BLACK BOX WARNING
- FATAL if given intrathecally — must be given IV only; administer in a dilute IV bag with overwrap labeled 'For IV Use Only — Fatal If Administered Intrathecally'
vincristine
Brand: Oncovin, Vincasar
⚠ BBW ISMP High Alert Prototype Drug
Drug Class: vinca alkaloid antineoplastic
Drug Family: antineoplastic
Subclass: prototype vinca alkaloid
Organ Systems: hematology-oncology
Mechanism of Action
Binds beta-tubulin, inhibiting tubulin polymerization and disrupting mitotic spindle formation; arrests cells in M phase metaphase; also disrupts axonal microtubule structure, causing peripheral neuropathy.
tubulin (beta-tubulin)
Indications
- ALL (cornerstone)
- Hodgkin and non-Hodgkin lymphoma
- multiple myeloma
- Wilms tumor
- neuroblastoma
- rhabdomyosarcoma
Contraindications
- vincristine hypersensitivity
- Charcot-Marie-Tooth disease (demyelinating neuropathy)
- intrathecal administration (FATAL — causes ascending paralysis and death)
Adverse Effects
Common
- peripheral neuropathy (dose-limiting, sensorimotor)
- constipation/ileus (autonomic neuropathy)
- alopecia
Serious
- severe peripheral neuropathy (dose-limiting)
- SIADH/hyponatremia
- ileus/bowel obstruction (autonomic neuropathy)
- inadvertent intrathecal injection (FATAL)
- jaw pain
Pharmacokinetics (ADME)
| Absorption | IV only |
| Distribution | large Vd; does not cross BBB (protects CNS from intrathecal inadvertent dosing's systemic effects but means intrathecal accidental overdose is fatal) |
| Metabolism | hepatic CYP3A4 and P-gp |
| Excretion | biliary/fecal (>80%); renal minor |
| Half-life | 19–155 hours (triphasic) |
| Onset | immediate (IV) |
| Peak | end of infusion |
| Duration | 3–4 week cycles |
| Protein Binding | 75% |
| Vd | very large |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| itraconazole/voriconazole/azole antifungals | CYP3A4 inhibition increases vincristine levels; severe peripheral neuropathy, SIADH | major |
| nifedipine | inhibits P-gp and CYP3A4; increases vincristine exposure | moderate |
Nursing Considerations
- CRITICAL SAFETY: Vincristine must ALWAYS be prepared and dispensed in a minibag for IV infusion — NEVER in a syringe — to prevent accidental intrathecal administration, which causes fatal ascending myeloencephalopathy.
- Monitor for peripheral neuropathy at each visit: assess deep tendon reflexes (loss of ankle reflex is an early sign), paresthesias, and strength; dose reductions or discontinuation may be required.
- Constipation from autonomic neuropathy is universal — prophylactic bowel regimen (stool softener + stimulant laxative) should be initiated with the first dose.
- Monitor for SIADH: daily weights, signs of fluid retention, and serum sodium.
Clinical Pearls
- Vincristine intrathecal injection is universally fatal — this represents one of the most important medication safety issues in oncology. ISMP recommends vincristine be prepared ONLY in minibags (never syringes) and labeled with a warning; this is a Joint Commission National Patient Safety Goal.
- Vincristine uniquely causes peripheral neuropathy (due to axonal tubulin disruption) rather than myelosuppression, distinguishing it from most cytotoxics — it can often be combined with myelosuppressive agents without additive bone marrow toxicity.
Safety Profile
Pregnancy contraindicated
Lactation avoid
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.