Palonosetron Morningside Healthcare (Palonosetron)

Palonosetron is a selective 5‑HT3 receptor antagonist indicated for several nausea and vomiting pathways.

• Chemotherapy‑induced nausea and vomiting (CINV): Provides long‑lasting protection against acute and delayed phases.
• Post‑operative nausea and vomiting (PONV): Reduces the incidence of nausea and vomiting after surgery.
• Radiotherapy‑induced nausea and vomiting: Helps control nausea associated with radiation treatment.
• Anticipatory nausea and vomiting: Prevents nausea that occurs before chemotherapy in patients with prior experience.
• Nausea related to other emetogenic triggers : Offers broader anti‑emetic coverage in clinical practice.

• Palonosetron binds with high affinity to the 5‑HT3 receptors located on vagal afferent nerves in the gastrointestinal tract and the chemoreceptor trigger zone of the brain. By blocking these serotonin receptors, it inhibits the signaling cascade that initiates the vomiting reflex, providing prolonged anti‑emetic activity compared with first‑generation agents.

Palonosetron is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Headache: mild to moderate intensity.
• Constipation: transient gastrointestinal slowing.
• Fatigue: occasional tiredness.
• Dizziness: brief episodes of light‑headedness.
• Injection site erythema: mild redness at the IV site.

Serious or Rare Side Effects

• Allergic reaction: rash, pruritus, or anaphylaxis.
• Cardiac arrhythmia: QT‑interval prolongation.
• Severe constipation or intestinal obstruction.
• Serotonin syndrome: rare when combined with other serotonergic agents.
• Hypotension: notable drop in blood pressure post‑administration.

When using Palonosetron, clinicians should consider several safety aspects.

• Assess cardiac history: patients with known QT prolongation require ECG monitoring.
• Review concomitant serotonergic drugs: avoid additive serotonin effects.
• Evaluate renal and hepatic function: dose adjustment may be needed in severe impairment.
• Monitor for allergic reactions: watch for signs of rash or anaphylaxis during infusion.
• Store at ambient temperature: keep in the original packaging, protect from moisture and light.

Palonosetron may interact with other medications that influence serotonin pathways or cardiac conduction.

Major Interactions (Avoid)

• Other 5‑HT3 antagonists: concurrent use can increase toxicity risk.
• QT‑prolonging agents (e.g., quinidine, sotalol): may exacerbate cardiac rhythm disturbances.

Moderate Interactions (Monitor Closely)

• Serotonergic antidepressants (SSRIs, SNRIs, MAOIs): potential for serotonin syndrome.
• Antifungal azoles (ketoconazole, itraconazole): may affect drug metabolism.
• CYP3A4 inhibitors/inducers: monitor plasma levels for altered exposure.