Palonosetron Reig Jofre Uk (Palonosetron)

Palonosetron is a selective 5‑HT3 receptor antagonist indicated for the prevention of chemotherapy‑induced and postoperative nausea and vomiting.

• Chemotherapy‑induced nausea and vomiting (CINV): helps reduce the incidence of acute and delayed vomiting after highly emetogenic chemotherapy.
• Moderate emetogenic chemotherapy (MEC)‑induced nausea and vomiting: provides effective prophylaxis for patients receiving moderate risk regimens.
• Post‑operative nausea and vomiting (PONV): reduces the frequency of nausea and vomiting following general anesthesia.
• Radiotherapy‑induced nausea and vomiting: used as part of anti‑emetic regimens for patients undergoing radiation therapy that may trigger emesis.

• Palonosetron binds with high affinity to the serotonin 5‑HT3 receptors located on vagal afferent nerves in the gastrointestinal tract and the chemoreceptor trigger zone. By blocking these receptors, it prevents serotonin‑mediated activation of the vomiting centre, thereby inhibiting both acute and delayed phases of nausea and vomiting associated with chemotherapy or surgery.

Palonosetron may cause a range of adverse reactions, most of which are mild to moderate in intensity.

Common Side Effects

• Headache: mild to moderate headache reported in clinical studies.
• Constipation: transient reduction in bowel movements.
• Fatigue: general feeling of tiredness.
• Dizziness: occasional light‑headed sensation.
• Injection site reactions: mild erythema or discomfort at the site of administration.

Serious or Rare Side Effects

• QT interval prolongation: may affect cardiac repolarisation, requiring ECG monitoring in susceptible patients.
• Severe hypersensitivity: anaphylactic reactions including rash, swelling, or respiratory distress.
• Serotonin syndrome: rare but possible when combined with other serotonergic agents.
• Cardiac arrhythmias: uncommon ventricular arrhythmias in high‑risk individuals.
• Severe constipation or intestinal obstruction: rare gastrointestinal complications requiring medical attention.

When using Palonosetron, clinicians should consider several safety aspects to minimise risk.

• Cardiac monitoring: assess baseline ECG in patients with known QT prolongation or electrolyte disturbances.
• Concomitant serotonergic drugs: evaluate risk of serotonin syndrome when used with other serotonergic agents.
• Electrolyte balance: correct hypokalaemia, hypomagnesaemia or hypocalcaemia before administration.
• Pregnancy and lactation: use only if the potential benefit outweighs the risk; data are limited.
• Renal or hepatic impairment: dose adjustment may be required; monitor organ function.
• Store at ambient temperature: keep below 25°C, protect from moisture and light, and retain in original packaging.

Palonosetron has a low potential for drug‑drug interactions, but certain combinations warrant caution.

Major Interactions (Avoid)

• Other QT‑prolonging agents: concurrent use may increase risk of cardiac arrhythmias.
• Strong CYP3A4 inhibitors/inducers: may alter plasma levels of palonosetron, though clinical relevance is limited.

Moderate Interactions (Monitor Closely)

• Serotonergic medications (e.g., SSRIs, tramadol): monitor for signs of serotonin syndrome.
• Anticholinergic drugs: may exacerbate constipation.
• Diuretics causing electrolyte loss: watch for increased QT prolongation risk.
• Antifungal azoles: potential additive effect on QT interval.
• Anesthetic agents: observe for enhanced hypotensive responses.