Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ERGAMISOL vs ANTEPAR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Levamisole is an anthelmintic and immunomodulator. It acts as a nicotinic acetylcholine receptor agonist at the neuromuscular junction in nematodes, causing spastic paralysis. Its immunomodulatory effects are thought to involve stimulation of T-cell activation and phagocytosis.
Piperazine, the active ingredient, causes paralysis of the parasite by blocking acetylcholine at the neuromuscular junction and altering muscle membrane ion permeability.
Adjuvant therapy in combination with fluorouracil for the treatment of Dukes' C colon cancer (FDA-approved, now discontinued),Off-label: treatment of steroid-resistant nephrotic syndrome in children, and as an adjuvant in melanoma and other cancers
Treatment of ascariasis (roundworm infection),Treatment of enterobiasis (pinworm infection)
150 mg orally once daily
Adult: 50-75 mg/kg/day orally in 3 divided doses for 3 days; maximum 3 g/day.
2-4 hours (terminal); prolonged in hepatic impairment (up to 8-12 hours) and renal impairment (increase by 1.5- to 2-fold).
Terminal elimination half-life is approximately 3-4 hours in patients with normal renal function; may be prolonged in renal impairment.
Hepatic metabolism primarily via CYP450 enzymes (CYP2B6 and CYP3A4) to active metabolites. Levamisole undergoes extensive biotransformation to its major metabolites, p-hydroxy-levamisole and levamisole sulfoxide.
Partially metabolized in the liver; some metabolites are excreted unchanged.
Renal (parent drug and metabolites): ~70% in urine; Fecal: ~25% primarily as metabolites; <5% unchanged in urine.
Renal elimination of unchanged drug and metabolites accounts for approximately 70-80%, with the remainder excreted in feces via biliary elimination.
20-30%, primarily to albumin.
Approximately 90% bound to plasma proteins, primarily albumin.
1.0-1.5 L/kg; indicates extensive tissue distribution, including penetration into liver and kidneys.
Volume of distribution is approximately 0.6-1.0 L/kg, indicating distribution into total body water.
Oral: 40-60% (extensive first-pass metabolism).
Oral bioavailability is approximately 80-90% due to extensive absorption with minimal first-pass metabolism.
GFR 30-60 m L/min: no adjustment; GFR <30 m L/min: not recommended
GFR 10-50 m L/min: administer 50-75% of normal dose; GFR <10 m L/min: administer 25-50% of normal dose; hemodialysis: administer after dialysis.
Child-Pugh A: no adjustment; Child-Pugh B or C: avoid use
Child-Pugh Class A: no adjustment; Class B: reduce dose by 25-50%; Class C: contraindicated or use with extreme caution, reduce dose by 75%.
2.5 mg/kg orally once daily; maximum 150 mg daily
Children: 10-20 mg/kg/day orally in 2 divided doses; maximum 750 mg/day for <10 kg, 1.5 g/day for 10-20 kg, 2.25 g/day for 20-40 kg, 3 g/day for >40 kg.
No specific adjustment; monitor for renal function and potential QT prolongation
Elderly: initiate at lower end of dosing range; monitor renal function and adjust dose accordingly; avoid in patients with significant hepatic impairment.
None specifically required for ergamisol (levamisole). However, use of levamisole as an immunomodulator has been associated with agranulocytosis and other severe hematologic reactions.
None.
Agranulocytosis (may occur weeks after initiation and is reversible upon discontinuation), hemolytic anemia (especially in patients with G6PD deficiency), neurologic effects (seizures, dizziness, headache), hepatotoxicity, and hypersensitivity reactions.
Caution in patients with epilepsy or impaired renal function; may cause neurotoxicity at high doses.
Known hypersensitivity to levamisole; patients with a history of agranulocytosis induced by levamisole; concomitant use with alcohol (disulfiram-like reaction); caution in patients with hepatic or renal impairment.
Hypersensitivity to piperazine; patients with pre-existing neurological disorders such as epilepsy.
Avoid alcohol during therapy due to potential disulfiram-like reaction (nausea, vomiting, flushing). No specific food restrictions; maintain adequate hydration. Grapefruit juice may inhibit CYP2C19 metabolism, potentially increasing levamisole levels; consider avoidance.
No significant food interactions reported. Avoid alcohol as it may increase CNS side effects. Take with food if gastrointestinal upset occurs.
