RE: Use of clopidogrel in cats on NSAIDs

Emily Ross — Tue, 10 Nov 2020 16:22:29 GMT

Thank you Chris for this great reply, very useful

RE: Use of clopidogrel in cats on NSAIDs

Chris Linney — Thu, 05 Nov 2020 22:18:25 GMT

Hi Emily,

Great pharmacology question and my answer is based on my practice, experience, and I how I approach this rather than based on studies.

I tend to avoid aspirin if considering the use of NSAIDs in cats. Aspirin can be well tolerated in cats but the risk of GI irritation in combination with the use of NSAIDs would lead me to explore other antithrombotics. Clopidogrel is shown to better than aspiring for secondary thromboprophylaxis in cats so I am comfortable to drop aspirin. The SuperCat study is comparing the NOAC rivaroxaban to clopidogrel and it will be interesting to see if this changes the current recommendations.

With regards to clopidogrel and NSAIDs, there is a theoretical increased risk of bleeding but with the client aware of this, and clopidogrel being the treatment of choice for ATE secondary prevention, I do use both if the cat needs NSAIDs and an anti-thrombotic.

There are studies in humans comparing various NSAIDs and their bleeding risk profile in the presence of clopidogrel; spoiler: it varies dependent on the NSAID as metabolism by the same cytochrome P450 enzyme means there are potential interactions. That said, the risks of any of these drugs increase with increasing intensity of treatment, and these risks have to be balanced against the benefits to be derived. Recurrent ATE is reported to be anywhere within on average 3 to 9 to 12 months, on the pessimistic 3 months, I accept the risk of interaction.

Long winded answer, but I would avoid aspirin and NSAIDs in cats, but I would and do use clopidgrel and concurrent NSAIDs where the latter are required. There would also be the consideration of other analgesics over NSAIDs depending on the indication.

Chris