Vincristine

# vincristine ## Overview - **Classification**: Mitotic inhibitor, Vinca alkaloid, Antineoplastic agent - **Mechanism**: Binds to tubulin, inhibiting microtubule polymerization, causing mitotic arrest at metaphase and resulting in cell death[1][2][3][6]. ## Primary Indications 1. **Acute lymphoblastic leukemia (ALL)** – Used in induction and combination chemotherapy regimens 2. **Non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma** – Part of multi-agent chemo protocols 3. **Other cancers** – Neuroblastoma, Wilms' tumor, Ewing sarcoma, rhabdomyosarcoma, small cell lung cancer, and others[1][3][6]. ## Adult Dosing ### Standard Dosing **Acute lymphoblastic leukemia, lymphoma, and other malignancies** - **Dose**: 1.4 mg/m² (max 2 mg per dose) - **Frequency**: Once weekly or as per protocol - **Route**: Intravenous (IV) infusion, slow push or infusion - **Duration**: Based on chemotherapy regimen ### Dose Adjustments - **Renal impairment**: No specific dosing adjustments recommended; use caution - **Hepatic impairment**: Reduce dose by 50% if bilirubin 1.5–3 mg/dL; consider withholding if bilirubin >3 mg/dL due to reduced metabolism and increased toxicity risk[1][6] - **Elderly patients**: No formal adjustment, but monitor closely for neurotoxicity ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: 0.01–0.05 mg/kg - **Frequency**: Weekly - **Maximum**: Usually capped at 0.05 mg/kg or 2 mg max - **Special Notes**: Careful monitoring due to immature liver function affecting metabolism ### Infants (1-12 months) - **Dose**: 0.05 mg/kg - **Frequency**: Weekly - **Maximum**: 2 mg per dose ### Children (1-12 years) - **Dose**: 1.5–2 mg/m² (max 2 mg) once weekly - **Frequency**: Weekly - **Maximum**: Adult dose equivalent (2 mg max) ### Adolescents (13-18 years) - **Dose**: Use adult dosing (1.4 mg/m², max 2 mg) - **Maximum**: 2 mg per dose ## Safety Information ### Contraindications - **Absolute**: Intrathecal administration (fatal if given intrathecally) - **Absolute**: Hypersensitivity to vincristine or any component - **Relative**: Pre-existing peripheral neuropathy or demyelinating conditions (e.g., Charcot-Marie-Tooth syndrome)[5] ### Common Adverse Effects - **Very Common (>10%)**: Peripheral neuropathy (sensory and motor), constipation/ileus - **Common (1-10%)**: Jaw pain, SIADH, mild myelosuppression (rare), phlebitis at injection site - **Serious but Rare**: Severe neurotoxicity (autonomic neuropathy, cranial nerve palsies), seizures, paralytic ileus, tumor lysis syndrome ### Key Drug Interactions - **CYP3A4 inhibitors (e.g., azole antifungals, macrolides)**: Increased vincristine toxicity; monitor closely for neurotoxicity - **P-glycoprotein inhibitors**: May increase vincristine levels; dose adjustment may be needed - **Other neurotoxic drugs (e.g., other vinca alkaloids, cisplatin)**: Increased risk of additive neuropathy ## Monitoring & Follow-up - **Before Treatment**: Baseline neurologic exam, liver function tests (LFTs), complete blood count (CBC) - **During Treatment**: Monitor neurologic status weekly, LFTs periodically, and bowel function - **Clinical Signs**: Watch for peripheral neuropathy signs, constipation/ileus, jaw pain, weakness ## Clinical Pearls - 💡 **Avoid intrathecal administration at all costs** — fatal neurotoxicity occurs - 💡 **Monitor liver function closely** to avoid toxicity, as vincristine is hepatically metabolized - 💡 **Counsel patients on constipation prevention** and neurologic symptoms to report early > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.