Onsat 8

Indications
Onsat is a serotonin 5-HT3 receptor antagonist used for preventing nausea and vomiting associated with emetogenic cancer chemotherapy, radiotherapy, and post-operative procedures. It can be used alone or in combination with other treatments.

Description
Onsat is an oral soluble film designed to dissolve on the tongue within 20 seconds, making it easy to swallow without water. The film contains Onsat base, which is a selective 5-HT3 receptor antagonist.

Pharmacology

Onsat works by blocking 5-HT3 receptors, which helps control nausea and vomiting caused by chemotherapy, radiotherapy, and post-operative conditions. Its action involves both peripheral and central mechanisms.

Dosage

For chemotherapy-induced nausea and vomiting, adults and pediatric patients (6 months to 18 years) typically receive 8 mg or 4 mg doses in three 0.15 mg/kg doses, up to a maximum of 16 mg per dose. For radiotherapy-induced nausea and vomiting, adults take 8 mg orally 1-2 hours before radiotherapy, followed by 8 mg every 8 hours for up to 5 days post-treatment. For postoperative nausea and vomiting, adults are given 16 mg as two 8 mg films or 4 mg via injection 1 hour before anesthesia. Pediatric dosing varies, with injections used for those over 40 kg.

Administration

For oral soluble film, tear open the pouch, place the film on the tongue, let it dissolve within 20 seconds, and then swallow with or without liquid. Wash hands after use.

Interaction

Onsat does not induce or inhibit the cytochrome P-450 enzyme system but is metabolized by it. No dosage adjustment is needed for drugs that affect these enzymes.

Contraindications

Onsat is contraindicated in patients with hypersensitivity to the drug or its components and should not be used with apomorphine.

Side Effects

Common side effects include headache, constipation, and diarrhea, which are generally mild to moderate. Rare side effects may include anaphylaxis, bronchospasm, and tachycardia.

Pregnancy & Lactation

Onsat has not shown carcinogenic effects in animal studies and is not mutagenic. However, it is excreted in rat breast milk, so caution is advised during pregnancy and lactation.

Precautions & Warnings

Onsat should not replace nasogastric suction and may mask gastrointestinal issues in some patients.

Use in Special Populations

No dosage adjustment is needed for patients with impaired renal function or those over 65. In patients with severe hepatic impairment, a single 8 mg dose infused over 15 minutes is recommended. There is limited data on dosage for children under 4 years.

Therapeutic Class

Anti-emetic drugs

Storage Conditions

Store at temperatures below 30ºC, in a dry place, protected from light and moisture.