Rapamycin for my Cats?

Really interesting story here about CKD and how low dose niacin and sodium bicarb (baking soda) actually works to get rid of the phosphorous and cure it:

https://orthomolecular.org/resources/omns/v17n22.shtml

I don’t know what dose to give the cats.

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That’s a good study, and a good result. The question is at what point you administer the drug/supplement. From the study, it seems the result is validated in cats that already have substantially impaired kidney function with some comorbidities. If I had a cat in that situation, I’d certainly feel comfortable administering this substance. However my cat is in much earlier stage, with just one biomarker out of whack, so I’m looking at much more of a preventative treatment, and that’s what guided me toward dapagliflozin.

However without a doubt, CKD is a highly prevalent condition in older cats, and trying to get ahead of the problem is quite justifiable, if the intervention has multiple benefits and relatively low risks.

I’m really hoping that rapamycin + dapagliflozin are of a substantial net benefit, but I do remain vigilant in monitoring the potential impact to the best of my ability.

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Interesting, so I just searched. I also see they mention calcium carbonate, too, which is one of the ingredients in Epakitin (a phosphorus binder for cat food).

FWIW, if giving Epakitin, one must closely monitor calcium levels in their cats because calcium carb can cause hypercalcemia In some cats. (I don’t give this)

Using aluminum hydroxide has been recommended by my vet and it’s the most widely used binder in the Feline Chronic Kidney Disease facebook group (lots of well informed people in there and I owe so much to them. I highly recommend using them as an additional resource. Even my vet has learned a lot from them… I’d run things by her and she’d research ). Aluminum hydroxide and low phosphorous foods (not rx foods) have been enough to keep the levels of our cats low, most of the time. The cat we lost last year only had high levels I had trouble containing during his last month.

A phenomenal source for those learning about CKD is Tayna’s site. This page talks about various binders and dosing. It includes niacin vs niacinamide.
https://felinecrf.org/phosphorus_binders.htm

FWIW, if anyone is using aluminum hydroxide, I learned that the one offered by Thriving Pets (a compounding pharmacy) is more pure, so I use that vs the brands you can get elsewhere… it’s all good though.

@Bicep do share anything else you learn, but here is another good thing to read (I am familiar with this person) Feline CKD: Niacinamide for Phosphorus Control - Raw Feeding for IBD Cats
Does your cat have CKD or are you also looking at prevention?

On niacin,
I see it’s mentioned out there in the interwebs and I just saw one person’s comment about it in the FB group that I’ll share. Obviously this is only one person, but it is a thing, even if not common.

As a reply to someone saying they are going to start niacin, this person said
“I do want to flag that thrombocytopenia (destruction of platelets) is the one known side effect of niacinimide and some cats do experience it (mine did). If you go this route it’s important to watch for signs of low platelets (excess bleeding, little purple spots on skin, extra pale nose) and get a blood test (CBC) after not too long to make sure your cat doesn’t have this reaction. Many don’t! But just want you to be cautious”

Also on niacin (and chitosan, which is an ingredient in the aforementioned Epakitin), I now see it’s in the food my vet told me about. The person who created this food is very respected. It’s not actually that low in phosphorus and the first ingredient is rice (until I used this, my cats had never had grains). I only had one cat who was willing to eat this food, the others wouldn’t touch it, but it’s an interesting food that it contains niacin and a binder) Kidney Support Diet – For Cats – Medicus Veterinary Diets

I’m also so glad you had me doing another deep dive today because I see Catney One has finally been made available last month (a binder and also mentioned on the Tanya site). I’m getting my hot little hands on this right away!!! It’s from the makers of Porus One, which is highly recommended for ckd. Cost is sadly prohibitive for many :frowning:

I am also dosing my Kevin. He is definitely feeling perkier for an obese 9 year old. 1 mg per week.

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AWWW, @Dreamdoc, I can’t get enough of Kevin!!!

Hey everyone and @RapAdmin … so, I just pilled my two cats, but my 3rd eats his rapa in a bowl of treats (pilling would be too stressful for him and not worth it)…

He normally swallows it whole, but today I heard the crunch. Is he still getting some benefit? I fear just giving him another whole one and overdosing him if he is getting a partial dose after chewing it.

So, if you were me, would you just wait until next week, or give him another half, knowing he then only gets a partial dose of each one (because he did not swallow either pill in tact).

Thx!

Clearly, there was plenty of Kevin to go around.

