NARATRIPTAN
Clinical safety rating
avoidContraindicated (not allowed)
Selective serotonin 5-HT1B/1D receptor agonist; binds to these receptors on intracranial blood vessels and trigeminal sensory neurons, causing vasoconstriction and inhibition of neuropeptide release, thereby reducing migraine-related inflammation and pain.
| Metabolism | Hepatic via cytochrome P450 (CYP) enzymes, primarily CYP3A4, with minor contribution from other isoforms. Metabolites are inactive. |
| Excretion | Renal: ~50% (metabolites and unchanged drug); Fecal: ~30%; Biliary: minor; unchanged naratriptan accounts for <10% of urinary recovery. |
| Half-life | Terminal elimination half-life is approximately 5–6 hours (range 4–8 hours), supporting a twice-daily dosing interval for acute migraine treatment and allowing once-daily dosing for menstrual migraine prophylaxis. |
| Protein binding | ~29% bound, primarily to albumin. |
| Volume of Distribution | Approximately 2.4 L/kg (range 1.8–3.0 L/kg), consistent with extensive tissue distribution beyond plasma. |
| Bioavailability | Oral: 74% (range 63–95%); subcutaneous: ~100% (but not marketed). |
| Onset of Action | Oral: 1–3 hours; subcutaneous: 10–20 minutes (not clinically available). |
| Duration of Action | Clinical effect lasts 24 hours for headache relief, with a lower rate of headache recurrence at 24 hours compared to sumatriptan (17–28% vs. 22–35%). |
| Molecular Weight | 335.44 |
2.5 mg orally at onset of migraine; may repeat after 4 hours if headache recurs, maximum 5 mg per day.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment recommended; however, use with caution in severe renal impairment (CrCl <15 mL/min) due to limited data. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh class C). In mild to moderate impairment (Child-Pugh A or B), maximum dose is 2.5 mg per day; do not exceed single dose of 2.5 mg. |
| Pediatric use | Safety and efficacy not established in patients under 18 years; no approved pediatric dosing guidelines. |
| Geriatric use | Use with caution due to potential for reduced hepatic and renal function; no specific dose adjustment recommended, but start at low end of dosing range (2.5 mg). |
| 1st trimester | Limited human data. Animal studies show no teratogenicity at clinically relevant doses. Use only if potential benefit justifies risk. |
| 2nd trimester | No evidence of harm in limited human studies. Use with caution due to potential vasoconstrictive effects on uteroplacental circulation. |
| 3rd trimester | Avoid due to potential for uterine vasoconstriction and neonatal adverse effects (e.g., hypotonia, cyanosis). |
Clinical note
Other 5-HT1 agonists can have additive effects Contraindicated in ischemic heart disease and uncontrolled hypertension.
| Placental transfer | Crosses the placenta; data suggest transfer limited due to high molecular weight and low lipophilicity. |
| Breastfeeding | Naratriptan is excreted into breast milk in low amounts. The relative infant dose is approximately 1.6% of the maternal weight-adjusted dose. No adverse effects have been reported in breastfed infants. Use with caution, especially in preterm or high-risk infants. |
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | FDA Pregnancy Category C. Animal studies show fetal toxicity (increased resorptions, skeletal anomalies) at maternotoxic doses. No adequate human studies. Avoid in first trimester unless benefit outweighs risk. Second/third trimester: limited data; use only if clearly needed. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate during use in pregnancy. For prolonged use, fetal growth assessment via ultrasound recommended. In lactation, monitor infant for sedation, poor feeding. |
| Fertility Effects | Limited data. Animal studies show no impairment of fertility at sub-toxic doses. In humans, no specific reports of impaired fertility; however, triptans may potentially affect ovarian function indirectly via vascular effects, though unlikely. |
■ FDA Black Box Warning
Naratriptan is contraindicated in patients with ischemic heart disease or coronary artery vasospasm due to risk of myocardial ischemia/infarction and cerebrovascular events.
| Common Effects | Dizziness |
| Serious Effects |
Ischemic heart diseaseHistory of stroke or transient ischemic attackUncontrolled hypertensionWolff-Parkinson-White syndromeHemiplegic or basilar migraineConcurrent use or within 24 hours of ergotamine derivativesSevere hepatic impairment
| Precautions | Cardiac events: risk of myocardial ischemia, infarction, and arrhythmias, Cerebrovascular events: stroke, subarachnoid hemorrhage, Serotonin syndrome: especially with concomitant serotonergic drugs, Medication overuse headache: chronic use can lead to daily headaches, Severe hepatic impairment: reduce dose or avoid, Severe renal impairment: contraindicated |
| Food/Dietary | No significant food interactions. However, grapefruit juice may theoretically increase naratriptan exposure via CYP1A2 inhibition; avoid concurrent intake of large quantities. Alcohol may exacerbate migraine symptoms and should be avoided during an attack. |
| Clinical Pearls | Naratriptan has a longer half-life (~6 hours) and higher oral bioavailability (70%) compared to sumatriptan, making it suitable for patients with prolonged migraine attacks or those requiring sustained relief. It is contraindicated in patients with a history of ischemic heart disease, cerebrovascular disease, or uncontrolled hypertension due to vasoconstrictive effects. Use within 4 hours of migraine onset for optimal efficacy; do not use for prophylaxis. Monitor for serotonin syndrome when co-administered with other serotonergic drugs. |
| Patient Advice | Take naratriptan at the first sign of migraine headache; do not use to prevent migraines. · Do not exceed one tablet (2.5 mg) within 24 hours; do not take more than 2 tablets in any 24-hour period. · Seek emergency medical attention if you experience chest pain, shortness of breath, or sudden severe abdominal pain after taking this medication. · Inform your doctor if you have heart disease, high blood pressure, liver or kidney problems, or if you are pregnant or breastfeeding. · Avoid using naratriptan within 24 hours of other triptans or ergotamine-containing medications. |
Loading safety data…