Drug Index

Ondansetron

 
print

Mechanism :

Ondansetron is a selective 5-HT3 receptor antagonist. While its mechanism of action has not been fully characterized, ondansetron is not a dopamine-receptor antagonist. Serotonin receptors of the 5-HT3 type are present both peripherally on vagal nerve terminals and centrally in the chemoreceptor trigger zone of the area postrema. It is not certain whether ondansetron antiemetic action is mediated centrally, peripherally, or in both sites.


Indication :

• Chemotherapy induced nausea and vomiting

• Post-operative nausea and vomiting


Contraindications :

Contraindicated for patients known to have hypersensitivity to the drug.


Dosing :

Nausea and vomiting chemotherapy induced:

Oral:

4-12 years: 4 mg started half hour before chemotherapy, then 4 and 8 hours after first dose, then 3 times a day for 1-2 days after chemotherapy.

>12 years: 8 mg started half hour before chemotherapy, then 2 times a day for 1-2 days after chemotherapy or a single dose of 24 mg.

IV:

>6 months: 0.15 mg/kg over 15 mins, given half hour before chemotherapy, then 4 and 8 hours after first dose. Max: 16 mg per dose.

Post-op nausea and vomiting:

Give slow IV slow infusion.

1 month-12 years: 0.1 mg/kg in <40 kg and 4 mg in >40 kg.

12-18 years: 4 mg before anaesthesia or after procedure (IV/IM)

OR, 16 mg 1 hour before anesthesia orally.


Adverse Effect :

Commonly reported adverse reactions include headache, malaise, fatigue, constipation and diarrhea.


Interaction :

Phenytoin, Carbamazepine, and Rifampicin: The clearance of ondansetron was significantly increased, and ondansetron blood concentrations were decreased.



Renal Dose :

Dose in Renal Impairment GFR (mL/min)
20-50Dose as in normal renal function
10-20Dose as in normal renal function
<10Dose as in normal renal function

Dose in Patients undergoing Renal Replacement Therapies
CAPDUnlikely to be dialysed. Dose as in normal renal function
HDNot dialysed. Dose as in normal renal function
HDF/High fluxUnknown dialysability. Dose as in normal renal function
CAV/VVHDUnknown dialysability. Dose as in normal renal function

Hepatic Dose :

Per the manufacturer, ondansetron dosage should not exceed 8 mg/day IV or PO in adult patients with severe hepatic impairment. In such patients, plasma clearance is reduced, resulting in a dramatically prolonged elimination half-life. No specific pediatric recommendations are available.

Severe hepatic impairment
IV dosing on day 1: 0.075mg/kg/dose Maximum dose being 4mg for children 2-11y and 8 mg/dose in children greater than 12 years of age.
Oral dosing: for Infants and Children of ages 6 months to 10 years
8 to 15 kg: 1 mg/dose once
>15 to 30 kg: 2 mg/dose once
>30 kg: 4 mg/dose once
05/26/2020 05:04:06 Ondansetron
ask a doctor
Ask a Doctor
Disclaimer: The information given by www.pediatriconcall.com is provided by medical and paramedical & Health providers voluntarily for display & is meant only for informational purpose. The site does not guarantee the accuracy or authenticity of the information. Use of any information is solely at the user's own risk. The appearance of advertisement or product information in the various section in the website does not constitute an endorsement or approval by Pediatric Oncall of the quality or value of the said product or of claims made by its manufacturer.
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0