Ondansetron

Question 1

Generic name for Zofran

Answer 1

Ondansetron

Question 2

Trade name for Ondansetron

Answer 2

Zofran

Question 3

Classification of Ondansetron

Answer 3

Serotonin Receptor Antagonist, and Antiemetic

Question 4

MOA (Pharmacodynamics) of Ondansetron

Answer 4

Zofran is a selective serotonin 5-HT3 receptor antagonist. It blocks serotonin binding to these receptors both peripherally on vagal nerve terminals and centrally in the CTZ. This prevents serotonin from being able to stimulate nausea and vomiting.

Question 5

Indications for Ondansetron Admin

Answer 5

1. Preventions of N/V (i.e., head injury, spinal injury, AAA, open eye injury)
2. Prevention of NV associated with initial and repeat courses of emetogenic cancer chemotherapy, including high dose cisplatin
3. Prevention of N/V associated with radiation therapy
4. Prevention of post operative N/V
5. Prophylaxis and treatment of N/V

Question 6

Adult: Dosages for Ondansetron

Answer 6

Adult:
4 to 8 mg SIVP over 2-5 min q 8 hours
8 mg IM q 8 hours
4 mg SL q 8 hours

Question 7

Contraindications for Ondansetron

Answer 7

Hypersensitivity to the drug

Question 8

Precautions when administering Ondansetron

Answer 8

• Caution with admin to patients at risk of QT interval prolongation >500 QTC, cardiac arrhythmias, or patients over the age of 65; In these patients dilute ondansetron in 50 ml and infuse over 15 minutes. The usual dose problems can occur is at 16mg.
• Ondansetron is not effective in preventing motion-induced nausea and vomiting.
• Patients with hepatic failure

Question 9

Pediatric: Doses for Ondansetron

Answer 9

<4 yrs old with a weight >8 kg = 2 mg PO
>4 years old = 4 mg PO

0.1 mg/kg SIVP/IO to max 4 mg