Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
AMIKIN vs Ergometrine / Methylergonovine
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Aminoglycoside antibiotic that binds to the 30S ribosomal subunit, causing misreading of m RNA and inhibition of protein synthesis.
Ergometrine and methylergonovine are ergot alkaloids that act as partial agonists at alpha-adrenergic, dopaminergic, and serotonergic (5-HT2) receptors. Their primary uterotonic effect is mediated by stimulation of 5-HT2 receptors in uterine smooth muscle, leading to sustained contractions and vasoconstriction.
Treatment of serious gram-negative bacterial infections,Infections caused by susceptible strains of Pseudomonas aeruginosa, Escherichia coli, Proteus, Klebsiella, Serratia, and Enterobacter
Prevention and treatment of postpartum hemorrhage (FDA approved),Uterine atony (FDA approved),Ovarian hyperstimulation syndrome (off-label),Variceal bleeding (off-label),Migraine headache (off-label)
15 mg/kg/day IV or IM divided every 8 to 12 hours; usual adult dose: 15 mg/kg/day
0.2 mg intramuscularly or intravenously, repeated every 2-4 hours as needed, up to 5 doses total. Maximum single dose: 0.5 mg. Maximum total dose: 1 mg.
2-3 hours in adults with normal renal function; prolonged to 30-90 hours in ESRD.
30-120 min (biphasic: initial 10 min, terminal 30-120 min); clinical context: short half-life allows repeated dosing for postpartum hemorrhage but requires monitoring for accumulation
Amikacin is not metabolized; it is excreted unchanged primarily by glomerular filtration.
Primarily hepatic via CYP3A4; also undergoes first-pass metabolism. Metabolites are excreted in urine and bile.
Renal: >90% unchanged in urine via glomerular filtration; biliary/fecal: <1%.
Renal (20% unchanged), biliary/fecal (35% as metabolites and parent compound)
0-10% (low binding to albumin).
85-90% (primarily to albumin and α1-acid glycoprotein)
0.25 L/kg in adults; higher in neonates and edema states (0.3-0.4 L/kg), indicating distribution into extracellular fluid.
0.4-0.6 L/kg; clinical meaning: moderate tissue distribution, consistent with limited extravascular binding
IM: 100% (complete absorption); oral: <1% (not absorbed).
Oral: 20-40% (due to extensive first-pass metabolism); IM: ~80%
GFR 30-59 m L/min: extend dosing interval to every 12-24 hours; GFR 15-29 m L/min: extend to every 24-48 hours; GFR <15 m L/min: extend to every 48-72 hours or consider peritonitis dosing; adjust based on serum levels
No specific guidelines; use with caution in severe renal impairment (GFR <30 m L/min) due to risk of accumulation and hypertensive effects.
No specific Child-Pugh based adjustments required; amikacin is minimally hepatically metabolized; monitor renal function as primary clearance route
Child-Pugh Class A: no adjustment. Child-Pugh Class B: reduce dose by 50% or extend interval. Child-Pugh Class C: avoid use.
Neonates: 15-20 mg/kg/day IV/IM every 12-24 hours depending on gestational age; Infants and children: 15-22.5 mg/kg/day divided every 8-12 hours; maximum 1.5 g/day
0.1-0.2 mg intramuscularly or intravenously every 2-4 hours as needed; maximum single dose 0.2 mg. For postpartum hemorrhage, 0.2 mg IM/IV repeated every 2-4 hours, max 5 doses.
Start with lower initial doses based on renal function; monitor renal function and serum amikacin levels closely; usual initial dose reduction to 7.5 mg/kg every 12-24 hours based on estimated GFR
Use lowest effective dose due to increased sensitivity and higher risk of hypertension and coronary vasospasm; consider 0.1 mg initially and titrate cautiously.
Amikacin can cause nephrotoxicity and ototoxicity. The risk of nephrotoxicity is greater in patients with impaired renal function and those receiving high doses or prolonged therapy. Ototoxicity (both vestibular and auditory) can occur in patients with pre-existing renal damage and in those with normal renal function treated with higher doses or for longer periods than recommended.
