Sumatriptan

Chemical Properties

White crystalline powder, easily soluble in water. Melting point 169-171°C.
Sumatriptan succinate: C14H21N3O2SC4H5O4. [103628-48-4]. Melting point 165-166°C.

Originator

Imigran,GlaxoSmithKline,UK

Uses

Serotonin 5HT1 receptor agonist; treatment of migraine.

Uses

Sumatriptan is a serotonin 5HT1-receptor agonist.

Definition

ChEBI: A sulfonamide that consists of N,N-dimethyltryptamine bearing an additional (N-methylsulfamoyl)methyl substituent at position 5. Selective agonist for a vascular 5-HT1 receptor s btype (probably a member of the 5-HT1D family). Used (in the form of its succinate salt) for the acute treatment of migraine with or without aura in adults.

Manufacturing Process

A solution of (phenylthio)acetaldehyde (6.05 g) in absolute ethanol (180 ml) was added over 10 min to a solution of 4-hydrazino-Nmethylbenzenemethanesulphonamide hydrochloride (10 g) in water (180 ml) with cooling. After addition of the aldehyde was complete, the mixture was stirred at 5°C for a period of 14 h. The precipitated solid was filtered off, washed with water (200 ml), hexane (200 ml) and dried in vacuo to give the N-methyl-4-[2-[2-(phenylthio)ethylidene]hydrazino]benzenemethanesulphonamide (10.95 g), melting point 110°-112°C.
A solution of the N-methyl-4-[2-[2- (phenylthio)ethylidene]hydrazino]benzenemethane-sulphonamide in absolute ethanol (300 ml) was saturated with hydrogen chloride gas (ca. 30 min) whilst being cooled in an ice-water bath, allowed to stir at room temperature for 3 h and filtered. The filtrate was concentrated in vacuo and chromatographed to afford a foam, which solidified on trituration with ether to an amorphous powder (2.17 g). A sample was recrystallized from hexane-dichloromethane to give the N-methyl-3-(phenylthio)-1H-indole-5-methanesulphonamide, melting point 133°-134°C.
To a solution of N-methyl-3-(phenylthio)-1H-indole-5-methanesulphonamide (460 mg) in absolute ethanol (50 ml) was added Raney nickel [4.6 g, 50% slurry in water, washed to neutrality with deionized water (60 ml)] and the reaction mixture refluxed for 16 h under an atmosphere of nitrogen. On cooling to room temperature, the supernatant was removed and the Raney nickel extracted with ethanol (2x50 ml, which was brought to a gentle reflux for 15 min under an atmosphere of nitrogen). The combined extracts were filtered through a sand-celite pad and concentrated in vacuo. Chromatography of the residue, afforded an oil (87 mg) which crystallized from ether-hexane to give the N-methyl-1H-indole-5-methanesulphonamide (90 mg), melting point 127°-129°C.
To N,N-diethyl chloroacetamide (800 mg) at 0°C was added phosphorous oxychloride (250 μl) over a period of 30 sec. After the addition was complete, the mixture was allowed to stir at 0°C for 15 min and then at room temperature for 20 min. The N-methyl-1H-indole-5-methanesulphonamide (300 mg) was added at 0°C and the mixture warmed to 65°C, whereupon it dissolved. The mixture was stirred for 2 h at this temperature then poured onto ice (ca. 5 g) and chloroform (5 ml) and stirred vigorously for 1 h. A solid was filtered off, washed with water (50 ml), and hexane (100 ml) and dried in vacuo to give the 3-(chloroacetyl)-N-methyl-1H-indole-5- methanesulphonamide (192 mg).
A solution of the 3-(chloroacetyl)-N-methyl-1H-indole-5- methanesulphonamide (160 mg) in ethanolic dimethylamine (30 ml, 33% w/v solution in ethanol) was heated to reflux for 2 h. On cooling to room temperature the solvent was removed in vacuo and the residue was chromatographed to afford the 3-[(dimethylamino)acetyl]-N-methyl-1Hindole- 5-methanesulphonamide, melting point 230°C, dec.
To a suspension of the 3-[(dimethylamino)acetyl]-N-methyl-1H-indole-5- methanesulphonamide (46.5 mg) in 1-propanol (5 ml) was added sodium borohydride (62 mg). The reaction mixture was brought to reflux for a period of 3 h, then an additional quantity of borohydride (60 mg) was added. After refluxing for a further 1 h, the mixture was allowed to cool to room temperature and quenched with 2 N HCl (10 ml). The aqueous solution was washed with ethyl acetate (5 ml) then neutralized (NaHCO3 solution) and extracted with ethyl acetate (3 x 15 ml). The combined extracts were concentrated in vacuo and the residue chromatographed to give the 3-[2- (dimethylamino)ethyl]-N-methyl 1H-indole-5-methanesulphonamide as a gum (2 mg) which was shown by TLC.
Succinic acid in hot methanol was added to a hot solution of the the 3-[2- (dimethylamino)ethyl]-N-methyl-1H-indole-5-methanesulphonamide in absolute ethanol and the mixture was heated to reflux with stirring to give a solution. The solution was allowed to cool with stirring to room temperature, and the resultant suspension was farther cooled in an ice-bath for 2 h. The solid was filtered off, washed with ethanol, and dried in vacuo to give the 3- [2-(dimethylamino)ethyl]-N-methyl-1H-indole-5-methanesulphonamide, salt with succinic acid (1:1).

brand name

Imitrex (GlaxoSmithKline).

Therapeutic Function

Serotoninergic

General Description

Sumatriptan was the first triptan approved (1991) for theacute treatment of migraine headaches. It has the lowestoral bioavailability among all triptans because of its lowlipophilicity. The availability of many different dosageforms (i.e., an oral tablet, a SC injection, a nasal spray formulation,and a suppository) allows the flexibility of tailoringtherapy to the needs of the individual patients, thusmaking sumatriptans a very useful drug for an acute treatmentof migraine headaches. It also has a very fastonset of action via SC injection or nasal spray administration.However, sumatriptan is contraindicated withmonoamine oxidase inhibitors because it is primarily degradedby hepatic MAO-A. Thus, it may require frequentdosing as a result of its short duration of action to preventmigraine recurrence.

Clinical Use

5HT1 receptor agonist:
Acute relief of migraine

Drug interactions

Potentially hazardous interactions with other drugs
Antidepressants: increased risk of CNS toxicity with citalopram, escitalopram, fluoxetine and fluvoxamine - avoid with citalopram; risk of CNS toxicity with MAOIs, moclobemide, SSRIs, sertraline, St John’s Wort - avoid; possibly increased serotonergic effects with duloxetine and venlafaxine.
Dapoxetine: possible increased risk of serotonergic effects - avoid for 2 weeks after stopping 5HT1 agonists.
Ergot alkaloids: increased risk of vasospasm - avoid.

Metabolism

Sumatriptan is extensively metabolised in the liver mainly by monoamine oxidase type A and is excreted mainly in the urine as the inactive indole acetic acid derivative and its glucuronide.
Non-renal clearance accounts for about 80% of the total clearance. The remaining 20% is excreted in urine, mainly as metabolites, by active renal tubular secretion. Sumatriptan and its metabolites also appear in the faeces.