Levamisole

# levamisole ## Overview - **Classification**: Anthelmintic; historically, immunomodulator. - **Mechanism**: Causes spastic paralysis in susceptible worms by stimulating their ganglionic and neuromuscular systems. Also modulates host immune responses. ## Primary Indications 1. **Anthelmintic** - Treatment of ascariasis (roundworm) and hookworm infections. 2. **Immunomodulator** - Historically used as an adjuvant in colon cancer and for other immune-related conditions, largely discontinued due to severe toxicity. ## Adult Dosing ### Standard Dosing **Ascariasis & Hookworm** - **Dose**: **150 mg** - **Frequency**: Single dose - **Route**: Oral - **Duration**: Single treatment ### Dose Adjustments - **Renal Impairment**: Use with caution. No specific dose adjustment guidelines. - **Hepatic Impairment**: Use with caution. Monitor liver function tests. - **Elderly Patients**: No specific dose adjustments, but monitor closely for adverse effects. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: Not recommended. - **Special Notes**: Limited data and high risk of toxicity. ### Infants (1-12 months) - **Dose**: Not typically recommended. - **Special Notes**: High toxicity risk; alternative agents preferred. ### Children (1-12 years) - **Dose**: **2.5 mg/kg** - **Frequency**: Single dose - **Maximum**: **150 mg** - **Special Notes**: Administer as a single oral dose. ### Adolescents (13-18 years) - **Dose**: **150 mg** - **Maximum**: **150 mg** ## Safety Information ### Contraindications - **Absolute**: Pre-existing blood dyscrasias (e.g., agranulocytosis, neutropenia). - **Absolute**: Hypersensitivity to levamisole. - **Absolute**: Concurrent alcohol consumption (disulfiram-like reaction). ### Common Adverse Effects - **Common (1-10%)**: Nausea, vomiting, abdominal pain, diarrhea. - **Common (1-10%)**: Headache, dizziness. - **Serious but Rare**: Agranulocytosis, leukopenia (life-threatening hematologic toxicity). - **Serious but Rare**: Encephalopathy, neurological symptoms (especially with repeated doses). - **Serious but Rare**: Disulfiram-like reaction with alcohol. ### Key Drug Interactions - **Alcohol**: Severe disulfiram-like reaction (flushing, vomiting, tachycardia). **Avoid concurrent use.** - **Phenytoin**: May increase phenytoin levels, leading to toxicity. Monitor phenytoin levels. - **Warfarin**: May potentiate anticoagulant effect. Monitor INR/PT. - **Bone marrow suppressants**: Increased risk of hematologic toxicity. ## Monitoring & Follow-up - **Before Treatment**: Complete Blood Count (CBC) with differential is recommended. - **During Treatment**: If repeated doses are clinically necessary (rare for anthelmintic use), monitor CBC with differential weekly. - **Clinical Signs**: Monitor for signs of infection (fever, sore throat) indicating agranulocytosis. Observe for neurological changes. ## Clinical Pearls - 💡 **Tip 1**: Levamisole's current primary clinical use is as a single-dose anthelmintic for specific parasitic infections. - 💡 **Tip 2**: Its historical immunomodulatory use, particularly in oncology, is largely superseded due to significant hematologic and neurologic toxicities. - 💡 **Tip 3**: Emphasize strict avoidance of alcohol during treatment and for at least **72 hours** after the last dose due to severe interaction. - 💡 **Tip 4**: Counsel patients on symptoms of agranulocytosis (e.g., fever, chills, sore throat) and to seek immediate medical attention. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.