Zolmitriptan
Zolmitriptan. Selective 5-HT1B/1D receptor agonist (triptan) for acute migraine — cranial vasoconstriction and trigeminal inhibition; also binds… Oral half-life 2.3 h.
Selective 5-HT1B/1D receptor agonist (triptan) for acute migraine — cranial vasoconstriction and trigeminal inhibition; also binds 5-HT1F. Active N-desmethyl metabolite.
PK from FDA prescribing information (DailyMed setid 333caafc-2e63-49f8-a0c6-534e528d228d): mean absolute bioavailability ~40% (F 0.4), apparent Vd 7 L/kg (~490 L), elimination t½ ~3 h, Tmax ~1.5 h (tablet). ka_hr 1.5 derived from Tmax 1.5 h (ke from t½ 3 h). PK: THE RECORD SELF-DOCUMENTED ITS OWN COLLISION. Its source_label read "Tmax ~1.5 h (tablet)" while ka_hr was 1.5, and the same label said "apparent Vd" while the row paired it with an independent bioavailability — a double-division disclosed in the record own text. V 490 L is also byte-identical to DIGOXIN stored volume, and is about four times the only intravenous determination: the primary gives "8.7 +/- 1.7 ml min-1 kg-1, 122 ... and 2.30 +/- 0.59 h" after intravenous dosing, and an independent population fit agrees at 136 L. F corrected 0.4 to the stated 0.49. THE EFFECT-COMPARTMENT VALUE IS REMOVED AND BOTH ITS REFERENCES ARE THE WRONG DRUG — one is an eletriptan binding study in cultured cells, the other never mentions zolmitriptan at all. That second paper contains "the time to reach equilibrium was approximately 2 h", a rat-brain-homogenate binding equilibration, which is a plausible origin for the stored 2 /h and is exactly the shape of a pharmacodynamic quantity read as a kinetic one. ANALYTE: all values describe the parent, while the active N-desmethyl metabolite is more potent and its exposure differs by route and age.
Pharmacokinetics
- Oral — t½ 2.3 h · F 49% · Vd 122 L
Sources: PMID:9205817, PMID:10357516, PMID:18028032