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Clevor™ Drops to Induce Emesis
By Sarah Doyle, DVM
For a veterinary clinician in an emergency setting or general practice, a common presenting complaint amongst patients is dietary indiscretion. A dog who gets into chocolate, grapes, or raisins, cloth material such as gloves, or, more recently, face masks – is at risk for adverse clinical signs. In certain circumstances, the problem can be immediately removed by inducing emesis to remove the object or toxic substance. In many cases, successful induction of emesis is a non-invasive way to either significantly reduce or even eliminate the patient’s risk of toxicity or obstruction. Inducing emesis can negate the need for referral to emergency centers or hospitalization for diuresis or endoscopy. For owners with financial concerns, successful induction of emesis can avoid a potential hospitalization expense.
Until recently, there was no FDA-approved drug to induce emesis in dogs. A variety of methods, such as apomorphine administration, were used instead. However, in the summer of 2020, the FDA approved ropinirole ophthalmic drops under the brand name Clevor, which have been proven effective in inducing emesis in dogs. The drug was approved in the European Union in 2018 and has since been used there in veterinary settings.
Clevor is distributed in single-use vials and administered in eye drops with dosage depending on a patient’s weight. It is a dopamine agonist which acts on receptors in the chemoreceptor trigger zone and induces fast-acting, short-duration vomiting in patients. If a single dose is not effective, a second dose can be repeated 20 minutes following the first administration.
A study in 132 client-owned dogs, with 100 receiving the drops and 32 receiving a placebo, proved that 95% of the dogs treated with Clevor drops vomited within 30 minutes of administration. The dogs were administered this medication approximately one hour after a normal meal (no foreign objects or toxic substances were given). Of those given the Clevor drops, 86% vomited after the first dose, while 14% required a second dose after 20 minutes had passed from the first administration.
A laboratory safety study was performed on 24 dogs that sufficiently proved the drug’s safety. Dogs who did experience side effects (outside of vomiting) were those that are seen commonly with other dopamine agonists, including tremors (3%), lethargy (41%), and tachycardia (14%). These adverse effects were found to resolve within six hours following administration. In addition, ocular-related side effects such as eye redness (51%), blepharospasm (19%), conjunctival discharge (30%), swelling (3%), protrusion of the third eyelid (38%) or corneal ulceration (1%) were observed. Contraindications for using Clevor, outside of the usual contraindications to inducing emesis, include seizures, central nervous system depression, ocular injury, or irritation.
When compared to apomorphine (another dopamine agonist usually given intravenously or intramuscularly), there are several differences, including a longer duration of emesis seen with Clevor (12 minutes in Clevor vs. 1 to 5 minutes for intravenously administered apomorphine). Instead of maropitant, which is sometimes used as an anti-emetic following apomorphine administration, metoclopramide given subcutaneously at 0.2 to 0.5mg/kg is recommended following Clevor administration. As Clevor is FDA-approved, there are more specific guidelines for recommendations, including an age minimum of 4.5 months and a weight minimum of 1.8kg. Anecdotally, while apomorphine usually causes two to three episodes of emesis and then patients quickly return to normal, making it often unnecessary to administer maropitant, Clevor drops tend to last longer and require administration of metoclopramide to alleviate symptoms in a timely manner. Apomorphine remains a good option for the clinician in cases of patients with ocular disease or injury, but with an FDA-approved medication available, the use of Clevor drops should be considered as a first line.
Those administering Clevor drops should be aware of adverse reactions in the case of human exposure, including headache, nausea, vomiting, hypotension, drowsiness, or dizziness, and medical attention should be pursued to those who experience accidental exposure to the drops.
Highlight of some relevant differences between Clevor drops and apomorphine.
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Karen Todd-Jenkins, VMD; “Finally, an FDA-Approved Drug for Canine Vomiting…no, Not for Stopping It; for Initiating It.” DVM 360, MJH Life Sciences, 16 June 2021, https://www.dvm360.com/view/finally-an-fda-approved-drug-for-canine-vomiting-no-not-for-stopping-it-for-initiating-it.
Kelley, Kylie. “Pharmacist’s Corner: Clevor (Ropinirole) vs. Apomorphine for Emetic Use in Dogs.” Pharmacist’s Corner, University of Illinois College of Veterinary Medicine, 28 July 2022, https://vetmed.illinois.edu/2022/07/27/pharmacists-corner-clevor-ropinirole-vs-apomorphine-for-emetic-use-in-dogs/#:~:text=Though%20both%20Clevor%20and%20apomorphine,currently%20have%20any%20age%20restrictions.
Medicine, Center for Veterinary. “FDA Approves Clevor to Induce Vomiting in Dogs.” S. Food and Drug Administration, FDA, 6 June 2020, https://www.fda.gov/animal-veterinary/cvm-updates/fda-approves-clevor-ropinirole-ophthalmic-solution-induce-vomiting-dogs.
Suokko M, Saloranta L, Lamminen T, Laine T, Elliott J. Ropinirole eye drops induce vomiting effectively in dogs: a randomized, double-blind, placebo-controlled clinical study. Vet Rec. 2020 Mar 7;186(9):283. doi: 10.1136/vr.104953. Epub 2019 Aug 13. PMID: 31409749; PMCID: PMC7063390.