ZOLMITRIPTAN
Clinical safety rating: avoid
Contraindicated (not allowed)
Selective serotonin 5-HT1B/1D receptor agonist; causes vasoconstriction of intracranial blood vessels and inhibits trigeminal nerve transmission.
| Metabolism | Hepatic via CYP1A2, with metabolites N-desmethylzolmitriptan (active) and N-oxide and indoleacetic acid derivatives. |
| Excretion | Zolmitriptan is eliminated primarily via hepatic metabolism, with approximately 60% excreted in urine (8-10% as unchanged drug, the remainder as indoleacetic acid and N-oxide metabolites) and 30% in feces. Biliary excretion is negligible. |
| Half-life | Terminal elimination half-life is approximately 3 hours (range 2.5-4.5 hours) for oral and intranasal routes. This short half-life is consistent with the need for acute migraine treatment and supports the possibility of recurrence within 24 hours. |
| Protein binding | Approximately 25% bound to plasma proteins (mainly albumin), which is low and not clinically significant. |
| Volume of Distribution | Volume of distribution is approximately 2.4 L/kg (range 1.8-3.0 L/kg), indicating extensive tissue distribution including penetration across the blood-brain barrier. |
| Bioavailability | Oral bioavailability is 40-48% (first-pass metabolism); intranasal: approximately 40% (similar to oral); orally disintegrating tablet: equivalent to oral tablet. |
| Onset of Action | Oral: onset of effect occurs within 30-60 minutes; intranasal: within 15-30 minutes; orally disintegrating tablet: similar to oral. |
| Duration of Action | Duration of action is 2-4 hours for headache relief, but migraine recurrence within 24 hours is common (up to 30-40%) due to the short half-life. |
| Molecular Weight | 287.36 |
2.5 mg or 5 mg orally at onset of migraine; may repeat after 2 hours if needed, maximum 10 mg in 24 hours. Also available as 5 mg nasal spray or 3 mg subcutaneous injection (single dose).
| Dosage form | TABLET |
| Renal impairment | No specific dose adjustment required for mild to moderate renal impairment (CrCl >15 mL/min). For severe renal impairment (CrCl ≤15 mL/min), use is contraindicated due to lack of data. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh C). For moderate impairment (Child-Pugh B), maximum dose 5 mg in 24 hours. No adjustment needed for mild impairment (Child-Pugh A). |
| Pediatric use | Adolescents ≥12 years: 2.5 mg or 5 mg orally at onset, may repeat after 2 hours, maximum 10 mg in 24 hours. Nasal spray: 5 mg single dose. Safety and efficacy not established in children <12 years. |
| Geriatric use | Not recommended in elderly patients due to increased risk of coronary artery disease and decreased hepatic function; use only if clearly indicated with careful monitoring. |
| 1st trimester | Limited human data; animal studies show embryonic/fetal toxicity at maternally toxic doses. Avoid unless benefit outweighs risk. |
| 2nd trimester | Limited human data; use only if clearly needed and potential benefit justifies potential risk to fetus. |
| 3rd trimester | May cause uterine contractions or preterm labor; avoid use near term due to potential for neonatal adverse effects. |
Clinical note
Other 5-HT1 agonists and MAOIs can have additive effects Contraindicated in ischemic heart disease and uncontrolled hypertension.
| Placental transfer | Zolmitriptan crosses the placenta in humans; fetal plasma concentrations are approximately 20-30% of maternal concentrations based on limited data. |
| Breastfeeding | Zolmitriptan enters breast milk in low amounts (relative infant dose estimated <4% of maternal weight-adjusted dose). However, due to potential for adverse effects in infants, caution is advised, especially in neonates or preterm infants. Monitor infant for signs of triptan-related effects (e.g., drowsiness, irritability). |
■ FDA Black Box Warning
Do not use within 24 hours of any triptan or ergotamine-containing medication due to risk of additive vasospastic reactions.
| Common Effects | Dizziness |
| Serious Effects |
History of ischemic heart disease or coronary artery vasospasm (e.g., Prinzmetal's angina)History of cerebrovascular disease (e.g., stroke, transient ischemic attack)Peripheral vascular disease (e.g., ischemic bowel disease)Uncontrolled hypertensionWithin 24 hours of another triptan or ergotamine-containing medicationSevere hepatic impairment (Child-Pugh class C)Concomitant or recent use (within 2 weeks) of monoamine oxidase inhibitor (MAOI)
| Precautions | Risk of myocardial ischemia, arrhythmias, and cerebrovascular events; avoid in patients with uncontrolled hypertension; serotonin syndrome possible with SSRIs/SNRIs. |
| Food/Dietary |
Loading safety data…
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | Limited human data; animal studies show no evidence of teratogenicity. In first trimester, risk cannot be ruled out. Second and third trimesters: No known fetal risks; however, uterine vasoconstriction may theoretically reduce placental perfusion. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate during administration. In late pregnancy, monitor fetal heart rate and uterine activity due to potential vasoconstrictive effects. |
| Fertility Effects | No known adverse effects on fertility in humans. Animal studies at high doses showed reduced fertility; clinical significance unknown. |
| No significant food interactions. Grapefruit juice may slightly increase zolmitriptan levels but clinical significance is minimal. No specific dietary restrictions. However, avoid alcohol as it can worsen migraine symptoms or side effects. |
| Clinical Pearls | Zolmitriptan is a 5-HT1B/1D receptor agonist used for acute migraine treatment. Onset of action within 30 minutes; nasal spray and ODT formulations offer faster absorption. Contraindicated in patients with ischemic heart disease, Prinzmetal's angina, uncontrolled hypertension, or within 24 hours of other triptans or ergotamines. Not for prophylaxis. Avoid use within 2 weeks of MAO inhibitors. Overuse (≥10 days/month) can lead to medication-overuse headache. Monitor for serotonin syndrome if combined with SSRIs/SNRIs. |
| Patient Advice | Take zolmitriptan at the first sign of a migraine headache for best results. · Do not take more than 10 mg in any 24-hour period. · If the headache returns after initial relief, a second dose may be taken after at least 2 hours. · Contact your doctor immediately if you experience chest pain, shortness of breath, or irregular heartbeat. · Avoid taking other triptans or ergotamine-containing medications within 24 hours of zolmitriptan. · Do not use zolmitriptan if you have uncontrolled high blood pressure, heart disease, or a history of stroke. · If you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor before use. · Store at room temperature away from moisture and heat. · Report any tingling, numbness, or unusual sensations to your healthcare provider. · Do not drive or operate machinery until you know how zolmitriptan affects you, as it may cause dizziness or drowsiness. |