Ondansetron is a serotonin 5-HT3 receptor antagonist which is used in controlling nausea and vomiting due to cancer chemotherapy, radiation therapy and surgery.
- Nausea during chemotherapy and radiation therapy
- Vomiting during chemotherapy and radiation therapy
- PONV (Post Operative nausea and vomiting)
0.15 mg/kg up to a maximum of 16 mg per dose
When patient is undergoing chemotherapy, the body in response to chemotherapeutic agent stimulates vagal afferents through serotonin receptors to initiate vomiting reflexes.
The 5HT3 receptor antagonist suppresses vomiting and nausea by serotonin binding to 5HT3 receptors.
These antagonize the action of serotonin and relieves in nausea and vomiting.
The mean peak plasma concentration at 10 minutes was 42.9ng/ml after I.V infusion and after 10 minutes it is 31.9ng/ml after IM route.
The plasma protein binding was 70-76% at pharmacological concentration range of 10 to 500ng/ml.
Drug also penetrates to erythrocytes during circulation.
In body ondansetron is metabolized by hydroxylation on indole ring and further to subsequent glucuronide or sulphate conjugation.
The elimination half life was 4hrs and difference on frequent dosing. A reduction in clearance is observed with the patient of 75 years of age.
- Hypersensitive patient
- Anaphylactic reaction are observed in patient
- Not to be co-administrated with apomorphine because of hypotension and loss of function.
- Patient with hypersensitivity reaction including anaphylaxis and bronchospasm were observed in other selective 5HT3 receptor antagonist.
- Prescription of Ondansetron should be avoided in patients with congenital long QT syndrome
- It should not be used instead of nasogastric suction.