Zofran/ Ondansetron

Question 1

Zofran Class

Answer 1

• Anti-emetic

* Selective Serotonin (5HT3) Receptor Antagonist

Question 2

Zofran Action

Answer 2

• Reduces vagus nerve activity (which activates the vomiting center).
• Blocks serotonin.
• Has little effect on vomiting caused by motion sickness.

Question 3

Zofran Indications

Answer 3

Moderate to severe N/v.

Question 4

Zofran Contraindications

Answer 4

• Hypersensitivity to the drug.
• Prolonged QT syndrome
• Concurrent use of Apomorphine (Apokyn), an anti-parkasonian drug.

Question 5

Zofran Precautions

Answer 5

• Not well studied in children less than 2 years of age
• Use with caution with patients concurrently using drugs which effect QT interval (i.e. Procainamide, Amiodarone, TCA’s, Haldol)
• Use with caution with hepatic impairment (consider prolonging dosage intervals or decreasing dose)

Question 6

Zofran Dosage

Answer 6

Adults:
• IV/IO/IM- 4 mg, repeated once in 15 min PRN
• ODT: 8 mg PO once.
Pediatrics: (>2 years of age)
• IV/IO/IM- 0.1 mg/kg IV/IO, MAX of 4 mg/Dose.
• Contact medical control to repeat.
• ODT: 8-15 kg: 2 mg PO once.
15-30 kg: 4 mg PO once.
>30 kg: 8 mg PO once.

Question 7

Zofran Onset/ Duration

Answer 7

Duration: 2-4 hours

Question 8

Zofran Side Effects

Answer 8

• Sedation
• Hypotension
• Tachycardia
• Angina
• EPS (Rare)
• Torsades de Pointes (rare)
• Constipation

Question 9

Zofran Interactions

Answer 9

• Additive effects with medications that prolong Q-T interval.
• Additive CNS depressant effects