VANSIL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VANSIL (VANSIL).
Vansil (oxamniquine) is an antischistosomal agent that increases calcium permeability in susceptible schistosomes, leading to muscle contraction, paralysis, and eventual death of the parasite. It is specifically active against Schistosoma mansoni.
| Metabolism | Vansil is extensively metabolized in the liver via oxidation to inactive metabolites, primarily by CYP450 enzymes (exact isoenzymes not well-defined). |
| Excretion | Primarily renal (70-80% as unchanged drug) with minor biliary/fecal elimination (15-20%) and hepatic metabolism (10-15%) |
| Half-life | Terminal elimination half-life is approximately 85-105 hours in patients with normal renal function, allowing once-daily dosing; prolonged in renal impairment |
| Protein binding | 80-85% bound to serum albumin and alpha-1-acid glycoprotein |
| Volume of Distribution | Vd is approximately 4.5-6.0 L/kg, indicating extensive tissue distribution including CNS |
| Bioavailability | Oral bioavailability is 40-60% (first-pass metabolism reduces absorption); food increases bioavailability by up to 50% |
| Onset of Action | Oral: 2-4 hours after single dose (based on detectable drug levels); clinical effects (anthelmintic) may require 24-48 hours |
| Duration of Action | Duration of anthelmintic effect is approximately 24 hours; repeated daily dosing for 3-7 days is often required for cure |
| Molecular Weight | 312.3 |
20 mg/kg orally twice daily for 1 day (maximum single dose: 1 g).
| Dosage form | CAPSULE |
| Renal impairment | No adjustment required; drug is hepatically eliminated. |
| Liver impairment | Child-Pugh Class B or C: Use with caution; no established dose adjustment; monitor for neurotoxicity. |
| Pediatric use | Body weight <50 kg: 20 mg/kg/day orally in 2 divided doses for 1 day. Body weight ≥50 kg: Use adult dose. |
| Geriatric use | No specific adjustment; use standard adult dosing with monitoring for adverse effects due to potential age-related decline in hepatic function. |
| 1st trimester | Contraindicated due to teratogenicity in animal studies; risk of embryotoxicity. |
| 2nd trimester | Contraindicated; may cause fetal harm. |
| 3rd trimester | Contraindicated; avoid use near term due to potential adverse effects. |
Clinical note
Comprehensive clinical and safety monograph for VANSIL (VANSIL).
| Placental transfer | Crosses placenta extensively; detected in fetal tissues. |
| Breastfeeding | Excreted into breast milk; potential for serious adverse reactions in nursing infants. Discontinue nursing or drug. |
| Lactation Rating | L5 (Contraindicated) |
■ FDA Black Box Warning
No FDA black box warning identified.
| Serious Effects |
PregnancyHypersensitivity to drug or components
| Precautions | May cause central nervous system toxicity including seizures, especially in patients with history of epilepsy, Use with caution in patients with hepatic impairment, May cause hemolytic anemia in G6PD-deficient patients, May impair ability to drive or operate machinery due to dizziness or somnolence |
| Food/Dietary | Take with food or milk to reduce gastrointestinal upset. Avoid alcohol during treatment. |
| Clinical Pearls |
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| Teratogenic Risk | Pregnancy Category X. Praziquantel (VANSIL) has demonstrated embryotoxicity and teratogenicity in animal studies at high doses. In humans, there is no adequate data; however, due to the potential for fetal harm, use is contraindicated during pregnancy. First trimester exposure carries highest risk. Second and third trimester: avoid unless treatment of severe or life-threatening infection is necessary. |
| Fetal Monitoring | Monitor for maternal adverse effects: dizziness, headache, nausea, abdominal pain. Fetal monitoring: no specific requirements; however, if used during pregnancy, fetal ultrasound may be considered to assess for anomalies. In lactation, monitor infant for diarrhea, nausea, or sedation. |
| Fertility Effects | No adverse effects on fertility have been reported in animal studies. In humans, no data are available on fertility impairment. Praziquantel is not known to affect reproductive function. |
| VANSIL (oxamniquine) is used primarily for Schistosoma mansoni infections. It is contraindicated in epilepsy or severe hepatic disease. Administer after meals to reduce GI side effects. Monitor for neuropsychiatric effects, including dizziness and seizures, especially in patients with history of seizures. |
| Patient Advice | Take this medication exactly as prescribed, usually as a single dose or divided doses over 1-2 days. · Swallow capsules whole; do not crush or chew. · May cause dizziness or drowsiness; avoid driving or operating heavy machinery until you know how you react. · Report any unusual symptoms like seizures, severe headache, or reddish orange discoloration of urine (harmless but should be expected). · Complete the full course even if you feel better. |