Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ERGOSTAT vs DIHYDROERGOTAMINE MESYLATE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Ergostat (ergotamine) is a serotonin (5-HT) receptor agonist, specifically at 5-HT1B and 5-HT1D receptors, leading to cranial vasoconstriction and inhibition of neurogenic inflammation. It also has partial agonist/antagonist activity at alpha-adrenergic receptors.
Dihydroergotamine mesylate is an ergot alkaloid with potent agonist activity at serotonin 5-HT1B/1D receptors, leading to vasoconstriction of cranial blood vessels. It also has partial agonist/antagonist activity at alpha-adrenergic and dopamine receptors, contributing to its antimigraine effects.
FDA-approved: Acute treatment of migraine headache with or without aura,Off-label: Cluster headache, vascular headache
Acute treatment of migraine headaches with or without aura (FDA-approved),Acute treatment of cluster headache episodes (off-label)
0.2 mg intramuscularly or intravenously every 2-4 hours for maximum 5 doses; not to exceed 1 mg total dose.
1 mg intramuscularly or subcutaneously, repeat at 1-hour intervals as needed, maximum 3 mg per 24 hours and 6 mg per week; intravenous use is reserved for severe cases: 0.5-1 mg IV, may repeat once after 1 hour, maximum 2 mg per 24 hours.
Terminal half-life is 2–3 hours (intravenous) and 2–4 hours (oral). Short half-life necessitates frequent dosing; duration of action limited to 2–4 hours.
Terminal half-life is approximately 9 hours (range 7-13 hours) after IM administration; clinical effect duration corresponds to this elimination phase.
Primarily hepatic via CYP3A4. Undergoes extensive first-pass metabolism.
Primarily hepatic via CYP3A4; undergoes first-pass metabolism. The main metabolite is 8'-hydroxy-dihydroergotamine, which is also active.
Primarily hepatic (biliary-fecal) elimination: ~90% of a dose is excreted in feces as metabolites; renal excretion accounts for <5% unchanged drug.
Primarily hepatic metabolism; <10% excreted unchanged in urine; biliary/fecal excretion accounts for ~90% of metabolites.
~65% bound to plasma albumin. Metabolites are less extensively bound.
Approximately 93% bound, primarily to serum albumin and alpha-1-acid glycoprotein.
Approximately 0.2–0.3 L/kg, indicating primarily extracellular and peripheral tissue distribution with limited CNS penetration.
Approximately 0.25-0.3 L/kg; indicates moderate tissue distribution with high affinity for vascular receptors.
Oral: ~10–20% (extensive first-pass metabolism); Sublingual: ~50–60% (avoids portal circulation); Rectal: ~30–40% (variable).
Intramuscular: ~30-40% (due to first-pass metabolism); intranasal: ~38-50% (relative to IM); oral: <1% (not clinically used orally).
No specific adjustment; use with caution in severe renal impairment (GFR <30 m L/min) due to potential accumulation.
Cr Cl <30 m L/min: contraindicated; Cr Cl 30-60 m L/min: use with caution, reduce dose by 50%; Cr Cl >60 m L/min: no adjustment needed.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use.
Child-Pugh Class A: reduce dose by 50%; Child-Pugh Class B: contraindicated; Child-Pugh Class C: contraindicated.
Intravenous: 0.1 mg/m² body surface area every 2-4 hours, maximum 0.5 mg total; intramuscular: 0.2 mg every 2-4 hours, maximum 1 mg.
Not recommended for patients under 12 years of age due to lack of safety data; for adolescents (12-17 years): 0.5-1 mg subcutaneously or intramuscularly, repeat at 1-hour intervals as needed, maximum 2 mg per 24 hours and 4 mg per week.
Start at 0.1 mg intramuscularly or intravenously; monitor for hypertension with higher doses.
Elderly patients may have increased sensitivity; initiate at 0.5 mg intramuscularly or subcutaneously, maximum 2 mg per 24 hours; monitor for adverse effects (e.g., vasospasm, ischemia).
Concomitant use with strong CYP3A4 inhibitors (e.g., protease inhibitors, macrolide antibiotics, azole antifungals) can lead to serious and/or life-threatening peripheral ischemia and vasospasm. Avoid coadministration.
Serious and/or life-threatening peripheral ischemia has been associated with the coadministration of dihydroergotamine with potent CYP3A4 inhibitors (including protease inhibitors, azole antifungals, and macrolide antibiotics).
