Onseron 25Ml Syrup 4Mg/5Ml

Requires Prescription: Yes

Generics: Ondansetron

Used For: Nausea & Vomiting

How It Works:

Ondansetron is a selective antagonist of the 5-HT3 serotonin receptor subtype. While its exact mechanism in controlling chemotherapy-induced nausea and vomiting is not fully understood, it is believed to work by blocking serotonin receptors that trigger the vomiting reflex. Serotonin release from the small intestine, stimulated by chemotherapy or radiotherapy, activates 5-HT3 receptors on vagal afferents, initiating nausea and vomiting. Ondansetron may prevent this reflex by antagonizing these receptors. Additionally, it may affect serotonin release in the central nervous system, though its role in postoperative nausea and vomiting is not well-defined.

Dosage: Follow specific dosing instructions for ondansetron.

Side Effects:

Chemotherapy-Induced Nausea and Vomiting: Diarrhea, headache, fever, constipation, rash. Rarely: angina, ECG changes, hypotension, tachycardia, QT prolongation, ST segment depression, bradycardia, transient liver enzyme elevations, neurological effects such as seizures or extrapyramidal reactions, and hypokalemia.

Postoperative Nausea and Vomiting: Headache, drowsiness/sedation, injection site reactions, fever, cold sensation, pruritus, paresthesia. Rarely: pain, redness, burning at the injection site, hiccups, urticaria, Stevens-Johnson syndrome, toxic epidermal necrolysis, transient blindness, oculogyric crisis, and dizziness.

Drug Interactions:

Cytochrome P-450 Enzyme Modifiers: Apomorphine, phenytoin, carbamazepine, rifampin.

Serotonergic Drugs: Tramadol.

Chemotherapy Agents: Carmustine, etoposide, cisplatin.

Others: Temazepam, alfentanil, atracurium.

Indication:

Prevention of nausea and vomiting associated with initial and repeat courses of emetogenic cancer chemotherapy.

When Not to Use:

Ondansetron is contraindicated in patients with known hypersensitivity to the drug or any of its components. The concurrent use of ondansetron with apomorphine is also contraindicated due to the risk of profound hypotension and loss of consciousness.

Precautions:

Hypersensitivity reactions, including anaphylaxis and bronchospasm, have been reported in patients with a sensitivity to other 5-HT3 receptor antagonists.

Warnings:

Ondansetron can prolong the QT interval in a dose-dependent manner. It should be avoided in patients with congenital long QT syndrome. ECG monitoring is recommended for patients with electrolyte imbalances (e.g., hypokalemia, hypomagnesemia), heart failure, bradyarrhythmias, or those on other QT-prolonging medications.

Ondansetron may mask symptoms of progressive ileus and gastric distention in patients undergoing abdominal surgery or those with chemotherapy-induced nausea and vomiting.

Ondansetron does not stimulate gastric or intestinal peristalsis and should not replace nasogastric suction.

Additional Information:

Pregnancy Category: Consult your physician before using any medication during pregnancy.

Storage: Store at room temperature, away from direct light and heat.