AXERT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AXERT (AXERT).
Selective serotonin 5-HT1B/1D receptor agonist; causes vasoconstriction of intracranial blood vessels and inhibits trigeminal nerve activation and release of vasoactive neuropeptides.
| Metabolism | Primarily hepatic via CYP1A2 and monoamine oxidase (MAO-A); forms inactive metabolites. |
| Excretion | Approximately 57% of a dose is excreted in urine (10-15% unchanged, remainder as metabolites) and 38% in feces (primarily as metabolites) via biliary elimination. |
| Half-life | Terminal elimination half-life is approximately 26 hours (range 20-30 hours), supporting once-daily dosing for sustained antimigraine effect. |
| Protein binding | Approximately 85% bound to plasma proteins (primarily albumin and alpha-1-acid glycoprotein). |
| Volume of Distribution | Volume of distribution is approximately 7-8 L/kg (500-600 L), indicating extensive extravascular distribution (e.g., lung, liver, kidney). |
| Bioavailability | Oral bioavailability is 40-50% (due to first-pass metabolism); absolute bioavailability is 47%. |
| Onset of Action | Oral: Onset of headache relief occurs within 20-40 minutes; therapeutic effect peaks at 2 hours. |
| Duration of Action | Duration of action is 6-12 hours for headache relief; may be shorter if residual aura persists. Repeat dosing not recommended within 2 hours of initial dose. |
AXERT (almotriptan malate) is administered orally. The recommended adult dose is 6.25 mg or 12.5 mg as a single tablet. If headache recurs, the dose may be repeated after 2 hours, with a maximum of 2 doses per 24-hour period (not exceeding 25 mg per day).
| Dosage form | TABLET |
| Renal impairment | For patients with severe renal impairment (CrCl < 30 mL/min), maximum dose is 6.25 mg per 24-hour period. No adjustment is needed for mild to moderate impairment (CrCl ≥ 30 mL/min). |
| Liver impairment | Contraindicated in patients with severe hepatic impairment (Child-Pugh Class C). In patients with moderate hepatic impairment, maximum dose is 6.25 mg per 24-hour period. No adjustment is required for mild impairment. |
| Pediatric use | Safety and efficacy in pediatric patients have not been established; use is not recommended in children (< 18 years of age). |
| Geriatric use | In elderly patients (≥ 65 years), dose selection should be cautious, usually starting at the low end of the dosing range (6.25 mg), reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AXERT (AXERT).
| Breastfeeding | Almotriptan is excreted into human breast milk in low amounts. Milk-to-plasma ratio is approximately 0.4. Limited data suggest relative infant dose is <1% of maternal weight-adjusted dose. Caution should be exercised; monitor infant for diarrhea, vomiting, or somnolence. |
| Teratogenic Risk | AXERT (almotriptan) is classified as pregnancy category C. Limited human data; animal studies showed fetal abnormalities at high doses. Risk cannot be ruled out. Use only if potential benefit justifies potential risk to fetus. - First trimester: No adequate human studies; avoid if possible. - Second trimester: Limited data; no established association with major malformations. - Third trimester: Potential for uterine hypertonus and reduced placental blood flow; may affect fetal oxygenation. |
■ FDA Black Box Warning
None
| Serious Effects |
["Ischemic heart disease (angina, history of MI, silent ischemia)","Coronary artery vasospasm (Prinzmetal's angina)","Other significant underlying cardiovascular disease","Uncontrolled hypertension","Hemiplegic or basilar migraine","Within 24 hours of another triptan or ergotamine-containing drug","Concurrent use or within 2 weeks of MAO-A inhibitor","Severe hepatic impairment","Hypersensitivity to almotriptan or any component"]
| Precautions | ["Risk of myocardial ischemia, infarction, and coronary artery vasospasm","Risk of cerebral hemorrhage, subarachnoid hemorrhage, and stroke","Risk of serotonin syndrome when used with other serotonergic drugs","Risk of medication overuse headache","Blood pressure increase, including hypertensive crisis","Asymptomatic ventricular arrhythmias have been reported","Risk of cardiac events in patients with Wolff-Parkinson-White syndrome or other accessory pathway conduction disorders","Risk of transient blindness and partial vision loss"] |
| Food/Dietary | No specific food interactions; avoid tyramine-rich foods if associated with migraine triggers. |
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| Fetal Monitoring | Monitor fetal heart rate and uterine activity during administration in late pregnancy. Assess for signs of fetal distress, especially in third trimester. No routine monitoring is required outside of standard prenatal care. |
| Fertility Effects | No significant effects on fertility were observed in animal studies. Human data are insufficient to determine effects on male or female fertility. |
| Clinical Pearls | First-line triptan for migraine with high oral bioavailability (70-90%). Onset of action within 30 minutes. Avoid in patients with hemiplegic or basilar migraine. Do not use within 24 hours of another triptan or ergotamine. |
| Patient Advice | Take one tablet at the first sign of migraine headache; do not exceed two tablets in 24 hours. · May cause dizziness, drowsiness, or fatigue; avoid driving or operating machinery until effects are known. · Seek emergency care if chest pain, palpitations, or severe abdominal pain occurs. · Report any sensation of tingling, flushing, or pressure; these are common and usually mild. · Avoid alcohol during use as it may worsen headache or side effects. |