Risk of ischemia (peripheral, cerebral, coronary) especially with prolonged use or overdose,Fibrotic complications (cardiac valvulopathy, pulmonary, retroperitoneal fibrosis) with chronic use,Medication overuse headache (MOH) with frequent use, Avoid in patients with uncontrolled hypertension, coronary artery disease, or peripheral vascular disease,Do not exceed recommended dosage; may cause ergotism
Risk of cerebral and peripheral vasospasm, especially with prolonged use or overdose,May cause ergotism (symptoms include numbness, tingling, cyanosis, and gangrene),Caution in patients with hypertension, coronary artery disease, or impaired hepatic/renal function,Avoid repeated administration within 24 hours due to risk of accumulation and toxicity
Concurrent use of potent CYP3A4 inhibitors (e.g., boceprevir, clarithromycin, ketoconazole, ritonavir)
Concurrent use with potent CYP3A4 inhibitors (e.g., protease inhibitors, azole antifungals, macrolides),Uncontrolled hypertension,Coronary artery disease, including angina or history of myocardial infarction,Peripheral vascular disease,Sepsis,Pregnancy (category X),Severe hepatic or renal impairment,History of hemiplegic or basilar migraine (due to risk of vasospasm)
Avoid grapefruit juice as it may increase ergonovine levels. No other significant food interactions.
Grapefruit juice may increase systemic exposure; avoid concurrent consumption. Alcohol may exacerbate headache or adverse effects.
Ergostat (ergonovine) is contraindicated in pregnancy due to its potent uterotonic effects, which can cause uterine tetany, fetal hypoxia, and placental abruption. It is classified as FDA Pregnancy Category X. Use in the first trimester may increase the risk of spontaneous abortion; in the second and third trimesters, it can precipitate preterm labor and fetal distress. There is no evidence of structural teratogenicity from direct drug effects, but the potential for ischemic injury to the fetus due to uterine hyperstimulation exists.
FDA Pregnancy Category X. Dihydroergotamine is contraindicated in all trimesters due to oxytocic effects and uterine hypertonicity risk. Case reports of fetal hypoxia, growth restriction, and malformations (including limb defects and neural tube defects) from ergot alkaloids. First trimester: increased risk of spontaneous abortion and congenital anomalies. Second and third trimesters: risk of preterm labor, fetal distress, and low birth weight due to uteroplacental insufficiency.
Ergonovine is excreted into breast milk. The M/P ratio is not well established, but small amounts are detectable. It may cause adverse effects in the nursing infant, including vomiting, diarrhea, and transient hypertension. Because of the risk of ergotism in the infant, breastfeeding is generally not recommended during therapy. A decision should be made to discontinue breastfeeding or discontinue the drug, considering the importance of the drug to the mother.
Contraindicated in breastfeeding. Dihydroergotamine is excreted in breast milk; M/P ratio unknown. Ergot alkaloids can cause vomiting, diarrhea, weak pulse, unstable blood pressure, and convulsions in infants. May also suppress lactation via prolactin inhibition.
No dosing adjustments are recommended or studied because use in pregnancy is contraindicated. If exposure occurs accidentally or for life-threatening indications (e.g., severe postpartum hemorrhage), the same doses used in non-pregnant adults (0.2 mg IM or IV) may be employed, but with extreme caution due to heightened sensitivity to uterotonic effects. No pharmacokinetic studies in pregnancy exist; however, increased plasma volume and altered hepatic metabolism may require careful titration, but no specific evidence supports dose changes.
Not applicable; contraindicated in pregnancy. No pharmacokinetic studies exist due to safety concerns. No dose adjustments are recommended as the drug should not be used.
ERGOSTAT (ergonovine) is an ergot alkaloid used for postpartum hemorrhage. It causes sustained uterine contraction. Contraindicated in hypertension, preeclampsia, and vascular disease. Administer IM or IV slowly over 1 minute to avoid severe vasoconstriction. Monitor blood pressure and uterine tone closely. Do not use in patients with hypersensitivity to ergot alkaloids.
Avoid use within 24 hours of other ergot alkaloids or triptans due to additive vasospasm risk. Administer at first sign of migraine aura or headache; may repeat after 1 hour (max 3 mg/day, 6 mg/week). Contraindicated in coronary artery disease, uncontrolled hypertension, and pregnancy. Intranasal route may cause rhinorrhea or nasal congestion.
