Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ERGOSTAT vs APOMORPHINE HYDROCHLORIDE
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.
Non-ergoline dopamine agonist with high affinity for D2 and D3 receptors, moderate affinity for D4, D5, and adrenergic receptors; activates striatal dopamine receptors to improve motor function.
FDA-approved: Acute treatment of migraine headache with or without aura,Off-label: Cluster headache, vascular headache
FDA: Acute treatment of hypomobility episodes ('off' episodes) in Parkinson disease,Off-label: Refractory erectile dysfunction, treatment of levodopa-induced dyskinesias, depression
0.2 mg intramuscularly or intravenously every 2-4 hours for maximum 5 doses; not to exceed 1 mg total dose.
Subcutaneous injection: 0.2 m L (2 mg) test dose, then 0.2-0.6 m L (2-6 mg) as needed for acute hypomobility episodes; maximum single dose 0.6 m L (6 mg). Sublingual: 2-10 mg sublingually as needed, not more than every 2 hours, maximum 30 mg/day. Continuous subcutaneous infusion: 0.5-2.0 mg/hour via infusion pump.
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 elimination half-life is 40–60 minutes in adults with normal renal function; prolonged to 3–6 hours in end-stage renal disease.
Primarily hepatic via CYP3A4. Undergoes extensive first-pass metabolism.
Hepatic via CYP3A4, CYP2C9, and CYP2C19; main metabolite is apomorphine-8-O-sulfate; first-pass effect with rapid clearance.
Primarily hepatic (biliary-fecal) elimination: ~90% of a dose is excreted in feces as metabolites; renal excretion accounts for <5% unchanged drug.
Approximately 90% of an intravenous dose is excreted in urine within 24 hours, primarily as unchanged drug and sulfate conjugates. Biliary/fecal excretion is minimal (<5%).
~65% bound to plasma albumin. Metabolites are less extensively bound.
Approximately 90–99% bound, primarily to albumin.
Approximately 0.2–0.3 L/kg, indicating primarily extracellular and peripheral tissue distribution with limited CNS penetration.
1.8–2.5 L/kg, indicating extensive tissue distribution.
Oral: ~10–20% (extensive first-pass metabolism); Sublingual: ~50–60% (avoids portal circulation); Rectal: ~30–40% (variable).
Subcutaneous: 100% (absolute); sublingual: 16–18%; oral: <1% due to extensive first-pass metabolism.
No specific adjustment; use with caution in severe renal impairment (GFR <30 m L/min) due to potential accumulation.
No dose adjustment for mild to moderate impairment. Severe impairment (GFR <15 m L/min): avoid use as apomorphine is renally eliminated and accumulation may occur; use with caution and reduce dose if necessary at GFR 15-29 m L/min.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use.
Child-Pugh A and B: no dose adjustment necessary. Child-Pugh C: pharmacokinetics not studied; use with caution and monitor closely.
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.
Safety and efficacy not established; no pediatric dosing recommendations.
Start at 0.1 mg intramuscularly or intravenously; monitor for hypertension with higher doses.
Elderly patients may be more sensitive to neuropsychiatric effects; initiate at low end of dosing range (e.g., 1-2 mg subcutaneously) and titrate slowly; monitor for hypotension and falls.
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.
None.
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 hypotension, syncope, and orthostatic hypotension,Severe nausea and vomiting (pretreat with antiemetic),Potential for hallucination, dyskinesia, and impulse control disorders,Do not mix with serotonin 5-HT3 antagonists (e.g., ondansetron) due to severe hypotension,Use caution in patients with cardiovascular disease, hypotension, or renal impairment
Concurrent use of potent CYP3A4 inhibitors (e.g., boceprevir, clarithromycin, ketoconazole, ritonavir)
Concurrent use with serotonin 5-HT3 antagonists (e.g., ondansetron),Hypersensitivity to apomorphine or sulfite-containing products,Severe asthma or sulfite allergy
Avoid grapefruit juice as it may increase ergonovine levels. No other significant food interactions.
Avoid alcohol: may increase drowsiness and hypotension. Grapefruit juice: may increase risk of QT prolongation. No specific food interactions; maintain normal diet but monitor for changes in blood pressure.
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.
Apomorphine hydrochloride is a dopamine agonist indicated for Parkinson's disease. Limited human pregnancy data; animal studies show fetotoxicity and teratogenicity at doses near maternal toxic doses. FDA Pregnancy Category C. First trimester: Avoid use unless benefit outweighs risk. Second/third trimester: No established safety; potential fetal effects include altered dopamine receptor development. Postnatal: Risk of neonatal withdrawal if used near term.
