Palonozetron Kalceks (Palonosetron)

Palonosetron is indicated for prevention of nausea and vomiting associated with chemotherapy and surgery.

• Chemotherapy‑induced nausea and vomiting (CINV): Reduces the incidence and severity of acute and delayed CINV.
• Post‑operative nausea and vomiting (PONV): Decreases the frequency of nausea and vomiting after surgical procedures.
• Radiotherapy‑induced nausea and vomiting: Helps control symptoms when radiation therapy triggers emesis.
• Antiemetic prophylaxis in highly emetogenic regimens: Provides extended protection for patients receiving highly emetogenic chemotherapy protocols.

• Palonosetron selectively binds to the 5‑HT₃ receptors in the central nervous system and gastrointestinal tract, blocking serotonin‑mediated signaling that triggers the vomiting reflex. Its high affinity and prolonged receptor occupancy result in sustained anti‑emetic activity that lasts beyond the plasma half‑life, covering both acute and delayed phases of chemotherapy‑induced nausea and vomiting.

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

Common Side Effects

• Headache: Mild to moderate headache reported in clinical studies.
• Constipation: Reduced bowel motility leading to occasional constipation.
• Fatigue: General feeling of tiredness or lack of energy.
• Dizziness: Transient episodes of light‑headedness.

Serious or Rare Side Effects

• QT interval prolongation: May affect cardiac electrical activity, requiring ECG monitoring in susceptible patients.
• Severe hypersensitivity: Includes rash, pruritus, bronchospasm, or anaphylaxis.
• Serotonin syndrome: Rare but possible when combined with other serotonergic agents.
• Cardiac arrhythmias: Uncommon arrhythmic events reported in post‑marketing surveillance.

When using Palonosetron, consider the following safety measures:

• Cardiac monitoring: Assess baseline ECG in patients with known QT prolongation risk.
• Concomitant serotonergic drugs: Review all serotonergic medications to avoid additive effects.
• Electrolyte balance: Correct hypokalemia, hypomagnesemia, or hypocalcemia before administration.
• Pregnancy and lactation: Use only if the potential benefit justifies the risk.
• Renal or hepatic impairment: Adjust monitoring in patients with severe organ dysfunction.
• Store at ambient temperature: Keep below 25°C, protect from moisture and light.

Palonosetron may interact with several drug classes.

Major Interactions (Avoid)

• QT‑prolonging agents: Co‑administration can increase risk of cardiac arrhythmias.
• Potent CYP3A4 inhibitors: May raise palonosetron plasma levels, though clinical relevance is limited.

Moderate Interactions (Monitor Closely)

• Other serotonergic agents: May increase risk of serotonin syndrome.
• Anticholinergic drugs: May exacerbate constipation.
• Diuretics causing electrolyte loss: Heighten risk of QT prolongation.
• Anesthetic agents used in surgery: May compound hypotensive effects.