Zofran (Ondasetron)

Zofran (Ondasetron)

drug name:	zofranx
image:	zofran.png
caption:	zofran 4 mg tablet
type:	antiemetic
routes of administration:	oral, intravenous, intramuscular
metabolism:	liver (CYP2D6, CYP3A4)
legal status:	prescription only
bioavailability:	sss
protein bound:	70-76%
elimination half-life:	3-6 hours
excretion:	kidney (60%), feces (40%)

Zofran (ondansetron) is an antiemetic medication used to prevent nausea and vomiting, particularly in the field of anesthesia. It is a selective 5-HT3 receptor antagonist, which works by blocking the action of serotonin in the brain and the gastrointestinal tract.

Route of administration

• Oral: Disintegrating tablets, film-coated tablets, and oral solution
• Intravenous: Injection
• Intramuscular: Injection

Dose

For anesthesia-related nausea and vomiting:

• Adult:

 * Oral: 16 mg before anesthesia induction
 * Intravenous: 4 mg before anesthesia induction or immediately before/during/after surgery

• Pediatric:

 * Oral: 4 mg for children aged 4-11 years, 30-60 minutes before surgery
 * Intravenous: 0.1 mg/kg (up to 4 mg) for children aged 1 month-12 years, immediately before/during/after surgery

Half-life

• The elimination half-life of ondansetron is approximately 3-6 hours.

Expected time to work

• Oral: Onset of action is approximately 30 minutes to 2 hours.
• Intravenous: Onset of action is approximately 5-30 minutes.

Use in anesthesia

Zofran is commonly used in anesthesia to:

• Prevent postoperative nausea and vomiting (PONV)
• Prevent nausea and vomiting induced by chemotherapy
• Prevent nausea and vomiting associated with radiation therapy

Side effects

• Headache
• Fatigue
• Constipation
• Diarrhea
• Dizziness

Contraindications

• Hypersensitivity to ondansetron or any component of the formulation
• Concomitant use with apomorphine
• Patients with congenital long QT syndrome

Drug interactions

• Serotonin syndrome risk may increase when combined with other serotonergic agents (e.g., SSRIs, SNRIs, TCAs, MAOIs, triptans)

External links

• Template:DrugBank
• Template:RxList
• Template:MedlinePlus