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.
No data on apomorphine excretion in human milk. M/P ratio unknown. Due to potential for serious adverse reactions in breastfeeding infants (e.g., somnolence, hypotension, dyskinesia), breastfeeding is not recommended during therapy.
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.
Pregnancy can alter apomorphine pharmacokinetics due to increased plasma volume, renal blood flow, and hepatic metabolism. No specific dose adjustment guidelines exist. Use lowest effective dose with careful titration. Monitor for reduced efficacy or increased adverse effects (e.g., hypotension, nausea).
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.
Administer subcutaneously; avoid intravenous use due to risk of hemolytic anemia and hypotension. Onset is rapid (5-15 minutes) with short duration (1 hour). Use an antiemetic (e.g., domperidone or trimethobenzamide) for 3 days before starting to prevent nausea. Do not use with 5-HT3 antagonists (e.g., ondansetron) due to profound hypotension. Monitor for dyskinesia, orthostatic hypotension, and QT prolongation. Avoid in patients with dementia, psychosis, or severe respiratory depression; caution in hepatic/renal impairment. Test dose (0.2-0.5 m L) is required before first prescription.
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.
Take this medication exactly as prescribed; it is for on-demand treatment of 'off' episodes.,Inject under the skin (subcutaneous) as directed; do not inject into a vein or muscle.,You may feel dizzy or lightheaded when standing up; rise slowly from sitting or lying down.,Nausea is common; your doctor may prescribe an anti-nausea medicine to take before each dose.,Report any chest pain, fainting, or severe dizziness immediately.,Avoid alcohol and grapefruit juice while using this medication.,Do not change your dose or frequency without consulting your doctor.,Keep this medication away from children and pets.
No interactions on record
"Coadministration of morphine with palbociclib may increase plasma concentrations of palbociclib due to morphine-induced inhibition of intestinal P-glycoprotein (P-gp) efflux transporter and potential competition for CYP3A4 metabolism. This elevation can heighten the risk of palbociclib-related toxicities, including myelosuppression (neutropenia, leukopenia, anemia), hepatotoxicity, and gastrointestinal adverse effects (e.g., diarrhea, nausea). Patients should be monitored for signs of excessive palbociclib exposure and dose reductions considered if toxicity occurs."
"Morphine, a potent opioid analgesic, can inhibit the metabolism of sulfisoxazole, a sulfonamide antibiotic, by competing for hepatic glucuronidation pathways. This pharmacokinetic interaction leads to increased plasma concentrations of sulfisoxazole, potentially elevating the risk of dose-dependent adverse effects such as crystalluria, hypersensitivity reactions, and bone marrow suppression. Co-administration requires careful monitoring for sulfonamide toxicity, especially in patients with renal impairment or those receiving high-dose morphine."
"Morphine is a potent opioid analgesic that can inhibit the metabolism of isavuconazonium (prodrug of isavuconazole) via competitive inhibition of CYP3A4, the primary enzyme responsible for its activation. This leads to reduced conversion to the active antifungal isavuconazole, potentially decreasing its efficacy against invasive fungal infections. Conversely, isavuconazonium may also inhibit morphine metabolism, increasing opioid side effects such as respiratory depression, sedation, and constipation."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ERGOSTAT vs APOMORPHINE HYDROCHLORIDE, 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.. APOMORPHINE HYDROCHLORIDE is a Opioid Agonist that works by Non-ergoline dopamine agonist with high affinity for D2 and D3 receptors, moderate affinity for D4, D5, and adrenergic receptors; activates striatal dopamine receptors to improve motor function.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ERGOSTAT and APOMORPHINE HYDROCHLORIDE 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 APOMORPHINE HYDROCHLORIDE is: Subcutaneous injection: 0.2 m L (2 mg) test dose, then 0.2-0.6 m L (2-6 mg) as needed for acute hypomobility episodes; maximum single dose 0.6 m L (6 mg). Sublingual: 2-10 mg sublingually as needed, not more than every 2 hours, maximum 30 mg/day. Continuous subcutaneous infusion: 0.5-2.0 mg/hour via infusion pump.. 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 APOMORPHINE HYDROCHLORIDE 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. APOMORPHINE HYDROCHLORIDE is classified as Category D/X. Apomorphine hydrochloride is a dopamine agonist indicated for Parkinson's disease. Limited human pregnancy data; animal studies show fetotoxicity and teratogenicity at doses near m. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.