Zolmitriptan is a triptan used to treat migraine attacks with or without aura and cluster headaches. It is a selective serotonin receptor agonist of the 1B and 1D subtypes.
It was patented in 1990 and approved for medical use in 1997.
Structure:
Physicochemical Data:
IUPAC Name | (S)-4-({3-[2-(Dimethylamino)ethyl]-1H-indol-5-yl}methyl)-1,3-oxazolidin-2-one |
CAS Number | 139264-17-8 |
Molecular Formula | C16H21N3O2 |
Molecular Mass | 287.363 g·mol−1 |
Melting Point | |
Density |
Pharmacokinetic Data:
Absorption | Zolmitriptan tablets have a mean absolute oral bioavailability of approximately 40%, with food not affecting the rate or extent of absorption. The dosing kinetics are linear over a range of 2.5 to 50 mg with 75% of the eventual Cmax being attained within 1 hour of dosing. The median Tmax for the tablet form is 1.5 hours, while for the orally disintegrating tablet form, it is 3 hours. The AUC across studies was in the range of 84.4-173.8 ng/mL*h while the Cmax was between 16 and 25.2 ng/mL. Zolmitriptan administered as a nasal spray is detected in the plasma within 2-5 minutes, compared to 10-15 minutes for the tablet form; the faster kinetics likely reflect fast absorption across the nasal mucosa. The bioavailability compared to the tablet is 102%, and plasma zolmitriptan concentration is maintained for 4-6 hours after intranasal delivery. The active N-desmethyl metabolite of zolmitriptan has a mean plasma concentration that is roughly two-thirds of zolmitriptan, regardless of dosage route or concentration. |
Volume of Distribution | Zolmitriptan has a volume of distribution between 7 and 8.4 L/kg. |
Protein Binding | Zolmitriptan and its active N-desmethyl metabolite remain approximately 25% bound to plasma proteins over a concentration range of 10-1000 ng/mL. |
Metabolism | Zolmitriptan is metabolized in the liver, and studies using cytochrome P450 inhibitors like cimetidine suggest that it is likely metabolized by CYP1A2, as well as by monoamine oxidase (MAO). Zolmitriptan metabolism results in three major metabolites: an active N-desmethyl metabolite (183C91) as well as inactive N-oxide (1652W92) and indole acetic acid (2161W92) metabolites. |
Route of Elimination | Zolmitriptan is primarily excreted in urine (approximately 65%) and feces (approximately 30%). Within urine, the most common form is the indole acetic acid metabolite (31%), followed by the N-oxide (7%), and N-desmethyl (4%) metabolites; the majority of zolmitriptan recovered in feces remains unchanged. |
Half-life | Zolmitriptan has a mean elimination half-life of approximately three hours following oral or nasal administration. Its active N-desmethyl metabolite has a slightly longer (approximately 3.5 hours) half-life. |
Clearance | Zolmitriptan has a clearance of 31.5 mL/min/kg for oral tablets and 25.9 mL/min/kg for nasal administration; one-sixth of the clearance is renal. |
Toxicity | Toxicity information regarding zolmitriptan is not readily available. Patients experiencing an overdose are at an increased risk of severe adverse effects such as cardiovascular symptoms due to excessive vasoconstriction and activation of serotonergic receptors. Patients receiving a single 50 mg oral dose of zolmitriptan often experienced sedation. Symptomatic and supportive measures are recommended. |
References: