Palonossetrom Pharmamatch (Palonosetron)

Palonosetron is a selective 5‑HT3 receptor antagonist used in the management of nausea and vomiting associated with chemotherapy and surgery.

• Chemotherapy‑induced nausea and vomiting (CINV): provides prophylaxis and acute control of emesis.
• Post‑operative nausea and vomiting (PONV): reduces incidence of nausea after general anesthesia.
• Radiotherapy‑induced nausea: helps control nausea associated with certain radiation treatments.
• Anticipatory nausea: used in patients with a history of severe CINV to prevent anticipatory episodes.
• Adjunct therapy in highly emetogenic regimens: enhances overall anti‑emetic coverage when combined with other agents.

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

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

Common Side Effects

• Headache: mild to moderate intensity.
• Constipation: reduced bowel movements.
• Fatigue: feeling of tiredness.
• Dizziness: transient light‑headedness.
• Injection site erythema: mild redness at the administration site.

Serious or Rare Side Effects

• Hypersensitivity reactions: rash, itching, swelling, or anaphylaxis.
• QT interval prolongation: potential cardiac rhythm changes.
• Severe constipation or intestinal obstruction.
• Serotonin syndrome: rare when combined with other serotonergic drugs.
• Neurotoxicity: uncommon neurological symptoms such as tremor.

Palonosetron should be used with consideration of patient‑specific factors and safety guidelines.

• Pregnancy: avoid unless clearly needed; limited data available.
• Breastfeeding: monitor infant; drug may be present in milk.
• Cardiac risk: assess QT interval in patients with known cardiac disease.
• Drug interactions: review concomitant serotonergic agents.
• Renal/hepatic impairment: adjust if severe organ dysfunction is present.
• Store at below 25°C: keep in original packaging, protect from moisture and light.

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

Major Interactions (Avoid)

• Other 5‑HT3 antagonists: additive anti‑emetic effect may increase risk of QT prolongation.
• Drugs that prolong QT interval: combined use can exacerbate cardiac rhythm disturbances.

Moderate Interactions (Monitor Closely)

• Serotonergic agents (e.g., SSRIs, SNRIs, tramadol): monitor for serotonin syndrome.
• CYP3A4 inhibitors/inducers: may alter palonosetron plasma levels.
• Anticholinergic drugs: may enhance constipation risk.
• Diuretics: monitor electrolyte balance, especially potassium.
• Anticoagulants: observe for any unexpected bleeding patterns.