The Difference Between Rimadyl and Metacam
Rimadyl and Metacam both belong to the class of medications known as nonsteroidal anti inflammatory drugs, which are prescribed for pain relief, for example:
Pain control during recovery periods following such surgeries as spey's, castrates, orthopedics.
Pain relief during recovery from tears.
Chronic pain management for joints
Palliative care
What are NSAIDS?
NSAIDS can reduce pain and inflammation, however they also have some less desirable effects such as reducing the production of substances that protect the stomach, stopping platelets from working as effectively, and reducing the amount of blood that flows to the kidneys by making the arteries that supply them constrict.
The cyclooxygenase (COX) enzyme is actually present in two different forms, COX-1 and COX-2, each with a similar but distinct set of actions.
COX-2 is the enzyme responsible for inflammation and fever
COX-1 performs other functions such as protecting the gastric mucosa (stomach lining) from the acid that the stomach naturally produces as well as clot forming.
BOTH reduce blood flow to the kidneys by constricting the arteries.
One of the problems with NSAIDS is that they block both types of the COX enzyme, so while inflammation and pain are reduced, so are some of the good effects of the COX such as protection of the stomach lining.
Rimadyl is the brand name for the drug Carprofen. Rimadyl is a COX-1 and COX-2 inhibitor, which means it inhibits both COX-1, the enzyme that promotes normal gastrointestinal and kidney function and COX-2, the enzyme that provides anti-inflammatory activity.
Metacam is the brand name for the drug Meloxicam. Metacam is a selective COX-2 inhibitor, meaning that it specifically targets COX-2, the enzyme causing pain and inflammation. Since COX-2 is mostly present at sites of inflammation, inhibiting this enzyme means that there are lower risks for stomach ulcers.
The two primary differences are that Metacam, unlike Rimadyl, is available as an oral suspension, and it was the first NSAID that was approved for use in cats.
Drug Interaction
Rimadyl and Metacam should not be used together as if there is an allergic reaction, it cannot be confirmed as to which drug the pet reacted to. They should not be combined with any other NSAID. Doing so will increase the risk for developing kidney or liver disease. Additional drugs that should not be used concurrently with Rimadyl or Metacam include:
Corticosteroids - gastro problems
ACE inhibitors - gastro problems
Phenobarbital - These two drugs interact such that neither may work well if they are used together.
Final Thoughts
There are many different schools of thought when it comes to choosing one drug over the other. For instance, Vet Dr. Hunt DVM feels that Metacam is safer as it offers lower chances for side effects affecting the gastrointestinal tract since it's a COX-2 drug, while Rimadyl is a COX-1 and COX-2 inhibitor, however she does point out that, ultimately, they are both NSAIDS