Ondansetron Oral Liquid 2 mg/5 mL (P)
Description
Ondansetron Oral Liquid 2 mg/5 mL, often marked with ‘(P)’ to indicate its suitability for pediatric use, is a clear to yellowish, sweet-tasting oral solution. It contains Ondansetron Hydrochloride, a highly effective antiemetic (medication to prevent and treat nausea and vomiting). This concentration provides 2 milligrams of ondansetron in every 5 milliliters of liquid. As a selective 5-HT3 receptor antagonist, it works by blocking serotonin’s action on specific receptors in the brain and gut, thereby preventing nausea and vomiting caused by certain medical treatments or conditions. The liquid form is particularly advantageous for precise dosing in children and for patients who have difficulty swallowing tablets.
Advantages
- Precise Dosing: The liquid formulation allows for accurate and flexible dose adjustments, which is crucial for pediatric patients where dosing is often weight-based.
- Easy Administration: Ideal for children, infants (from 1 month of age for PONV, 6 months for CINV, under medical supervision), elderly patients, or individuals who struggle to swallow pills.
- Effective Antiemetic: Potently prevents and treats various types of nausea and vomiting, especially those linked to chemotherapy, radiation, and surgery.
- Targeted Action: By specifically blocking serotonin 5-HT3 receptors, it provides focused antiemetic effects with a generally favorable side effect profile compared to older, broader-acting antiemetics.
- Non-Sedating: At therapeutic doses, it typically does not cause significant drowsiness, which is beneficial for patient comfort and alertness.
Uses
Ondansetron Oral Liquid 2 mg/5 mL is commonly used for:
- Prevention of Chemotherapy-Induced Nausea and Vomiting (CINV): Used to prevent nausea and vomiting in children (from 6 months of age) and adults receiving chemotherapy.
- Prevention of Radiotherapy-Induced Nausea and Vomiting (RINV): To prevent or reduce nausea and vomiting caused by radiation therapy.
- Prevention and Treatment of Post-Operative Nausea and Vomiting (PONV): Used to prevent and treat nausea and vomiting following surgical procedures in children (from 1 month of age) and adults.
- Acute Gastroenteritis (Off-label/Cautioned Use in Children): Sometimes used as a single oral dose for severe gastroenteritis in children to reduce vomiting and the need for intravenous rehydration, but routine prophylaxis is generally not recommended, and careful monitoring for dehydration and masking of underlying issues is necessary.
Nature
Ondansetron is a selective serotonin 5-HT3 receptor antagonist. Its antiemetic effects stem from its ability to block the action of serotonin, a key neurotransmitter involved in triggering the vomiting reflex.
The mechanism of action involves:
- Blocking Receptors in the Chemoreceptor Trigger Zone (CTZ): Ondansetron blocks 5-HT3 receptors located in the chemoreceptor trigger zone (CTZ) in the brain. The CTZ detects circulating emetic stimuli (like those released during chemotherapy) and signals the vomiting center.
- Blocking Receptors on Vagal Nerve Terminals in the Gut: Chemotherapy and radiation can cause damage to cells in the gut (enterochromaffin cells), leading to the release of serotonin. This serotonin then activates 5-HT3 receptors on vagal afferent nerve fibers that transmit signals from the gut to the brain’s vomiting center. Ondansetron blocks these peripheral receptors, interrupting this signal pathway.
By acting at both central (CTZ) and peripheral (gut) sites, Ondansetron effectively prevents and treats nausea and vomiting by interrupting the serotonin-mediated pathways that lead to the emetic response.
Storage
- Room Temperature: Store Ondansetron Oral Liquid 2 mg/5 mL at controlled room temperature, typically between 20∘C to 25∘C (68∘F to 77∘F). Some manufacturers may allow storage up to 30∘C.
- Protect from Light: Keep the bottle in its original packaging or a dark place to protect it from light, which can cause degradation.
- Protect from Freezing: Do not freeze the liquid, as this can alter its consistency and effectiveness.
- Keep Out of Reach of Children: Store the medication in a secure place, well out of the sight and reach of children and pets. Always use the provided measuring device (syringe or spoon) to ensure accurate dosing and prevent accidental overdose.
- Check Expiry Date: Always check the expiry date printed on the packaging. Do not use the medication after this date. Properly dispose of any expired or unused medication according to local guidelines.