Emiston (8mg/4ml) Injection

✔️ Dosage & Administration

May be taken with or without food. For intravenous infusion, dilute with 50 mL of 5% dextrose injection or normal saline before administration.

Adult Dose

Oral

Chemotherapy-induced nausea and vomiting

• Highly emetogenic chemotherapy: 24 mg once, 30 minutes before chemotherapy.
• Moderately emetogenic chemotherapy: 8 mg 30 minutes before chemotherapy, followed by another 8 mg after 8 hours. Then continue 8 mg twice daily for 1–2 days after chemotherapy.

Radiotherapy-induced nausea and vomiting

• Total body irradiation: 8 mg 1–2 hours before each session.
• High-dose abdominal radiotherapy: 8 mg 1–2 hours before treatment, then every 8 hours for 1–2 days.
• Daily fractionated abdominal radiotherapy: 8 mg before treatment, then every 8 hours throughout therapy.

Postoperative nausea and vomiting

• 16 mg one hour before anesthesia.

Gastroenteritis-related nausea and vomiting

• 8 mg three times daily.

Pregnancy-related nausea and vomiting

• 8 mg 2–3 times daily.

Parenteral

• Chemotherapy-induced nausea and vomiting: 0.15 mg/kg IV over 15 minutes, administered 30 minutes before chemotherapy, then repeated after 4 and 8 hours (maximum 16 mg per dose).
• Postoperative nausea and vomiting: 4 mg IV/IM immediately before anesthesia or after surgery.

Rectal

• 16 mg suppository 1–2 hours before chemotherapy.

Elderly

No dosage adjustment is usually necessary.

Severe Hepatic Impairment

Maximum recommended dose: 8 mg daily.

Child Dose

Oral

Moderately emetogenic chemotherapy (4–11 years)

• 4 mg 30 minutes before chemotherapy, followed by doses after 4 and 8 hours, then 4 mg three times daily for 1–2 days.

Radiotherapy-induced nausea and vomiting (>12 years)

• Same dosage as adults.

Gastroenteritis-related nausea and vomiting (>1 month)

• 0.15 mg/kg body weight three times daily.

Parenteral

Chemotherapy-induced nausea and vomiting (>6 months)

• 0.15 mg/kg IV over 15 minutes before chemotherapy, then repeated after 4 and 8 hours.

Postoperative nausea and vomiting

• 1 month–12 years (<40 kg): 0.1 mg/kg IV single dose.
• ≥40 kg: 4 mg IV single dose.

Renal Dose

No dose adjustment is generally required in renal impairment.

✔️ Side Effects

Common

• Headache
• Fatigue
• Constipation
• Diarrhea
• Dizziness
• Drowsiness

Less Common or Serious

• Cardiac arrhythmias
• QT prolongation
• Hypersensitivity reactions
• Flushing
• Liver enzyme abnormalities
• Visual disturbances
• Severe skin reactions such as Stevens-Johnson syndrome
• Bronchospasm or anaphylaxis (rare)

✔️ Interaction

• May reduce the pain-relieving effect of tramadol.
• Rifampicin and other CYP3A4 inducers may reduce Ondansetron levels.
• Concurrent use with QT-prolonging medicines may increase the risk of arrhythmias.
• May increase hypotensive effects when used with apomorphine.

✔️ Contraindications

• Concomitant use with apomorphine due to the risk of severe hypotension.
• Hypersensitivity to Ondansetron or any component of the formulation.

✔️ Precautions & Warnings

• Use cautiously in severe hepatic impairment.
• May mask intestinal obstruction or gastric distension.
• ECG monitoring may be necessary in patients with electrolyte imbalance, congestive heart failure, bradyarrhythmias, or those taking medicines that prolong the QT interval.
• Use cautiously during pregnancy and breastfeeding.

✔️ Storage:

Store at temperature not exceeding 30ºC in a dry place. Protect from light and moisture.