MAXALT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MAXALT (MAXALT).
Selective serotonin 5-HT1B/1D receptor agonist; causes vasoconstriction of cranial arteries and inhibits trigeminal nerve signaling.
| Metabolism | Primarily metabolized by monoamine oxidase A (MAO-A); minor metabolism by CYP1A2, CYP2D6, and CYP3A4. The major metabolite is the inactive indole acetic acid analog. |
| Excretion | Renal (60% as unchanged drug and metabolites) and fecal (40% primarily as metabolites). |
| Half-life | 2-3 hours in plasma; clinical effect correlates with distribution to CNS rather than plasma half-life. |
| Protein binding | 14% bound primarily to albumin. |
| Volume of Distribution | 3.1 L/kg, indicating extensive tissue distribution including CNS penetration. |
| Bioavailability | Oral: 45% (first-pass metabolism); orally disintegrating tablet: equivalent. |
| Onset of Action | Oral: 30-60 minutes; orally disintegrating tablet: similar. |
| Duration of Action | Clinical effect 2-4 hours; headache recurrence possible within 24 hours. |
5 mg or 10 mg orally at onset of migraine; maximum 30 mg in 24 hours (two doses with at least 2 hours between them).
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (CrCl ≥30 mL/min). For severe renal impairment (CrCl <30 mL/min), maximum dose is 5 mg per 24 hours. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh C). For mild to moderate impairment (Child-Pugh A or B), maximum dose is 5 mg per dose; do not exceed 2 doses in 24 hours. |
| Pediatric use | For adolescents 12-17 years: 5 mg or 10 mg orally at onset; maximum 20 mg in 24 hours (two doses with at least 2 hours between). Safety and efficacy in children <12 years not established. |
| Geriatric use | Limited data; initiate at 5 mg dose. Consider lower maximum total daily dose due to potential reduced clearance and increased sensitivity. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for MAXALT (MAXALT).
| Breastfeeding | Excreted in breast milk (M/P ratio unknown). Limited data; due to potential for adverse effects (e.g., diarrhea, irritability) in infants, use with caution, especially in preterm neonates. Consider alternative triptans with more lactation data (e.g., sumatriptan). |
| Teratogenic Risk | Pregnancy Category C. First trimester: No adequate human studies; animal studies show embryotoxicity (increased skeletal anomalies) at maternal toxic doses. Second and third trimesters: Risk of fetal serotonin syndrome with maternal use near term; potential for uterine hypertonus and decreased placental perfusion. Avoid unless benefit outweighs risk. |
■ FDA Black Box Warning
Maxalt is contraindicated in patients with ischemic heart disease, coronary artery vasospasm (including Prinzmetal's variant angina), or other significant underlying cardiovascular disease, and in patients with uncontrolled hypertension.
| Serious Effects |
["Ischemic heart disease (angina, history of myocardial infarction, silent ischemia)","Prinzmetal's angina (coronary artery vasospasm)","Peripheral vascular disease","Uncontrolled hypertension","History of stroke or transient ischemic attack","Use within 24 hours of another triptan or ergotamine-containing medication","Concomitant use of MAO-A inhibitors or use within 2 weeks of discontinuation","Severe hepatic impairment","Hemiplegic or basilar migraine"]
| Precautions | ["Risk of myocardial ischemia, infarction, and coronary artery vasospasm; do not use within 24 hours of another triptan or ergotamine","Serotonin syndrome risk, especially with SSRIs, SNRIs, tricyclic antidepressants, or MAO inhibitors","Increased blood pressure; contraindicated in uncontrolled hypertension","Risk of cerebrovascular events including stroke","Rebound headache with overuse","Severe hepatic impairment: contraindicated"] |
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| Fetal Monitoring | Monitor for fetal heart rate abnormalities if used during labor; assess for symptoms of serotonin syndrome (e.g., agitation, hyperthermia) in mother and neonate. No specific maternal-fetal monitoring required, but observe for uterine hypertonus and fetal distress if used near term. |
| Fertility Effects | No specific human studies; animal studies show no significant impairment of fertility. In theory, serotonin receptor agonism might affect reproductive hormone regulation, but clinical significance is unknown. Use is not contraindicated solely due to fertility concerns. |