Navelbine (Vinorelbine Tartrate)

Vinorelbine is a Vinca alkaloid antineoplastic agent used in the management of solid tumours.

• Non‑small cell lung cancer: used as first‑line or second‑line therapy to reduce tumor burden and improve progression‑free survival.
• Metastatic breast cancer: administered to control disease spread and alleviate symptoms in patients with prior chemotherapy.
• Combination chemotherapy for solid tumours: incorporated with agents such as cisplatin or gemcitabine to enhance overall cytotoxic response.
• Advanced NSCLC in combination regimens: contributes to response rates when given with other antineoplastic drugs.

• Vinorelbine binds to tubulin at the vinca binding site, preventing the addition of α‑ and β‑tubulin dimers and thereby inhibiting microtubule polymerisation. This disruption blocks formation of the mitotic spindle, arresting cells in the M‑phase of the cell cycle and leading to apoptotic cell death in rapidly dividing cancer cells. The drug’s affinity for tubulin is higher in proliferating cells, providing selective toxicity toward malignant tissue while sparing most normal cells.

Vinorelbine may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Neutropenia: reduced neutrophil count leading to increased infection risk.
• Nausea: feeling of sickness often accompanied by an urge to vomit.
• Vomiting: expulsion of stomach contents, may be acute or delayed.
• Constipation: difficulty passing stools, sometimes requiring laxatives.

Serious or Rare Side Effects

• Febrile neutropenia: fever with low neutrophil count, requiring urgent medical attention.
• Severe infection: opportunistic infections due to immunosuppression.
• Pulmonary toxicity: inflammation or fibrosis of lung tissue that can impair breathing.

When prescribing vinorelbine, several safety considerations should be observed to minimise risk.

• Blood count monitoring: perform complete blood counts regularly to detect neutropenia.
• Liver function assessment: evaluate hepatic enzymes before and during therapy.
• Pulmonary evaluation: screen for existing lung disease prior to initiation.
• Bone marrow suppression: avoid in patients with severe marrow compromise.
• Store at ambient temperature: keep in original packaging, protect from moisture and light.

Vinorelbine can interact with other medicines, affecting its efficacy or safety.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): increase vinorelbine plasma levels.
• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): reduce drug exposure.
• Concurrent myelosuppressive agents (e.g., cyclophosphamide, doxorubicin): heighten risk of severe bone‑marrow toxicity.
• Other Vinca alkaloids (e.g., vincristine, vinblastine): additive neurotoxicity.
• Monoclonal antibodies affecting bone marrow (e.g., bevacizumab): may exacerbate hematologic effects.

Moderate Interactions (Monitor Closely)

• CYP2D6 inhibitors (e.g., fluoxetine): may modestly raise vinorelbine concentrations.
• NSAIDs (e.g., ibuprofen): can increase risk of gastrointestinal toxicity.