Naratriptan

Naratriptan

Systematic (IUPAC) name
N-methyl-2-[3-(1-methylpiperidin-4-yl)-1H-indol-5-yl]ethanesulfonamide
Clinical data
Trade names	Amerge
AHFS/Drugs.com	monograph
MedlinePlus	a601083
Pregnancy category	AU: B3 US: C (Risk not ruled out)
Legal status	℞ (Prescription only)
Routes of administration	Oral
Pharmacokinetic data
Bioavailability	74%
Metabolism	Hepatic
Biological half-life	5-8 hours
Excretion	Renal
Identifiers
CAS Number	121679-13-8 Y
ATC code	N02CC02 (WHO)
PubChem	CID: 4440
IUPHAR/BPS	45
DrugBank	DB00952 Y
ChemSpider	4287 Y
UNII	QX3KXL1ZA2 Y
KEGG	D08255 Y
ChEBI	CHEBI:7478 Y
ChEMBL	CHEMBL1278 Y
Chemical data
Formula	C17H25N3O2S
Molecular mass	335.465 g/mol
SMILES O=S(=O)(NC)CCc3ccc1c(c(cn1)C2CCN(C)CC2)c3
InChI InChI=1S/C17H25N3O2S/c1-18-23(21,22)10-7-13-3-4-17-15(11-13)16(12-19-17)14-5-8-20(2)9-6-14/h3-4,11-12,14,18-19H,5-10H2,1-2H3 Y Key:AMKVXSZCKVJAGH-UHFFFAOYSA-N Y
(verify)

Naratriptan (trade names include Amerge and Naramig) is a triptan drug marketed by GlaxoSmithKline and is used for the treatment of migraine headaches. Naratriptan is available in 2.5 mg tablets. It is a selective 5-HT₁ receptor subtype agonist.

Indication

Naratriptan is used for the treatment of the acute migraine attacks and the symptoms of migraine, including severe, throbbing headaches that sometimes are accompanied by nausea and sensitivity to sound or light.

Mechanism of action

The causes of migraine are not clearly understood; however, the efficacy of naratriptans and other triptans is believed to be due to their activity as 5HT (serotonin) agonists.

Efficacy

A meta-analysis of 53 clinical trials has shown that all triptans are effective for treating migraine at marketed doses and that naratriptan, although less effective than sumatriptan and rizatriptan was more effective than placebo in reducing migraine symptoms at two hours and efficacy was demonstrated in almost two thirds of subjects after four hours of treatment.

Side effects

Side effects include: dizziness, drowsiness, tingling of the hands or feet, nausea, dry mouth and unsteadiness. If these effects persist or worsen, notify your doctor promptly. Side-effects which are unlikely and which should be promptly reported include: chest pain/pressure, throat pain/pressure, unusually fast/slow/irregular pulse, one-sided muscle weakness, vision problems, cold/bluish hands or feet, stomach pain, bloody diarrhea, mental/mood changes, and fainting. In the unlikely event you have a serious allergic reaction to this drug, seek immediate medical attention. Symptoms of a serious allergic reaction include: rash, itching, swelling, severe dizziness, trouble breathing (swelling of the throat).

The use of naratriptan with MAOIs and serotonergic drugs may result in the life threatening serotonin syndrome. Make sure your doctor/pharmacist is aware of all your current medications (including as needed medications) before taking this drug.

Exclusivity

In the United States, the Food and Drug Administration (FDA) approved naratriptan on February 11, 1998. It was covered by U.S. Patent no. 4997841; the FDA lists the patent as expiring on July 7, 2010.

In July 2010, in the wake of the patent expiration, several drug manufacturers, including Roxane Labs, Sandoz and Teva Pharmaceuticals, announced that they were launching generic Naratriptan medications.

The drug continued to be covered by European patent 0303507 in Germany, Spain, France and the United Kingdom through March 10, 2012, and by Australian patent 611469 in Australia through June 17, 2013. It had previously been covered by Canadian patent 1210968; but both Sandoz and Teva (formerly Novopharm) have offered generic equivalents in Canada since that patent's expiration December 1, 2009.

Since December 23rd, 2014 in Canada both generic versions of naratriptan have been unavailable to consumers because of a quarantine on the only two sites producing the necessary ingredient used by Sandoz and Teva for distribution in Canada: IPCA Laboratories in Pithampur, India and Dr. Reddy's Laboratories in Srikakulam, India.