Palonosetron Fresenius Kabi (Palonosetron Hydrochloride)

Palonosetron is a 5‑HT3 receptor antagonist indicated for the prevention of nausea and vomiting in several clinical contexts.

• Chemotherapy‑induced nausea and vomiting (CINV): Provides long‑lasting protection against acute and delayed episodes following highly emetogenic chemotherapy.
• Post‑operative nausea and vomiting (PONV): Reduces the incidence of nausea and vomiting after general anesthesia.
• Radiotherapy‑induced nausea and vomiting: Helps control nausea associated with radiation treatment of the abdomen or pelvis.
• Anticipatory nausea and vomiting: Used in patients who have previously experienced CINV or PONV to prevent recurrence.
• Adjunct therapy in combination regimens: Integrated into multi‑drug anti‑emetic protocols for enhanced efficacy.

• Palonosetron binds with high affinity to the 5‑HT3 receptors located on vagal afferent nerves in the gastrointestinal tract and the chemoreceptor trigger zone. By blocking serotonin from activating these receptors, it interrupts the neural signaling cascade that initiates the vomiting reflex, providing prolonged anti‑emetic protection that can extend beyond 24 hours after a single dose.

Palonosetron is generally well tolerated, but adverse reactions have been reported.

Common Side Effects

• Headache: mild to moderate intensity.
• Constipation: transient gastrointestinal slowing.
• Fatigue: feeling of tiredness without other cause.
• Diarrhoea: occasional loose stools.
• Dizziness: brief episodes of light‑headedness.

Serious or Rare Side Effects

• QT interval prolongation: may predispose to cardiac arrhythmias.
• Severe hypersensitivity: rash, itching, swelling, or anaphylaxis.
• Serotonin syndrome: rare when combined with other serotonergic agents.
• Severe constipation or intestinal obstruction.
• Pulmonary edema: fluid accumulation in the lungs.
• Neuro‑muscular weakness: rare neuromuscular complications.

When using Palonosetron, clinicians should consider several safety aspects.

• Cardiac monitoring: assess baseline ECG in patients with known QT prolongation risk.
• Concomitant serotonergic drugs: evaluate for additive serotonin effects.
• Electrolyte disturbances: correct hypokalaemia, hypomagnesemia, or hypocalcaemia before administration.
• Renal or hepatic impairment: adjust monitoring in patients with severe organ dysfunction.
• Pregnancy and lactation: use only if the potential benefit outweighs risk.
• Store at ambient temperature: keep in original packaging, protect from light and moisture.

Palonosetron may interact with other medications, requiring attention to the level of risk.

Major Interactions (Avoid)

• Other 5‑HT3 antagonists: concurrent use can increase toxicity without added benefit.
• QT‑prolonging agents: combined use may heighten risk of cardiac arrhythmias.
• Strong CYP3A4 inhibitors: may raise palonosetron plasma concentrations.

Moderate Interactions (Monitor Closely)

• Serotonergic antidepressants (SSRIs, SNRIs): monitor for signs of serotonin syndrome.
• Anticholinergic drugs: may exacerbate constipation.
• Diuretics: watch for electrolyte shifts that could affect cardiac repolarisation.
• Antifungal azoles: potential modest increase in exposure.
• Opioid analgesics: observe for additive nausea risk.