Ondansetron HCl 🌟🤢

🐾 Ondansetron HCl 🌟🤢

5-HT3 receptor antagonist and its role in alleviating vomiting in animals. 🌿🐶🐱

Prescriber Highlights

Uses and Indications

Pharmacology and Actions

Pharmacokinetics

Contraindications, Precautions, and Warnings

Adverse Effects

Reproductive and Nursing Safety

Doses

Monitoring

Client Information

Chemistry and Synonyms

Storage and Stability

Dosage Forms and Regulatory Status

💊 Prescriber Highlights:

- Ondansetron HCl is a 5-HT3 receptor antagonist used to treat severe vomiting.

- It appears to be well tolerated in dogs.

- Generic dosage forms of Ondansetron are now available, providing more affordable options for treatment.

🌟 Uses/Indications:

Ondansetron HCl is primarily used as an antiemetic when conventional antiemetics prove ineffective. It is especially valuable when administering cisplatin or when dealing with causes of intractable vomiting. However, its use in cats is somewhat controversial, with differing opinions regarding its suitability for this species.

🔬 Pharmacology/Actions:

Ondansetron HCl works by acting as a 5-HT3 receptor antagonist. These receptors are present in vagal nerve terminals and the chemoreceptor trigger zone (CTZ), both peripherally and centrally. While it's unclear whether Ondansetron's effects are mediated centrally, peripherally, or both, it demonstrates efficacy in reducing vomiting.

🔬 Pharmacokinetics:

Although limited pharmacokinetic data specific to veterinary species is available for Ondansetron, it is well absorbed from the gastrointestinal tract in humans. The drug undergoes some first-pass hepatic metabolism and exhibits a bioavailability of approximately 50-60%. Peak plasma levels are reached about two hours after oral administration. Ondansetron is extensively metabolized in the liver, with elimination half-lives of about 3-4 hours, which may be prolonged in elderly patients.

⚠️ Contraindications/Precautions/Warnings:

- Ondansetron HCl should not be used in patients who are hypersensitive to the drug or other agents in its class.

- It may mask ileus or gastric distention and should not replace nasogastric suction.

- Caution is advised when administering Ondansetron to patients with hepatic dysfunction, as the drug's half-life may be prolonged.

- Herding breeds with a gene mutation causing nonfunctional P-glycoprotein should receive Ondansetron with caution due to its potential neurotoxicity.

💊 Adverse Effects:

Ondansetron HCl is generally well tolerated. Possible adverse effects include constipation, extrapyramidal clinical signs, arrhythmias, and hypotension, with an incidence in humans of less than 10%.

🤰 Reproductive/Nursing Safety:

The safety of Ondansetron during pregnancy has not been clearly established, although high-dose studies in rodents did not show overt fetal toxicity or teratogenicity. In humans, the FDA categorizes the drug as category B for use during pregnancy, indicating that animal studies have not demonstrated risk to the fetus, but there are no adequate studies in pregnant women. Exercise caution when administering 5-HT3 antagonists to nursing patients as Ondansetron is excreted in rat maternal milk.

💊 Doses:

Note: The following dosage information is provided for informational purposes only. Always consult a veterinarian for the appropriate dosage for your specific pet.

🐶 Dogs:

- Adjunctive treatment of pancreatitis: 0.1-0.2 mg/kg IV slowly

- When conventional antiemetics are ineffective: 0.1-1 mg/kg PO every 12-24 hours or 30 minutes before and 90 minutes after starting cisplatin infusion

- Intractable vomiting associated with Parvo enteritis: 0.11-0.176 mg/kg IV every 6-12 hours (based on patient response)

- Antiemetic use: 0.1-0.2 mg/kg IV every 6-12 hours or 0.1-1 mg/kg PO every 12-24 hours

- Adjunctive treatment of uremia: 0.6-1 mg/kg PO or IV every 12 hours, often combined with metoclopramide

🐱 Cats:

- Intractable vomiting when other drugs are ineffective: 0.22 mg/kg 2-3 times a day

- Antiemetic for intractable vomiting: 0.1-0.15 mg/kg slow IV push every 6-12 hours as needed

- Adjunctive treatment of severe pancreatitis: 0.1-1 mg/kg PO or IV every 12-24 hours

👀 Monitoring:

Regular monitoring of clinical efficacy is important to assess the response to Ondansetron HCl treatment.

💡 Client Information:

Ondansetron HCl is typically used in inpatient settings to treat serious vomiting cases. It's important to follow the veterinarian's instructions and ensure proper administration and monitoring.

🧪 Chemistry/Synonyms:

Ondansetron HCl dihydrate is a white to off-white powder soluble in water. It is also known as GR-38032F or ondansetroni hydrochloridum. The brand name for Ondansetron HCl is Emistat.

🌡️ Storage/Stability:

Unless otherwise labeled, store oral products in tightly closed, light-resistant containers between 2-30°C. The injection should be stored between 2-30°C, protected from light.

💊 Dosage Forms/Regulatory Status:

Ondansetron HCl is not specifically labeled for veterinary use. However, it is available in various human-labeled forms, including tablets, orally disintegrating tablets, oral solution, and injections.

Disclaimer: The information provided here is for informational purposes only and should not replace professional veterinary advice. Always consult a veterinarian for accurate diagnosis and appropriate treatment options for your pets.