By Elisa Black-Taylor
Onsior is a fairly new medication used to treat cat pain. Before this drug became available in June 2012, a cat owner had little else to choose from when their cat was in need of drug therapy. You had Metacam, which has proven to be at the least unpredictable and at the worst deadly. Or you had Buprenorphine, a drug 30 times more powerful than morphine and in the opiate family.
Onsior has a website that tells more about the drug, classified as an NSAID. It’s similar to meloxicam and celebrex used for pain management in people. Their company webpage states
“Pain delays recovery, impacts negatively on a patient’s well being, and disturbs the bond with its owner and also the veterinary team.”
The small, yeast-flavored 6 mg. tablets provide a full 24 hours of pain relief. It’s primary uses are for postoperative pain associated with orthopedic surgery, hysterectomy and castration in cats. Onsior reaches maximum concentration in only 30 minutes via the intestinal tract, and is eliminated from the blood within two to four hours via the biliary route.
Onsior is recommended only for three days. It’s usually given half an hour prior to surgery, then 24 hours later the cat gets a second dose, followed by the final dose 24 hours after the second dose. The drug is sold in a blister-pack holding three pills. The pills are around $3 each. For cats over 13 1/2 pounds, two tablets daily are required.
In a field study, the most commonly reported adverse reactions were surgical site bleeding, infected surgery sites, lethargy, vomiting, and appetite reduction. Onsior should not be used in cats that have a hypersensitivity to robenacoxib or known intolerance to NSAIDs. It also can’t be administered with any other NSAID or with corticosteroids.
The most common side effects are lethargy, vomiting, loss of appetite and increased bleeding time. Clinical studies on cats dosed up to 5 to 10 times the daily dose for 6 weeks to 6 months, reported no deaths and/or encountered clinical side effects resolved upon termination of medication.
I read several reviews where Onsior was used to treat arthritis in cats. This confused me, because the drug is marketed for short term use for mild to moderate pain. I don’t know how long term use would eventually affect a cat. Especially since it takes years for some drug companies to warn the public about negative consequences. NSAIDS are notorious for causing gastrointestinal upset. Hopefully it won’t cause something medical to pop up five or ten years down the road.
Having rescued several injured cats, we’ve used all three drugs for pain management. Although Metacam didn’t cause any side effects, I was on edge after reading up on it’s negative reviews. Our cat Sealy was on liquid Buprenorphine after his two operations. Since it’s a narcotic, it left him quite drugged. Other than that, he experienced no side effects. He sat in his cage and stared at us, or he ate. It was clear he was on strong medication. Sealy was on the drug for several weeks, and we “weaned” him off of it, being an addictive opiate.
The Onsior was definitely the clear winner, used after spaying. No side effects at all and they drug appeared to do what it claimed it could do-reduce pain. No “zombie cat” from using this drug. It will be the drug of choice, should any of our cats require short term pain medication in the future.
Have any of the readers used Onsior? I’m curious whether it’s been prescribed for long-term use for pain. It would be rather expensive, should a cat need to stay on it for longer than the three day recommendation.