Concurrent use with potent CYP3A4 inhibitors (e.g., macrolide antibiotics, protease inhibitors, azole antifungals) may result in acute ergot toxicity (vasospasm, cerebral and peripheral ischemia). Contraindicated in pregnancy for induction of labor due to risk of uterine rupture and fetal harm.
Neurotoxicity (ototoxicity) and nephrotoxicity; neuromuscular blockade; respiratory paralysis; cross-allergenicity among aminoglycosides; monitoring of renal function and drug levels recommended.
May cause hypertension, especially in patients with preeclampsia or hypertension. Use with caution in patients with sepsis, hepatic or renal impairment, coronary artery disease, or peripheral vascular disease. Avoid prolonged use. Monitor uterine tone and bleeding.
Hypersensitivity to amikacin or any aminoglycoside; history of ototoxicity with prior aminoglycoside use.
Pregnancy (except for postpartum hemorrhage), hypertension, preeclampsia, eclampsia, coronary artery disease, peripheral vascular disease, Raynaud's phenomenon, sepsis, hypersensitivity to ergot alkaloids, concurrent use of potent CYP3A4 inhibitors.
No significant food interactions. Maintain adequate hydration. Avoid alcohol as it may worsen side effects.
No known food interactions.
Amikacin is an aminoglycoside antibiotic. There are no adequate and well-controlled studies in pregnant women. Animal studies have shown evidence of fetal harm (e.g., nephrotoxicity, ototoxicity) at doses similar to or lower than human doses. Amikacin crosses the placenta. First trimester: Risk cannot be excluded; use only if clearly needed. Second and third trimesters: Potential for fetal nephrotoxicity and ototoxicity; avoid use unless necessary for serious infections. Risk category D (positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience).
First trimester: Limited human data; animal studies show embryotoxicity and fetotoxicity at high doses due to uterotonic effects, but no structural malformations. Increased risk of spontaneous abortion from uterine hyperstimulation. Second trimester: Uterotonic effects may cause placental abruption, preterm labor, or fetal hypoxia. Third trimester: Contraindicated due to potent uterotonic activity; can cause uterine tetany, fetal distress, and stillbirth. Avoid during pregnancy unless for postpartum hemorrhage.
Amikacin is excreted into human breast milk in low concentrations. The milk-to-plasma (M/P) ratio is approximately 0.1-0.2. After intramuscular administration of 500 mg, peak milk concentrations are about 1-2 mcg/m L. Because of low oral bioavailability (poorly absorbed from the GI tract), systemic effects in the nursing infant are unlikely. However, theoretical risk of alteration of infant gut flora and direct exposure. Use with caution, especially in premature infants or those with renal impairment. The American Academy of Pediatrics considers amikacin compatible with breastfeeding.
Ergometrine and methylergonovine are excreted into breast milk in small amounts; M/P ratio estimated at 0.2-0.3. Milk concentrations are low (approximately 1-2% of maternal weight-adjusted dose). The American Academy of Pediatrics considers use compatible with breastfeeding, but may cause ergotism in infants (vomiting, diarrhea, seizures) with prolonged use. Short-term use for postpartum hemorrhage is generally acceptable.
Pharmacokinetic changes during pregnancy (e.g., increased volume of distribution, increased renal clearance) may require dose adjustments, but specific guidelines are not established. Generally, standard dosing based on actual body weight and renal function is used. Therapeutic drug monitoring is recommended, especially in third trimester or with concurrent renal impairment. Dose adjustments should be based on serum levels to maintain therapeutic efficacy while minimizing toxicity. No dose reduction is universally recommended; individualize based on renal function and clinical response.
No dose adjustment required for pregnancy because drug is contraindicated during pregnancy due to uterotonic effects. In postpartum use (which is the approved indication), no pharmacokinetic changes necessitate dose adjustment; normal adult dosing applies (0.2 mg IM/IV for ergometrine, 0.2 mg IM for methylergonovine).
