Vincristine is a vinca alkaloid, a potent antineoplastic agent derived from the Madagascar periwinkle plant (Catharanthus roseus). It is a cell cycle-specific chemotherapeutic drug that binds to tubulin, inhibiting microtubule formation, thereby arresting mitosis in metaphase. It is a critical component of combination chemotherapy regimens for various hematological malignancies and solid tumors. In India, it is a Schedule G drug, available as a lyophilized powder for injection, and is a mainstay in both public and private oncology settings.
Adult: 1.4 mg/m² body surface area (BSA), administered intravenously. Maximum single dose is typically capped at 2 mg. Doses are usually given weekly or as per specific protocol (e.g., every 2 weeks in ABVD).
Note: For IV use only. Administer as a slow intravenous push over 1 minute, or as a short infusion (5-10 minutes) into the side port of a free-flowing IV line with normal saline. MUST be administered by personnel trained in handling vesicants. Flush line thoroughly before and after administration. Monitor site closely for extravasation.
Vincristine binds with high affinity to the beta-subunit of tubulin dimers, inhibiting their polymerization into microtubules. This disrupts the dynamic assembly and disassembly of the mitotic spindle during the M phase of the cell cycle, leading to metaphase arrest and subsequent apoptotic cell death. It also disrupts other microtubule-dependent functions, including axonal transport in neurons, which accounts for its neurotoxicity.
Pregnancy: FDA Pregnancy Category D. There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience. Avoid in pregnancy, especially during the first trimester. Can cause fetal harm. Effective contraception is required during and after treatment.
Driving: Patients should be cautioned against driving or operating heavy machinery, as vincristine can cause dizziness, weakness, and sensory/motor neuropathy, impairing physical and mental abilities.
| Itraconazole, Ketoconazole, Posaconazole | Inhibit CYP3A4, increasing vincristine plasma concentrations and risk of severe neurotoxicity (including paralytic ileus). | Major |
| Phenytoin, Carbamazepine, Phenobarbital | Induce CYP3A4, potentially decreasing vincristine efficacy. | Moderate |
| Erythromycin, Clarithromycin | Inhibit CYP3A4, increasing vincristine toxicity. | Major |
| L-Asparaginase | If given before vincristine, may reduce hepatic clearance of vincristine, increasing toxicity. Vincristine should be given 12-24 hours BEFORE L-asparaginase. | Major |
| Mitomycin-C | Increased risk of pulmonary toxicity. | Moderate |
| Digoxin | Vincristine may reduce digoxin absorption. | Moderate |
| Calcium Channel Blockers (e.g., Verapamil) | May inhibit P-glycoprotein, increasing vincristine concentrations. | Moderate |
Same composition (Vincristine (1mg)), different brands: