Plant Alkaloids
Key Points
- Plant alkaloids (for example vincristine, vinblastine, etoposide) disrupt mitosis and trigger tumor-cell death.
- Major toxicity is neurotoxicity, including peripheral neuropathy and severe constipation that can progress to paralytic ileus.
- These agents are myelosuppressive and can increase infection and bleeding risk.
- Vincristine is for intravenous use only; accidental intrathecal administration is fatal.
- These drugs are irritants and can cause significant local injury if extravasation occurs.
Mechanism of Action
Plant alkaloids interfere with cell division by disrupting chromosome alignment and microtubule-dependent mitotic processes. This prevents normal mitosis and leads to apoptosis in rapidly dividing malignant cells.
Common Drugs
- Vincristine
- Vinblastine
- Etoposide
Nursing Considerations
- Assess baseline and ongoing neurologic status (sensory change, weakness, gait instability, new neuropathic pain).
- Monitor bowel pattern closely and escalate severe constipation or abdominal distention to prevent paralytic ileus progression.
- Monitor CBC trends and infection/bleeding indicators during treatment cycles.
- Verify IV patency throughout infusion and follow extravasation protocol immediately for local pain or swelling.
- Use route-safety controls for vincristine: IV infusion only, never intrathecal administration, and strict labeling/verification workflow.
- Review key interactions (for example CYP-modifying agents and selected anticoagulants) before each cycle.
Adverse Effects and Contraindications
- Neurologic: peripheral neuropathy, hearing change, autonomic dysfunction.
- GI: severe constipation, paralytic ileus, nausea/vomiting, mucositis.
- Hematologic: myelosuppression.
- Other: alopecia, urinary retention.
- Contraindications include hypersensitivity and selected neuropathy disorders such as Charcot-Marie-Tooth disease.
Health Teaching
- Report fever, chills, productive cough, dysuria, hematuria, and mouth sores promptly.
- Report numbness/tingling, new weakness, hearing change, and worsening constipation early.
- Maintain hydration and follow bowel-regimen instructions when prescribed.
- Avoid live vaccines and avoid new supplements or medications without oncology review.
- Use effective contraception during treatment.
Related Concepts
- high-alert-medications - Vincristine route errors are high-harm, never-event events.
- infiltration-and-extravasation - Irritant injury response during infusion therapy.
- leukopenia-and-neutropenia - Infection-risk monitoring during myelosuppression.
- thrombocytopenia-bleeding-risk-and-management - Bleeding-risk support during cytopenic phases.
Self-Check
- Why is vincristine route verification a critical safety step before administration?
- Which findings suggest progression from constipation to paralytic ileus?
- Which neurologic assessments should be trended during plant-alkaloid therapy?