child-Pugh Grade A or B), the maximum daily dose should not exceed 2.5 mg over a 24-hour period and a 1-mg starting dose is recommended [ see Use in Specific Populations (8.7) , Clinical Pharmacology (12.3) ].

6 ADVERSE REACTIONS The following adverse reactions are discussed in more detail in other sections of the prescribing information: Myocardial ischemia, myocardial infarction, and Prinzmetal's angina [see Warnings and Precautions (5.1 ) ] Arrhythmias [see Warnings and Precautions (5.2) ] Chest, throat, neck, and/or jaw pain/tightness/pressure [see Warnings and Precautions (5.3) ] Cerebrovascular events [see Warnings and Precautions (5.4) ] Other vasospasm reactions [s ee Warnings and Precautions (5.5) ] Medication overuse headache [see Warnings and Precautions (5.6) ] Serotonin syndrome [see Warnings and Precautions (5.7) ] Increase in blood pressure [see Warnings and Precautions (5.8) ] Hypersensitivity reactions [see Contraindications (4) , Warnings and Precautions (5.9) ] Most common adverse reactions (≥2% and >placebo) were paresthesias, nausea, dizziness, drowsiness, malaise/fatigue, and throat/neck symptoms. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Avet Pharmaceuticals Inc. at 1-866-901-DRUG (3784) 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 with rates in the clinical trials of another drug and may not reflect the rates observed in practice. In a long-term open-label trial where patients were allowed to treat multiple migraine attacks for up to 1 year, 15 patients (3.6%) discontinued treatment due to adverse reactions. In controlled clinical trials, the most common adverse reactions were paresthesias, dizziness, drowsiness, malaise/fatigue, and throat/neck symptoms, which occurred at a rate of 2% and at least 2 times placebo rate. Table 1 lists the adverse reactions that occurred in 5 placebo-controlled clinical trials of approximately 1,752 exposures to placebo and naratriptan tablets in adult patients with migraine. Only reactions that occurred at a frequency of 2% or more in groups treated with naratriptan tablets 2.5 mg and that occurred at a frequency greater than the placebo group in the 5 pooled trials are included in Table 1. Table 1. Adverse Reactions Reported by at Least 2% of Patients Treated With Naratriptan Tablets and at a Frequency Greater Than Placebo Adverse Reaction Percent of Patients Reporting Naratriptan Tablets 1 mg (n = 627) Naratriptan Tablets 2.5 mg (n = 627) Placebo (n = 498) Atypical sensation 2 4 1 Paresthesias (all types) 1 2 <1 Gastrointestinal 6 7 5 Nausea 4 5 4 Neurological 4 7 3 Dizziness 1 2 1 Drowsiness 1 2 <1 Malaise/fatigue 2 2 1 Pain and pressure sensation 2 4 2 Throat/neck symptoms 1 2 1 The incidence of adverse reactions in controlled clinical trials was not affected by age or weight of the patients, duration of headache prior to treatment, presence of aura, use of prophylactic medications, or tobacco use. There were insufficient data to assess the impact of race on the incidence of adverse reactions.

