SANSERT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for SANSERT (SANSERT).
SANSERT (methysergide maleate) is a serotonin receptor antagonist, primarily acting on 5-HT2 receptors. It also has weak agonist activity at 5-HT1 receptors. The antimigraine effect is thought to be due to its vasoconstrictor properties and inhibition of neurogenic inflammation.
| Metabolism | Hepatic metabolism primarily via CYP450 enzymes, exact isoforms not well defined. Main metabolite is methylergometrine (active). |
| Excretion | Primarily hepatic metabolism with biliary excretion; ~4% excreted unchanged in urine; remainder as metabolites in feces. |
| Half-life | Terminal elimination half-life is approximately 10 hours; clinical context: dosing every 8-12 hours maintains therapeutic levels. |
| Protein binding | Approximately 90% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Approximately 0.6 L/kg; indicates moderate distribution into tissues. |
| Bioavailability | Oral bioavailability is low (approximately 30%) due to extensive first-pass metabolism. |
| Onset of Action | Oral: clinical effect onset within 30-60 minutes (headache prophylaxis requires 1-2 weeks of continuous therapy). |
| Duration of Action | Duration of action: 8-12 hours for a single oral dose; continuous therapy required for prophylactic effect (weeks to months). |
2 mg orally three times daily; maximum 6 mg/day oral; typically started at 2 mg once daily and titrated over 2-4 weeks.
| Dosage form | TABLET |
| Renal impairment | No specific guidelines; use with caution in severe renal impairment (CrCl <30 mL/min) due to potential accumulation; monitor for adverse effects. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh class C); in mild-to-moderate (Child-Pugh A or B), reduce dose by 50% and monitor liver function. |
| Pediatric use | Not recommended for children under 6 years; for ages 6-12, 2 mg once daily, titrate to 2 mg twice daily if needed; for adolescents >12, same as adult dosing. |
| Geriatric use | Start at lower dose (2 mg once daily) due to increased sensitivity; titrate slowly; monitor for hypotension, sedation, and cognitive effects. Dose reduction may be needed. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for SANSERT (SANSERT).
| Breastfeeding | No data available on excretion into breast milk. M/P ratio unknown. Due to potential for serious adverse effects, breast-feeding is contraindicated while using SANSERT. |
| Teratogenic Risk | Category X. First trimester: Significant risk of congenital malformations, including fibrotic disorders. Second and third trimesters: Continued risk of fetal harm, including premature closure of ductus arteriosus and persistent pulmonary hypertension. Use contraindicated in pregnancy. |
| Fetal Monitoring |
■ FDA Black Box Warning
Fibrotic complications: Retroperitoneal fibrosis, pleuropulmonary fibrosis, and cardiac valvulopathy have occurred. Use for no longer than 6 months with a 1-month drug-free interval.
| Serious Effects |
Hypersensitivity to methysergide or ergot derivatives; pregnancy; lactation; coronary artery disease; peripheral vascular disease; severe hypertension; hepatic or renal impairment; fibrotic conditions; concurrent use with strong CYP3A4 inhibitors.
| Precautions | Fibrotic complications (retroperitoneal, pleuropulmonary, cardiac); coronary artery disease; cardiac valvulopathy; renal impairment; hepatic impairment; drug interactions with CYP3A4 inhibitors (e.g., macrolides, protease inhibitors); pregnancy category X; may cause ergotism symptoms. |
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| Monitor for uterine contractions, fetal heart rate, and signs of premature labor if inadvertent exposure occurs. Evaluate for fetal fibrotic changes via ultrasound. Assess for maternal retroperitoneal or pleuropulmonary fibrosis with baseline and periodic imaging. |
| Fertility Effects | May impair fertility due to its ergot alkaloid properties, potentially causing tubal spasm or altered ovarian function. Effects reversible upon discontinuation. |