Informational only — Not medical advice. Always consult a licensed healthcare provider.

Community data Updated 2 months ago

Indications

Vomisal is a serotonin subtype 3 (5-HT3) receptor antagonist. It is used to prevent nausea and vomiting caused by emetogenic cancer chemotherapy, whether given as an initial or repeat course, to prevent and treat nausea and vomiting occurring after surgery, and to prevent nausea and vomiting caused by radiotherapy.

⚠️ Always consult a registered physician before taking any medicine.

Pharmacology

Ondansetron is a potent, highly selective 5HT3 receptor antagonist. Its precise mode of action in controlling nausea and vomiting is not known. Chemotherapy drugs and radiotherapy can trigger the release of 5HT in the small intestine, which starts a vomiting reflex by activating vagal afferents through 5HT3 receptors; ondansetron blocks this reflex from starting. Activation of vagal afferents may also release 5HT in the area postrema, a region on the floor of the fourth ventricle, which can further promote vomiting through a central mechanism. Ondansetron's effect in managing nausea and vomiting caused by cytotoxic chemotherapy and radiotherapy is therefore thought to result from its blocking of 5HT3 receptors on neurons in both the peripheral and central nervous systems. How it works in post operative nausea and vomiting is not known, though it may share common pathways with chemotherapy induced nausea and vomiting.

Pregnancy & Breastfeeding

Ondansetron did not cause cancer in 2-year studies in rats and mice, using oral doses as high as 10 and 30 mg/kg per day respectively, and it showed no mutagenic effect in standard genetic toxicity tests. Oral doses up to 15 mg/kg per day did not affect fertility or overall reproductive performance in male and female rats.

Reproduction studies in pregnant rats and rabbits, using daily oral doses of up to 15 and 30 mg/kg per day respectively, found no evidence that Ondansetron impaired fertility or harmed the developing fetus. However, no adequate, well-controlled studies have been conducted in pregnant women. Ondansetron does pass into the breast milk of rats, so it should be used with caution in nursing mothers.

⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.

Dosage Reference

⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.

Adults: Dosage Chemotherapy-Induced Nausea and Vomiting-Adults, Pediatric patients (6 months to 18 years): 8 mg tablet/orodispersible tablet: Three 0.15 mg/kg doses, up to a maximum of 16 mg per dose. 4 mg orodispersible tablet: Three 0.15 mg/kg doses, up to a maximum of 16 mg per dose. Injection: Three 0.15 mg/kg doses, up to a maximum of 16 mg per dose, infused intravenously over 15 minutes. Radiotherapy-Induced Nausea and Vomiting-Adults: 8 mg tablet/orodispersible tablet: Initial Dose: 8 mg orally 1 to 2 hours before radiotherapy. Post Radiotherapy: 8 mg orally every 8 hours for up to 5 days after a course of treatment. 4 mg orodispersible tablet: Three 0.15 mg/kg doses, up to a maximum of 16 mg per dose. Injection: Three 0.15 mg/kg doses, up to a maximum of 16 mg per dose, infused intravenously over 15 minutes. Postoperative Nausea and Vomiting-Adults: 8 mg tablet/orodispersible tablet: 16 mg given as two 8 mg tablets 4 mg orodispersible tablet: 16 mg Injection: 4 mg Pediatrics (>40 kg): Injection: 4 mgPediatrics (40 kg): Injection: 0.1 mg/kgChemotherapy-induced Nausea and Vomiting-Adults/Geriatric/Child of 12 years or over: Highly emetogenic cancer chemotherapy: 30 ml (24 mg) Ondansetron Oral Solution administered 30 minutes before start of emetogenic chemotherapy. Moderate emetogenic cancer chemotherapy: 10 ml (8 mg) Ondansetron Oral Solution administered 30 minutes before start of emetogenic chemotherapy. A further 10 ml dose should be administered after 8 hours of the first dose. One 10 ml dose should be administered twice a day (every 12 hours) for 1-2 days after completion of chemotherapy. Pediatric (4-11 years): 5 ml (4 mg) Ondansetron Oral Solution should be taken 30 minutes before the start of chemotherapy. The other 2 doses should be taken 4 and 8 hours after the first dose. Then 5 ml oral solution should be administered 3 times a day (every 8 hours) for 1-2 days after completion of chemotherapy. Oral solution: Radiotherapy induced Nausea and Vomiting (Adults/Geriatric/Child of 12 years or over): The recommended oral dosage: 10 ml (8 mg) Ondansetron Oral Solution 3 times daily. For total body irradiation: 10 ml (8-mg) Ondansetron Oral Solution should be administered 1 to 2 hours before each fraction of radiotherapy administered each day. For single high-dose fraction radiotherapy to the abdomen: one 10 ml Ondansetron Oral Solution should be administered 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose for 1 to 2 days after completion of radiotherapy. For daily fractionated radiotherapy to the abdomen: 10 ml (8-mg) Ondansetron Oral Solution should be administered 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose for each day radiotherapy is given. Postoperative Nausea and Vomiting (Adults/Geriatric/Child of 12 years or over): 20 ml (16 mg) Ondansetron Oral Solution 1 hour before induction of anesthesia Oral Soluble Film: Prevention of nausea and vomiting associated with highly emetogenic cancer chemotherapy: Adult oral dose: 24 mg given successively as three 8 mg films 30 minutes before the start of chemotherapy. Prevention of nausea and vomiting associated with moderately emetogenic cancer chemotherapy: Adults and pediatric patients 12 years of age and older: One 8 mg film 30 minutes before chemotherapy followed by an 8 mg dose 8 hours later. Administer one 8 mg film twice a day (every 12 hours) for 1 to 2 days after completion of chemotherapy. Pediatric patients 4 through 11 years of age: One 4 mg film three times a day. Administer the first dose 30 minutes before chemotherapy, with subsequent doses 4 and 8 hours later. Administer one 4 mg film three times a day (every 8 hours) for 1 to 2 days after completion of chemotherapy. Prevention of nausea and vomiting associated with radiotherapy: The adult dosage is one 8 mg film three times a day. Postoperative nausea and vomiting: The adult dose is 16 mg given successively as two 8 mg films 1 hour before anesthesia.

Side Effects & Interactions

Side Effects

No side-effect data recorded yet.