5 WARNINGS AND PRECAUTIONS Myocardial ischemia/infarction and Prinzmetal's angina: Perform cardiac evaluation in patients with multiple cardiovascular risk factors. ( 5.1 ) Arrhythmias: Discontinue naratriptan if occurs . ( 5.2 ) Chest/throat/neck/jaw pain, tightness, pressure, or heaviness: Generally not associated with myocardial ischemia; evaluate for CAD in patients at high risk. ( 5.3 ) Cerebral hemorrhage, subarachnoid hemorrhage, and stroke: Discontinue naratriptan if occurs . ( 5.4 ) Gastrointestinal ischemic reactions and peripheral vasospastic reactions: Discontinue naratriptan if occurs. ( 5.5 ) Medication overuse headache: Detoxification may be necessary. ( 5.6 ) Serotonin syndrome: Discontinue naratriptan if occurs. ( 5.7 ) 5.1 Myocardial Ischemia, Myocardial Infarction, and Prinzmetal's Angina Naratriptan is contraindicated in patients with ischemic or vasospastic CAD. There have been rare reports of serious cardiac adverse reactions, including acute myocardial infarction, occurring within a few hours following administration of naratriptan. Some of these reactions occurred in patients without known CAD. Naratriptan may cause coronary artery vasospasm (Prinzmetal's angina), even in patients without a history of CAD. Perform a cardiovascular evaluation in triptan-naive patients who have multiple cardiovascular risk factors (e.g., increased age, diabetes, hypertension, smoking, obesity, strong family history of CAD) prior to receiving naratriptan. If there is evidence of CAD or coronary artery vasospasm, naratriptan is contraindicated. For patients with multiple cardiovascular risk factors who have a negative cardiovascular evaluation, consider administering the first dose of naratriptan in a medically supervised setting and performing an electrocardiogram (ECG) immediately following administration of naratriptan. For such patients, consider periodic cardiovascular evaluation in intermittent long-term users of naratriptan. 5.2 Arrhythmias Life-threatening disturbances of cardiac rhythm, including ventricular tachycardia and ventricular fibrillation leading to death, have been reported within a few hours following the administration of 5-HT 1 agonists. Discontinue naratriptan if these disturbances occur. Naratriptan is contraindicated in patients with Wolff-Parkinson-White syndrome or arrhythmias associated with other cardiac accessory conduction pathway disorders. 5.3 Chest, Throat, Neck, and/or Jaw Pain/Tightness/Pressure Sensations of tightness, pain, and pressure in the chest, throat, neck, and jaw commonly occur after treatment with naratriptan and are usually non-cardiac in origin. However, perform a cardiac evaluation if these patients are at high cardiac risk. 5-HT 1 agonists, including naratriptan, are contraindicated in patients with CAD and those with Prinzmetal's variant angina. 5.4 Cerebrovascular Events Cerebral hemorrhage, subarachnoid hemorrhage, and stroke have occurred in patients treated with 5-HT 1 agonists, and some have resulted in fatalities. In a number of cases, it appears possible that the cerebrovascular events were primary, the 5-HT 1 agonist having been administered in the incorrect belief that the symptoms experienced were a consequence of migraine when they were not. Also, patients with migraine may be at increased risk of certain cerebrovascular events (e.g., stroke, hemorrhage, TIA). Discontinue naratriptan if a cerebrovascular event occurs. Before treating headaches in patients not previously diagnosed as migraineurs, and in migraineurs who present with symptoms atypical for migraine, exclude other potentially serious neurological conditions. Naratriptan is contraindicated in patients with a history of stroke or TIA. 5.5 Other Vasospasm Reactions Naratriptan may cause non-coronary vasospastic reactions, such as peripheral vascular ischemia, gastrointestinal vascular ischemia and infarction (presenting with abdominal pain and bloody diarrhea), splenic infarction, and Raynaud's syndro

4 CONTRAINDICATIONS Naratriptan tablets are contraindicated in patients with: Ischemic coronary artery disease (CAD) (angina pectoris, history of myocardial infarction, or documented silent ischemia) or coronary artery vasospasm, including Prinzmetal's angina [see Warnings and Precautions (5.1) ] Wolff-Parkinson-White syndrome or arrhythmias associated with other cardiac accessory conduction pathway disorders [see Warnings and Precautions (5.2) ] History of stroke or transient ischemic attack (TIA) or history of hemiplegic or basilar migraine because such patients are at a higher risk of stroke [see Warnings and Precautions (5.4) ] Peripheral vascular disease [see Warnings and Precautions (5.5) ] Ischemic bowel disease [see Warnings and Precautions (5.5) ] Uncontrolled hypertension [see Warnings and Precautions (5.8) ] Recent use (i.e., within 24 hours) of another 5-HT 1 agonist, ergotamine-containing medication, ergot-type medication (such as dihydroergotamine or methysergide) [see Drug Interactions ( 7.1 , 7.2 )] Hypersensitivity to naratriptan (angioedema and anaphylaxis seen) [see Warnings and Precautions (5.9) ] Severe renal or hepatic impairment [see Use in Specific Populations ( 8.6 , 8.7 ), Clinical Pharmacology (12.3) ] History of coronary artery disease or coronary artery vasospasm ( 4 ) Wolff-Parkinson-White syndrome or other cardiac accessory conduction pathway disorders ( 4 ) History of stroke, transient ischemic attack, or hemiplegic or basilar migraine ( 4 ) Peripheral vascular disease ( 4 ) Ischemic bowel disease ( 4 ) Uncontrolled hypertension ( 4 ) Recent (within 24 hours) use of another 5-HT 1 agonist (e.g., another triptan) or an ergotamine-containing medication ( 4 ) Hypersensitivity to naratriptan (angioedema and anaphylaxis seen) ( 4 ) Severe renal or hepatic impairment ( 4 )

10 OVERDOSAGE Adverse reactions observed after overdoses of up to 25 mg included increases in blood pressure resulting in lightheadedness, neck tension, tiredness, and loss of coordination. Also, ischemic ECG changes likely due to coronary artery vasospasm have been reported. The elimination half-life of naratriptan is about 6 hours [see C linical Pharmacology (12.3) ], and therefore monitoring of patients after overdose with naratriptan should continue for at least 24 hours or while symptoms or signs persist. There is no specific antidote to naratriptan. It is unknown what effect hemodialysis or peritoneal dialysis has on the serum concentrations of naratriptan.