Famotidine contradindicated in renal failure?

Re: Famotidine contradindicated in renal failure?

emma_j — Tue, 19 Aug 2014 15:54:55 GMT

That is interesting and useful Julien thanks.

Re: Famotidine contradindicated in renal failure?

Julien Bazelle — Tue, 19 Aug 2014 14:01:56 GMT

Hi Emma,

H2-antagonists are excreted by the kidneys. Their excretion is therefore impaired during CKD, even if the level of impairment varies with the severity of CKD. In moderate-to-severe cases of CKD (IRIS stages 3 and 4) it is therefore recommended to half the dose (e.g. ranitidine 1mg/kg instead of 2mg/kg) and monitor for signs of toxicities. I would also add that ranitidine (and possibly other H2-antagonist) has been associated with iatrogenic hypotension when given IV too quickly and one can assume that hypotension may be detrimental for the renal functions. Regarding effects on gastric pH, studies in cats and dogs have shown that H2-antagonists are less potent than omeprazole which is preferred in case of proven GI ulcerations.

However, famotidine is a valuable drug in the treatment of ulcerative gastropathy (CKD-induced or not). The formulation makes it an easy drug to give to cats vs omeprazole. The acceptance is also really good in my experience and I would not be afraid to use it when needed. Of note, a recent study had suggested that uraemic gastropathy is not commonly associated with mucosal ulcerations and questioned the utility of antacids in cats with CKD.

Sorry I forgot to add the link for the study: http://onlinelibrary.wiley.com/doi/10.1111/jvim.12342/abstract

Re: Famotidine contradindicated in renal failure?

Richard Carter — Wed, 06 Aug 2014 10:55:33 GMT

Long term antacids in cats may be a problem - apparently they do need the low pH to kill off various other bugs they eat and at east of England CPD last year the expert was recommending oid at most but preferably pulse therapy to prevent opportunistic bacterial and other overgrowths or not at all - penicillin for gastric ulceration with sucralfate etc if any ulcers

Re: Famotidine contradindicated in renal failure?

Martin Atkinson — Wed, 06 Aug 2014 10:27:09 GMT

[quote user="Anthony Todd"]Nothing causes more chaos in a practice than locums' [and they're usually wrong anyway] changing treatments, denigrating vets or treatments [/quote]To be fair Anthony in your case they're probably just trying to wean your patients off corticosteroid dependancy! So if I was your locum and you insisted on treating with steroids I probably wouldn't want to come back anyway.

Re: Famotidine contradindicated in renal failure?

Anthony Todd — Tue, 05 Aug 2014 20:04:27 GMT

[quote user="Martin Atkinson"]And this is one very good reason why I shouldn't be a locum because I would never agree with anyone else's treatment protocol! [/quote]

If you told the client rather than discussed it with the practice vets I'd never have you back!

Nothing causes more chaos in a practice than locums' [and they're usually wrong anyway] changing treatments, denigrating vets or treatments or commenting on cases past or present, without discussing it with the practice vets first.

And they always put it in the notes but often leave out what they've done themselves!!

And I suspect I'd be worse even than Martin......

Re: Famotidine contradindicated in renal failure?

Martin Atkinson — Tue, 05 Aug 2014 19:11:38 GMT

[quote user="emma_j"]In this instance the cat (good assumption, Martin!) was started on famotidine by the permanent branch vet, rationale being significant concern re gastric ulceration. It is pretty commonly used by the medics at our main hospital so is filtering out to the branches as well.[/quote] I only assumed it was a cat given I expected that your caseload of CKD cases would be the same as mine with 99% cats and a dog every blue moon.

However you still haven't really addressed the question which was: is there a genuine need for an antacid? - it seems to be a habit rather than an actual need. If so and the patients are asymptomatic then there seems little point dishing it out if there is a theoretical risk. So I would support the locum other than I would be miffed if my locum changed my treatment protocol without passing it by me first unless there were overriding concerns of immediate risk to the animals health.

And this is one very good reason why I shouldn't be a locum because I would never agree with anyone else's treatment protocol!

Re: Famotidine contradindicated in renal failure?

emma_j — Tue, 05 Aug 2014 09:49:00 GMT

Stephen yes I agree wrt the 'art of locumming!'. I am a 'floating vet' myself (I prefer 'roving' though!) so my job constantly involves picking up other people's cases, but at least within a defined group of branches so I know everyone personally and most of us have reasonable communication skills and work to similar standard/philosophies etc. There is only one of me to go round though so locums are needed as well.

In this instance the cat (good assumption, Martin!) was started on famotidine by the permanent branch vet, rationale being significant concern re gastric ulceration. It is pretty commonly used by the medics at our main hospital so is filtering out to the branches as well.

We've not had many clients saying they couldn't administer the famotidine, as far as I'm aware - we're tending to use the 5mg tabs from summit now so perhaps easier to administer than the quarter 20mg tabs which are a bit awkward. I agree about cerenia and use that a lot too. Zoetis must be cooking up a feline oral solution, there's a market for it.

Re: Famotidine contradindicated in renal failure?

Martin Atkinson — Tue, 05 Aug 2014 09:16:31 GMT

The first question that springs to mind is why the cat is on famotidine in the first place? - presumably for some vomiting/appetite issue that has been related to gastritis. It is very rare that I find a CKD cat that requires antacid treatment and if I did I would try Antepsin first, so are you just giving it as a precaution as a habit or because there is genuine concern?

Re: Famotidine contradindicated in renal failure?

Stephen Courtney — Mon, 04 Aug 2014 22:02:33 GMT

I have no such concerns but i also find it really hard to gt famotidine into renal cats on a sustained basis- clients tend to give up, and /i also feel unpalatable meds put cats off their food so I don't push it that hard. I fins if they have gastritis cerenia is easier to use - either a quarter or a half or a 16mg tablet . they often eat better then too.

the art of locumming should surely include not causing issues with the clients of the vet you are replacing....

Re: Famotidine contradindicated in renal failure?

Glen McIntosh — Mon, 04 Aug 2014 11:48:21 GMT

To be honest, I was unaware of any contraindications relating to renal disease either.

I had a quick look on google and there appears that for humans there is a concern that renal disease will decrease clearance of famotidine such that side effects become more obvious and dosages should be adjusted downwards in these cases, but there is no absolute contraindication. For example:

From http://www.rxlist.com/pepcid-drug/warnings-precautions.htm

"Patients With Moderate Or Severe Renal Insufficiency

Since CNS adverse effects have been reported in patients with moderate and severe renal insufficiency, longer intervals between doses or lower doses may need to be used in patients with moderate (creatinine clearance < 50 mL/min) or severe (creatinine clearance < 10 mL/min) renal insufficiency to adjust for the longer elimination half-life of famotidine (see CLINICAL PHARMACOLOGY in adults and DOSAGE AND ADMINISTRATION). Prolonged QT interval has been reported very rarely in patients with impaired renal function whose dose/dosing interval of famotidine may not have been adjusted appropriately."

But I have not seen any such concerns in the veterinary literature.