GASTROINTESTINAL DRUGS CHAPTER 4 EMETICS Drugs that produce

GASTROINTESTINAL DRUGS CHAPTER 4

EMETICS

• Drugs that produce vomiting with the intent of removing an ingested toxin before it can be absorbed. – Indicated when vomiting is necessary and safe to induce. – Must be given within 4 hours of ingestion to be effective. – Do not use if animal is comatose, seizing, has depressed pharyngeal reflexes, in shock, dyspneic, or has bloat/torsion. – Do not use if substance ingested was caustic or could become lodged in the esophagus. – Remember that rabbits, rodents, ruminants and horses can’t vomit! • If you are unsure about inducing emesis, call the ASPCA Animal Poison Control at 888 -426 -4435, 24/7. You may be charged a $65 consult fee

Centrally Acting Emetics Act on the Chemoreceptor Trigger Zone and/or the Emetic Center

Apomorphine • Stimulates CRTZ • Morphine derivative, Class II controlled substance. • Emetic of choice in dogs • Poorly absorbed orally, so ROA is IV, IM, or in tablet form in conjunctival sac • Vomiting occurs within 10 minutes of injection, within 20 minutes of conjunctival application. Remember to flush eye after vomiting is achieved.

Xylazine (aka Rompun, Anased) • Sedative (non-controlled) and anesthetic that stimulates the CRTZ and Emetic center. • Very effective as an emetic in cats • IM injection that produces vomiting within 5 minutes – Emetic dose is lower than sedative dose • Reversible with Yohimbine

Locally Acting Emetic • Causes irritation of the GI mucosa

Hydrogen peroxide • Used as an emetic in dogs, cats, pigs, ferrets • 3% solution that can cause vomiting within 10 minutes when given orally. • Can result in gastritis, aspiration • Should use fresh bottle as it loses fizz after a few months • 1 tsp per 5 pounds. No more than 45 m. L. May be repeated once after 15 minutes.

ANTIEMETICS Chlorpromazine Metoclopramide Diphenhydramine, Dimenhydrinate Ondansetron, Dolasetron Maropitant citrate -Prevent or control vomiting -Usually do not treat the underlying cause of vomiting. -Given parenterally

Phenothiazine derivative. Chlorpromazine • Blocks receptors in the CRTZ that may also directly inhibit the Emetic center. • Tranquilizer, but antiemetic dose should not cause pronounced sedation. • Lowers the seizure threshold? ?