Monitor peak (20-30 mcg/m L) and trough (1-8 mcg/m L) serum levels; adjust dose based on renal function. Avoid concurrent use with other ototoxic/nephrotoxic drugs. Use extended-interval dosing (e.g., 15-20 mg/kg IV once daily) when possible. Assess for vestibular toxicity (ataxia, vertigo) and cochlear toxicity (tinnitus, high-frequency hearing loss).
Administer intramuscularly or intravenously (slow push over 1 minute) for uterine atony; avoid in hypertension, preeclampsia, and sepsis. Store ampules protected from light; discard if discolored. Contraindicated in impaired hepatic or renal function.
Report any hearing loss, ringing in ears, dizziness, or unsteadiness immediately.,Drink plenty of fluids to help prevent kidney damage.,Avoid taking other aminoglycosides or strong diuretics unless prescribed.,Inform your doctor if you have kidney disease, myasthenia gravis, or are pregnant.
This medication may cause nausea, vomiting, or headache.,Report severe abdominal pain, chest pain, or difficulty breathing immediately.,Avoid driving or operating machinery if dizziness occurs.,Do not use during pregnancy except for postpartum hemorrhage.,Inform your doctor if you have high blood pressure, heart disease, or are breastfeeding.
No interactions on record
"Coadministration of bromocriptine, a dopamine D2 receptor agonist with vasoconstrictive properties, and ergometrine, an ergot alkaloid that acts as a partial agonist at alpha-adrenergic and serotonin receptors, synergistically increases peripheral vasoconstriction. This additive effect can lead to severe hypertension, myocardial ischemia, cerebral vasospasm, and potentially life-threatening ergotism. Patients may present with headache, chest pain, altered mental status, or peripheral ischemia."
"Nylidrin, a beta-adrenergic agonist, and ergometrine, an ergot alkaloid with vasoconstrictive properties, exhibit a synergistic hypertensive effect. By stimulating beta-2 receptors, nylidrin may cause peripheral vasodilation and reflex tachycardia, while ergometrine induces vasoconstriction via alpha-adrenergic and serotonin receptor activation. This opposing mechanism can lead to unopposed vasoconstriction, potentially resulting in severe hypertension, myocardial ischemia, or stroke."
"Simvastatin, a HMG-CoA reductase inhibitor, may increase the serum concentration of ergometrine, an ergot alkaloid used for postpartum hemorrhage, by inhibiting its metabolism via CYP3A4. This can lead to enhanced vasoconstrictive effects of ergometrine, potentially causing severe hypertension, myocardial ischemia, or peripheral vasospasm. Concomitant use poses a risk of ergotism, manifesting as ischemic complications, and should be approached with caution."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about AMIKIN vs Ergometrine / Methylergonovine, answered by our medical review team.
AMIKIN is a Aminoglycoside Antibiotic that works by Aminoglycoside antibiotic that binds to the 30S ribosomal subunit, causing misreading of m RNA and inhibition of protein synthesis.. Ergometrine / Methylergonovine is a Ergot Alkaloid Uterotonic that works by Ergometrine and methylergonovine are ergot alkaloids that act as partial agonists at alpha-adrenergic, dopaminergic, and serotonergic (5-HT2) receptors. Their primary uterotonic effect is mediated by stimulation of 5-HT2 receptors in uterine smooth muscle, leading to sustained contractions and vasoconstriction.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between AMIKIN and Ergometrine / Methylergonovine 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 AMIKIN is: 15 mg/kg/day IV or IM divided every 8 to 12 hours; usual adult dose: 15 mg/kg/day. The standard adult dose of Ergometrine / Methylergonovine is: 0.2 mg intramuscularly or intravenously, repeated every 2-4 hours as needed, up to 5 doses total. Maximum single dose: 0.5 mg. Maximum total dose: 1 mg.. 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 AMIKIN and Ergometrine / Methylergonovine 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. AMIKIN is classified as Category C. Amikacin is an aminoglycoside antibiotic. There are no adequate and well-controlled studies in pregnant women. Animal studies have shown evidence of fetal harm (e.g., nephrotoxicit. Ergometrine / Methylergonovine is classified as Category C. First trimester: Limited human data; animal studies show embryotoxicity and fetotoxicity at high doses due to uterotonic effects, but no structural malformations. Increased risk of. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.