# Ondansetron

#### **GENERIC NAME**

#### Ondansetron

#### **TRADE NAME**

#### Zofran

#### **DESCRIPTION**

Ondansetron (Zofran) is primarily used to treat nausea and vomiting. It is a serotonin receptor antagonist that effectively blocks the vomiting reflex. The duration of action is approximately 8 hours.

#### **HOW SUPPLIED**

- Ampule: 4 mg / 2 ml
- Orally Disintegrating Tablet (ODT): 4 mg tablet (scored)

#### **INDICATIONS**

- Nausea
- Vomiting

#### **CONTRAINDICATIONS**

- Hypersensitivity or allergy to Ondansetron
- Do not administer to children under 1 year of age
- Do not administer to pregnant patients in their first trimester

#### **MECHANISM OF ACTION**

Ondansetron blocks serotonin receptors in the central nervous system, preventing the vomiting reflex and reducing nausea.

#### **SIDE EFFECTS**

- Headache

#### **AUTHORIZATION**

**EMT:** Adult: IM injection or ODT PO; Pediatric: ODT PO

**AEMT:** Standing order

**Paramedic:** Standing order

#### **DOSAGE**

<table border="1" id="bkmrk-patient-type-route-d"><tbody><tr><th>Patient Type</th><th>Route</th><th>Dosage</th><th>Maximum Dosage</th></tr><tr><td>Adult</td><td>IV/IO/IM/PO (ODT)</td><td>4 mg</td><td>4 mg per dose</td></tr><tr><td>Pediatric ≥ 1 year</td><td>IV/IO/IM</td><td>0.15 mg/kg</td><td>Max 4 mg per dose</td></tr><tr><td>Pediatric (Weight 8–15 kg)</td><td>PO (ODT)</td><td>2 mg (split 4 mg tablet on score line)</td><td>2 mg</td></tr><tr><td>Pediatric (Weight 16–36 kg)</td><td>PO (ODT)</td><td>4 mg</td><td>4 mg</td></tr><tr><td>Pediatric &lt; 1 year</td><td>Not authorized</td><td colspan="2">N/A</td></tr></tbody></table>

##### **Administration Notes:**

- For IV/IO administration, give over 2–5 minutes to prevent rapid onset side effects.
- ODT (Orally Disintegrating Tablet) should be placed on the tongue and allowed to dissolve without chewing or swallowing whole.
- Monitor for signs of headache, which is the most common side effect.
- Use caution in pediatric patients and adjust dosage based on weight.