Ergamisole (levamisole) is classified as FDA Pregnancy Category C. Animal studies have shown embryotoxicity and teratogenicity at doses comparable to human doses. There are no adequate and well-controlled studies in pregnant women. Use only if potential benefit justifies potential risk to fetus. In first trimester, avoid use; second and third trimester, use with caution if indicated.
ANTEPAR (piperazine citrate) is classified as FDA Pregnancy Category C. Animal studies have shown embryotoxic effects at high doses, but no well-controlled human studies exist. First trimester exposure may be associated with a slightly increased risk of congenital anomalies, though data are limited. Second and third trimester risks are not well-defined; use only if clearly needed.
Levamisole is excreted in human milk in low amounts; M/P ratio is not established. Because of potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
Piperazine is excreted into breast milk in small amounts. The M/P ratio is not established. The American Academy of Pediatrics considers piperazine compatible with breastfeeding, but caution is advised due to potential adverse effects in nursing infants. Use only if benefits outweigh risks.
Pharmacokinetics in pregnancy are not well characterized. No specific dose adjustments are recommended; however, due to potential for altered metabolism, use lowest effective dose and monitor maternal toxicity closely.
No specific dose adjustments recommended during pregnancy. Piperazine pharmacokinetics may be altered due to increased plasma volume and renal clearance, but standard dosing is generally used. Monitor for efficacy and adverse effects.
Levamisole (ERGAMISOL) is primarily used as an immunomodulator in adjuvant therapy for stage III colon cancer after surgical resection. It is often combined with fluorouracil. Monitor for agranulocytosis, especially in patients with poor metabolizer status of CYP2D6. Agranulocytosis can occur weeks to months after initiation; obtain baseline CBC and repeat periodically. Levamisole can cause a metallic taste and reversible ANCA-positive vasculitis. Avoid in patients with known hypersensitivity or bone marrow depression.
ANTEPAR (piperazine) is a first-line treatment for ascariasis and enterobiasis. It causes neuromuscular paralysis in worms via GABA receptor agonism. Contraindicated in epilepsy and renal impairment. Monitor for neurotoxicity (ataxia, confusion) especially in children. Effective against both adult and immature worms; no need for laxatives.
Take levamisole exactly as prescribed, usually for 3 days every 2 weeks for 1 year. Do not miss doses.,Report any signs of infection (fever, sore throat, mouth sores) immediately as it can lower white blood cell count.,You may experience a metallic taste; this is harmless and may resolve with time.,Avoid alcohol consumption as it may increase risk of adverse effects.,Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding.,Do not take any other medications or supplements without consulting your doctor.
Take exactly as prescribed; complete full course even if symptoms improve.,May cause dizziness or blurred vision; avoid driving until you know how the drug affects you.,Report any muscle weakness, tremors, or confusion to your doctor immediately.,For pinworm infection, all household members should be treated to prevent reinfection.,Practice strict hand hygiene and wash bed linens in hot water to reduce spread.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ERGAMISOL vs ANTEPAR, answered by our medical review team.
ERGAMISOL is a Anthelmintic Immunomodulator that works by Levamisole is an anthelmintic and immunomodulator. It acts as a nicotinic acetylcholine receptor agonist at the neuromuscular junction in nematodes, causing spastic paralysis. Its immunomodulatory effects are thought to involve stimulation of T-cell activation and phagocytosis.. ANTEPAR is a Anthelmintic that works by Piperazine, the active ingredient, causes paralysis of the parasite by blocking acetylcholine at the neuromuscular junction and altering muscle membrane ion permeability.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ERGAMISOL and ANTEPAR 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 ERGAMISOL is: 150 mg orally once daily. The standard adult dose of ANTEPAR is: Adult: 50-75 mg/kg/day orally in 3 divided doses for 3 days; maximum 3 g/day.. 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 ERGAMISOL and ANTEPAR 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. ERGAMISOL is classified as Category C. Ergamisole (levamisole) is classified as FDA Pregnancy Category C. Animal studies have shown embryotoxicity and teratogenicity at doses comparable to human doses. There are no adeq. ANTEPAR is classified as Category C. ANTEPAR (piperazine citrate) is classified as FDA Pregnancy Category C. Animal studies have shown embryotoxic effects at high doses, but no well-controlled human studies exist. Fir. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.