Paloron 0.5mg

Paloron 0.5mg — Palonosetron Hydrochloride Tablet

Paloron 0.5mg (Palonosetron Hydrochloride) is a second-generation selective 5-HT3 receptor antagonist manufactured by Ziska Pharmaceuticals Ltd. — Bangladesh's trusted specialty pharmaceutical company. Unlike first-generation 5-HT3 antagonists (ondansetron, granisetron, dolasetron), Palonosetron demonstrates uniquely strong receptor binding affinity (~30× greater than ondansetron) and an exceptionally long plasma half-life of approximately 40 hours — enabling a single oral dose to prevent both acute and delayed chemotherapy-induced nausea and vomiting (CINV).

Indications (Uses)

• Acute CINV — prevention of nausea and vomiting within 24 hours of moderately or highly emetogenic chemotherapy
• Delayed CINV — prevention of nausea and vomiting occurring 24–120 hours after chemotherapy (unique advantage over older 5-HT3 antagonists)
• PONV prevention — postoperative nausea and vomiting (IV formulation; oral 0.5mg used in oncology settings)
• Used by fertility clinics to prevent nausea during ovarian stimulation and egg retrieval procedures (OHSS-related symptoms)

Mechanism of Action (Pharmacology)

Palonosetron selectively antagonises the 5-HT3 serotonin receptor — both peripherally on vagal nerve terminals in the gut (blocking the acute emetic trigger) and centrally in the chemoreceptor trigger zone of the medulla oblongata. Its allosteric binding mechanism enables prolonged receptor blockade beyond its plasma concentration, explaining its 40-hour effective duration from a single dose.

Additionally, Palonosetron inhibits substance P (NK1) signaling pathways, which contributes to its superior efficacy against delayed CINV compared to older 5-HT3 antagonists.

Dosage & Administration

• Oral (Tablet 0.5mg): One 0.5mg tablet approximately 1 hour before the start of chemotherapy — single dose
• No dose reduction needed for elderly patients or mild-to-moderate renal/hepatic impairment
• May be combined with dexamethasone for highly emetogenic chemotherapy regimens (e.g., cisplatin-based)
• Swallow whole with water; may be taken with or without food

Contraindications

• Known hypersensitivity to Palonosetron or any component of the formulation
• Use caution in patients with known QT prolongation or those taking other QT-prolonging medicines

Side Effects

Common: Headache, constipation.

Less common: Dizziness, fatigue, diarrhoea, abdominal pain.

Rare: QT interval prolongation (cardiac rhythm change — monitor in patients with pre-existing cardiac conditions), hypersensitivity reactions.

Drug Interactions

• Palonosetron is metabolised by CYP2D6 and CYP3A4 — strong inhibitors of these enzymes may increase plasma levels
• Avoid concurrent use with other QT-prolonging medicines (certain antibiotics, antifungals, antipsychotics)
• Serotonin syndrome risk when combined with other serotonergic agents (SSRIs, SNRIs, triptans) — use with caution

Storage

Store below 30°C in a cool, dry place. Protect from light and moisture. Keep out of reach of children.

Palonosetron vs. Ondansetron — Key Differences

• Half-life: Palonosetron ~40 hours vs. Ondansetron ~5 hours — one dose covers both acute and delayed CINV
• Receptor affinity: Palonosetron ~30× stronger binding to 5-HT3 receptors
• Delayed CINV: Palonosetron is the only oral 5-HT3 antagonist with proven efficacy against delayed CINV
• Dosing frequency: Palonosetron — once per chemo cycle; Ondansetron — multiple doses per day

Paloron is a prescription medicine. It should be used under the supervision of an oncologist or treating physician. This information is for educational purposes only.