Overview
11 DESCRIPTION Naratriptan tablets, USP contains naratriptan hydrochloride, a selective 5-HT 1B/1D receptor agonist. Naratriptan hydrochloride is chemically designated as N-methyl-3-(1-methyl-4-piperidinyl)-1H-indole-5-ethanesulfonamide monohydrochloride, and it has the following structure: The empirical formula is C 17 H 25 N 3 O 2 S•HCl, representing a molecular weight of 371.93.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 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. 12.
Indications
- 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.
Common Doses
- 1 mg
- 2.5 mg
- 5 mg
- 15 mL
Dosage
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.
Contraindications
- 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.
Side Effects
- 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.
Interactions
- 7 DRUG INTERACTIONS 7.1 Ergot-Containing Drugs Ergot-containing drugs have been reported to cause prolonged vasospastic reactions. Because these effects may be additive, use of ergotamine-containing or ergot-type medications (like dihydroergotamine or methysergide) and naratriptan within 24 hours of each other is contraindicated. 7.2 Other 5-HT 1 Agonists Concomitant use of other 5-HT 1B/1D agonists (including triptans) within 24 hours of treatment with naratriptan is contraindicated because the risk of vasospastic reactions may be additive. 7.