Palonosetron

Oral
Prophylaxis of chemotherapy-induced nausea and vomiting
Adult: For cases associated with moderately emetogenic cancer chemotherapy: 500 mcg approx 1 hour prior to the start of chemotherapy.

Intravenous
Prophylaxis of chemotherapy-induced nausea and vomiting
Adult: For cases associated with moderately or highly emetogenic cancer chemotherapy: 250 mcg as a single dose via bolus inj over 30 seconds to be given approx 30 minutes before chemotherapy.
Child: ≥1 month to 17 years For cases associated with moderately or highly emetogenic cancer chemotherapy: 20 mcg/kg (Max: 1,500 mcg) as a single dose via infusion over 15 minutes to be given approx 30 minutes before chemotherapy.

Intravenous
Prophylaxis of postoperative nausea and vomiting
Adult: 75 mcg as a single dose administered over 10 seconds immediately prior to the induction of anaesthesia.

Patient with history of constipation, signs of subacute intestinal obstruction; known or susceptibility to QT prolongation (e.g. history of QT prolongation, electrolyte abnormalities, CHF, bradyarrhythmia, conduction disturbances, patients taking antiarrhythmics or agents that cause QT prolongation or electrolyte abnormalities). Children. Pregnancy and lactation. Patient Counselling This drug may cause dizziness, somnolence or fatigue; if affected, do not drive or operate machinery. Monitoring Parameters Correct hypokalaemia and hypomagnesaemia prior to administration. Evaluate allergy history for 5-HT₃ receptor antagonist before administration. Monitor for signs and symptoms of serotonin syndrome.

Significant: Hypersensitivity reaction, including anaphylaxis and anaphylactic shock; increased ECG intervals (dose-dependent) such as PR, QT/QTc, QRS duration, and JT intervals; reduced heart rate, increased large bowel transit time. Cardiac disorders: Tachycardia, sinus bradycardia. Eye disorders: Eye swelling (oral); eye irritation (IV). Gastrointestinal disorders: Constipation, diarrhoea, flatulence, abdominal pain. General disorders and administration site conditions: Asthenia, fatigue. Rarely, inj/infusion site reactions including pain, discomfort, burning sensation, and induration (IV). Investigations: Increased AST or ALT. Metabolism and nutrition disorders: Hyperkalaemia. Musculoskeletal and connective tissue disorders: Myalgia (oral); arthralgia (IV). Nervous system disorders: Headache, dizziness, somnolence. Psychiatric disorders: Anxiety, insomnia. Renal and urinary disorders: Urinary retention. Skin and subcutaneous tissue disorders: Pruritus, rash. Vascular disorders: Hypotension.
Potentially Fatal: Serotonin syndrome.

Palonosetron is a selective high-affinity 5-HT₃ receptor antagonist. It inhibits serotonin on vagal nerve terminals in the periphery and centrally in the chemoreceptor trigger zone.
Absorption: Well absorbed (oral). Absolute bioavailability: 97% (oral). Time to peak plasma concentration: 5.1 ± 5.9 hours (oral).
Distribution: Widely distributed in the body. Plasma protein binding: Approx 62%. Volume of distribution: 8.3 ± 2.5 L/kg.
Metabolism: Metabolised in the liver (approx 50%) mainly by CYP2D6 and to a lesser extent by CYP3A4 and CYP1A2 isoenzymes into N-oxide-palonosetron and 6-S-hydroxy-palonosetron (inactive metabolites).
Excretion: IV: Via urine (approx 80%; approx 40% as unchanged drug). Oral: Via urine (85-93%; approx 40% as unchanged drug); faeces (5-8%). Terminal elimination half-life: Approx 40 hours.

Intravenous: Store between 15-30°C. Do not freeze. Protect from light. Oral: Store between 15-30°C.

Antiemetics / Supportive Care Therapy

A04AA05 - palonosetron ; Belongs to the class of serotonin (5HT3) antagonists. Used for the prevention of nausea and vomiting.