Apomorphine

Apomorphine: Uses, Dosage and Side Effects

Overview

Apomorphine Stimulates emesis through D2 dopamine receptors in the chemoreceptor trigger zone.

Uses of Apomorphine

• Induction of self-limiting emesis within a few minutes of administration in dogs where vomiting is desirable, e.g. following the ingestion of a toxic, non-caustic substance.
• Emesis generally occurs rapidly and within a maximum of 10 minutes.
• If emesis is not induced following a single injection, repeated injections will also prove ineffective and should not be given.

Dose of Apomorphine in Dogs and Cats

Dogs:

• 0.2 mg/kg s.c. (authorized dose)
• 20–40 μg (micrograms)/kg i.v. (non-authorized dose and route but some evidence to suggest is at least as effective).

Cats:

Not recommended; xylazine is a potent emetic in cats and at least as safe.

Side Effects of Apomorphine in Dogs and Cats

• Apomorphine may induce excessive vomiting, respiratory depression and sedation.
• Dose-dependent hypotension can be seen.
• Ivermectin-sensitive (MDR1 mutation) collies may be more susceptible to the effects of apomorphine and for this reason, the drug should be avoided if possible in such animals.
• If use is unavoidable, then the dose should be reduced.

Contraindications of Apomorphine in Dogs and Cats

• Induction of emesis is contraindicated if strong acid or alkali has been ingested, due to the risk of further damage to the esophagus.
• Do not use in cases of gastric foreign bodies.
• Do not use in cases of poisoning due to pyrethroids.
• Induction of vomiting is contraindicated if the dog is unconscious, fitting, or has a reduced cough reflex, or if the poison has been ingested for >2 hours, or if the ingesta contains paraffin, petroleum products or other oily or volatile organic products, due to the risk of inhalation.

Some Notes:

• In the absence of compatibility studies, apomorphine must not be mixed with other products.
• Antiemetic drugs, particularly antidopaminergics (e.g. phenothiazines) may reduce the emetic effects of apomorphine.
• Additive CNS or respiratory depression may occur when apomorphine is used with opiates or other CNS or respiratory depressants.