This medication is given to control bleeding after childbirth.,It may cause nausea, vomiting, or dizziness.,Report severe headache, chest pain, or vision changes immediately.,Avoid smoking or using nicotine products while on this drug.,Do not breastfeed within 12 hours after the last dose; discuss with your doctor.
Use exactly as prescribed at the first sign of a migraine headache.,Do not exceed 3 mg in 24 hours or 6 mg in one week.,Seek emergency help if you experience signs of ergotism: severe muscle pain, cold or numb fingers/toes, or chest tightness.,Avoid grapefruit juice as it may increase drug levels.,Do not take with other migraine medications (triptans, other ergots) within 24 hours.,Report any chest pain, shortness of breath, or irregular heartbeat immediately.
No interactions on record
"Dihydroergotamine is a potent inhibitor of CYP3A4, the primary enzyme responsible for the metabolism of bortezomib. Co-administration can significantly decrease bortezomib clearance, leading to elevated plasma concentrations and increased risk of bortezomib-related toxicities, particularly peripheral neuropathy, thrombocytopenia, and hypotension. Clinicians should monitor for enhanced adverse effects and consider dose adjustments or alternative therapies."
"Seratrodast, a thromboxane A2 receptor antagonist, inhibits CYP3A4-mediated metabolism of dihydroergotamine, a vasoconstrictor ergot alkaloid. This results in elevated plasma dihydroergotamine concentrations, increasing the risk of ergotism (severe vasospasm, ischemia, and potential gangrene). Clinical outcomes may include hypertension, myocardial ischemia, and peripheral vascular compromise, particularly in patients with risk factors such as coronary artery disease or smoking."
"Dexchlorpheniramine maleate, a first-generation antihistamine with significant anticholinergic properties, may inhibit the metabolism of dihydroergotamine via competitive antagonism of cytochrome P450 (CYP) 3A4 isoenzymes. This interaction can lead to elevated plasma concentrations of dihydroergotamine, increasing the risk of ergotism (e.g., vasospasm, ischemia, gangrene) and hypertensive crisis. Clinically, patients may present with peripheral coldness, muscle pain, cyanosis, or severe hypertension, particularly with concurrent use or overdose."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ERGOSTAT vs DIHYDROERGOTAMINE MESYLATE, answered by our medical review team.
ERGOSTAT is a Ergot Alkaloid Antimigraine that works by Ergostat (ergotamine) is a serotonin (5-HT) receptor agonist, specifically at 5-HT1B and 5-HT1D receptors, leading to cranial vasoconstriction and inhibition of neurogenic inflammation. It also has partial agonist/antagonist activity at alpha-adrenergic receptors.. DIHYDROERGOTAMINE MESYLATE is a Ergot Alkaloid that works by Dihydroergotamine mesylate is an ergot alkaloid with potent agonist activity at serotonin 5-HT1B/1D receptors, leading to vasoconstriction of cranial blood vessels. It also has partial agonist/antagonist activity at alpha-adrenergic and dopamine receptors, contributing to its antimigraine effects.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ERGOSTAT and DIHYDROERGOTAMINE MESYLATE depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ERGOSTAT is: 0.2 mg intramuscularly or intravenously every 2-4 hours for maximum 5 doses; not to exceed 1 mg total dose.. The standard adult dose of DIHYDROERGOTAMINE MESYLATE is: 1 mg intramuscularly or subcutaneously, repeat at 1-hour intervals as needed, maximum 3 mg per 24 hours and 6 mg per week; intravenous use is reserved for severe cases: 0.5-1 mg IV, may repeat once after 1 hour, maximum 2 mg per 24 hours.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ERGOSTAT and DIHYDROERGOTAMINE MESYLATE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ERGOSTAT is classified as Category C. Ergostat (ergonovine) is contraindicated in pregnancy due to its potent uterotonic effects, which can cause uterine tetany, fetal hypoxia, and placental abruption. It is classified. DIHYDROERGOTAMINE MESYLATE is classified as Category D/X. FDA Pregnancy Category X. Dihydroergotamine is contraindicated in all trimesters due to oxytocic effects and uterine hypertonicity risk. Case reports of fetal hypoxia, growth restr. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.