Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
APOMORPHINE HYDROCHLORIDE vs ERGOMAR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
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.
Ergotamine acts as a partial agonist at serotonin 5-HT1B and 5-HT1D receptors, causing vasoconstriction of cranial blood vessels. It also inhibits norepinephrine reuptake and has alpha-adrenergic blocking activity.
FDA: Acute treatment of hypomobility episodes ('off' episodes) in Parkinson disease,Off-label: Refractory erectile dysfunction, treatment of levodopa-induced dyskinesias, depression
Abortive treatment of acute migraine headaches with or without aura,Cluster headache
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.
Ergotamine tartrate 1-2 mg sublingually or orally at onset of migraine, then 1-2 mg every 30 minutes as needed, maximum 6 mg per attack and 10 mg per week.
Terminal elimination half-life is 40–60 minutes in adults with normal renal function; prolonged to 3–6 hours in end-stage renal disease.
Terminal elimination half-life is approximately 2-3 hours for ergotamine, but clinical effects may persist longer due to active metabolites (e.g., ergotamine's half-life is 2.4 hours; metabolites have half-lives up to 10 hours).
Hepatic via CYP3A4, CYP2C9, and CYP2C19; main metabolite is apomorphine-8-O-sulfate; first-pass effect with rapid clearance.
Primarily hepatic via CYP3A4; minor contributions from CYP2D6. Undergoes extensive first-pass metabolism.
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%).
Primarily hepatic metabolism with extensive biliary excretion; less than 5% excreted unchanged in urine. Fecal elimination accounts for approximately 30-40% of the dose as metabolites.
Approximately 90–99% bound, primarily to albumin.
90-95% bound to plasma proteins, primarily albumin.
1.8–2.5 L/kg, indicating extensive tissue distribution.
Approximately 0.4 L/kg (16-18 L in adults), indicating moderate tissue distribution.
Subcutaneous: 100% (absolute); sublingual: 16–18%; oral: <1% due to extensive first-pass metabolism.
Sublingual: ~40-50%; Oral: <10% due to extensive first-pass metabolism; Rectal: ~25-30%.
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.
GFR > 30 m L/min: No adjustment. GFR 10-30 m L/min: Caution; reduce dose by 50%. GFR < 10 m L/min: Contraindicated.
Child-Pugh A and B: no dose adjustment necessary. Child-Pugh C: pharmacokinetics not studied; use with caution and monitor closely.
Child-Pugh A: Caution; reduce dose by 50%. Child-Pugh B: Contraindicated. Child-Pugh C: Contraindicated.
Safety and efficacy not established; no pediatric dosing recommendations.
Not recommended for children under 12 years. Pediatric use not established; avoid use.
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.
Elderly patients are more sensitive to vasoconstriction; use lower initial dose (e.g., 1 mg) and monitor for adverse effects.
None.
Serious and/or life-threatening peripheral ischemia and vasospasm have been associated with the concomitant use of ergotamine with potent CYP3A4 inhibitors including protease inhibitors, macrolide antibiotics, and azole antifungals.
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
Risk of ischemic events (peripheral, cardiac, cerebral), fibrosis (retroperitoneal, pulmonary, cardiac), elderly patients (more sensitive to adverse effects), ergotism, drug interactions with CYP3A4 inhibitors, and prolonged use leading to medication-overuse headache.
Concurrent use with serotonin 5-HT3 antagonists (e.g., ondansetron),Hypersensitivity to apomorphine or sulfite-containing products,Severe asthma or sulfite allergy
Hypersensitivity to ergot alkaloids, peripheral vascular disease, coronary artery disease, uncontrolled hypertension, sepsis, hepatic or renal impairment, pregnancy, breastfeeding, concomitant use with potent CYP3A4 inhibitors, hemiplegic or basilar migraine.
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.
Avoid grapefruit and grapefruit juice as they inhibit CYP3A4, increasing ergotamine levels and risk of toxicity. No other significant food interactions.
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.
Ergotamine (ERGOMAR) is contraindicated in pregnancy due to its oxytocic properties and potential for uterine hyperstimulation, fetal hypoxia, and congenital anomalies. First trimester: Increased risk of spontaneous abortion and major malformations (e.g., limb defects, CNS abnormalities) based on case reports. Second and third trimesters: Uterine hypertonicity and decreased placental perfusion leading to fetal distress, preterm labor, and low birth weight. Use only if benefit outweighs risk and no alternative; avoid in all trimesters.
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.
Ergotamine is excreted into breast milk with a milk-to-plasma ratio of approximately 0.5-0.9. Potential for ergotism symptoms in infants (vomiting, diarrhea, seizures). It may also reduce milk production due to prolactin inhibition. Contraindicated during breastfeeding per manufacturer guidelines. If exposure occurs, monitor infant for symptoms and consider abrupt cessation.
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).
Pregnancy may alter ergotamine pharmacokinetics (increased plasma volume, renal clearance, hepatic metabolism), but no established dose adjustment guidelines. Standard doses may be ineffective or toxic due to variable absorption. Avoid use if possible; if necessary, lowest effective dose for shortest duration, with close monitoring for toxicity.
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.
Ergomar (ergotamine tartrate sublingual tablets) is a first-line abortive therapy for acute migraine attacks, but its use is limited by vasoconstrictive risks. Avoid in patients with coronary artery disease, hypertension, peripheral vascular disease, or pregnancy. Administer at the first sign of migraine; sublingual route offers rapid absorption. Concomitant use with potent CYP3A4 inhibitors (e.g., macrolides, protease inhibitors) is contraindicated due to risk of ergotism. Limit total dose to 6 mg per attack and 10 mg per week.
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.
Take one sublingual tablet at the first sign of migraine, placing it under the tongue to dissolve, and do not swallow.,Do not exceed 3 tablets per attack or 5 tablets per week; overuse can lead to serious side effects.,Seek immediate medical attention if you experience symptoms of ergotism like severe coldness, numbness, or pain in hands/feet, muscle cramps, chest pain, or rapid heartbeat.,Avoid grapefruit and grapefruit juice during treatment as it may increase the risk of side effects.,Inform your doctor if you are pregnant, breastfeeding, or have any history of heart disease, high blood pressure, or peripheral artery disease.
"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."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about APOMORPHINE HYDROCHLORIDE vs ERGOMAR, answered by our medical review team.
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.. ERGOMAR is a Ergot Alkaloid Antimigraine that works by Ergotamine acts as a partial agonist at serotonin 5-HT1B and 5-HT1D receptors, causing vasoconstriction of cranial blood vessels. It also inhibits norepinephrine reuptake and has alpha-adrenergic blocking activity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between APOMORPHINE HYDROCHLORIDE and ERGOMAR 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 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.. The standard adult dose of ERGOMAR is: Ergotamine tartrate 1-2 mg sublingually or orally at onset of migraine, then 1-2 mg every 30 minutes as needed, maximum 6 mg per attack and 10 mg per week.. 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 APOMORPHINE HYDROCHLORIDE and ERGOMAR 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. 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. ERGOMAR is classified as Category C. Ergotamine (ERGOMAR) is contraindicated in pregnancy due to its oxytocic properties and potential for uterine hyperstimulation, fetal hypoxia, and congenital anomalies. First trime. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.