I would not give another dose, I would just dose again next week. Consider putting butter on the pill. That will make it harder for him to take a bite and easier for it to slide down.

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I don’t think it makes a much of a difference either way, but skipping a dose is safe and easier.

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Sodium-glucose co-transporter 2 inhibitors: a pleiotropic drug in humans with promising results in cats

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Has anyone ordered from here?

My current vet is unaware of Rapamycin for cats other than Felycin for HCM. It looks like there are no completed studies about using it for kidney disease. My cat has hyperthyroid and CKD and a possible kidney tumor. When we fixed the hyperthyroid her white blood cell counts shot up and I expect it’s possible her CKD values could get worse again too which were masked by the hyperthyroidism.

I’m going to ask her again about the research but I also was interested in just trying to get my hands on some rapamycin on my own. Looks like the 1mg should be Ok for her maybe a little bit on the high side because she is tiny at 6lbs. I’m seeing some stuff on the Helping Pets Live Longer site about the enteric pills that gives me pause, but it looks like not even all the human pills are enteric coated and some of you are crushing the pills and still seeing results? I don’t know what to think about this statement that rapamycin is useless unless it’s somehow acid resistant or enteric coated.

Do you know if Felycin can be prescribed off label, say for cats with CKD or cancer? My vet is familiar with it but only in the context of HCM

I highly recommend Helping Pets Live Longer. Been working with Dr. Kevin for about a year and a half now and the rapamycin I got through him helped stopped progression of my cats severe heart disease (dilated cardiomyopathy) with some signs of reversal. He sells it in a liquid oil solution that helps bypass the stomach acid but he might also offer Felycin now that it’s on the market.

I can now report on the effect of rapamycin on my cat skin cancer. The cat in question is a white cat currently 15 years old, who developed SCC (Squamous Cell Carcinoma) skin cancer already back in 2021, on his lower eyelid, but it was not diagnosed as cancer until much later (2024). Only in retrospect did we realize that his tearing eye was the first sign back at the end of 2021. A formal biopsy was conducted much later from another skin cancer patch on his ear. In any case, by 2024 the cancer had spread all to his ear and the vet recommended removing part of the ear. That surgery was done in May 2024. However, the cancer kept spreading. It was pretty bad on his lower eyelid, but no surgery was possible in that location. Meanwhile, the cancer spread to his other ear, and very rapidly started to develop all over his head and neck, and even in the shoulder area. The vet said surgery was pointless as the cancer will keep spreading and you can’t remove all of the skin from the cat.

By January of 2025, the cancer was very extensive, with large open hairless sores 2-3 inches in size on his neck and multiple points on his head and little patches on his nose. The vet could do nothing. Surgery was out and he had no drug recommendations. Just watching the extremely rapid progression all over his skin was extremely stressful to us, although the cat didn’t seem to be in pain. If he shook himself, blood would spray all over the walls. As you can imagine this was very hard to watch.

I was of course aware of rapamycin use against cancer, and finally, I felt that with no remedies from the vet we had nothing to lose and we’d try rapamycin as a last resort. We started him on 1mg a week, Biocon Eris Sirolimus from India on February 2nd 2025. Obviously, watching him so closely and with all the psychological pressure, I was acutely aware of the placebo effect (on us, not the cat, lol), so I was very careful reaching any conclusions, but the rapamycin seemed to work almost immediately. My wife claimed she could see slight effects already in the first two weeks, though I refused to believe such fast action. Nonetheless, over the next few weeks, the progress started becoming undeniable.

Friends, it was insane. Literally unbelievable. Had I not seen it with my own eyes, I would not have believed it as “too good to be true”. The cancer started retreating. It completely vanished from his neck - the huge open sores - and gradually started disappearing from his head. All this within the span of a few weeks. The only hard patches were the original eyelid and where it first spread, the ears. But finally in time, it disappeared from the ear too.

This felt like a miracle. Literally within 3-4 months the cancer retreated dramatically. The vet could not believe it, but he remembered how it looked before, plus we had some photographs. We told him about the rapamycin because we wanted him to have something to offer other cats in a similar situation (funnily he said he’d recommend trying rapa to his friend - human obviously - for the SCC on his face!).

However, unfortunately, I cannot announce a 100% success. The eyelid - original location - initially stabilized, but then started looking worse again. So, at the start of July of this year, we bumped up his dose to 2mg a week, because this would be roughly inline with the use of rapamycin cleared by the FDA for cats (obviously for a different indication) of a dose of 0.3mg per kg of body weight.

Unfortunately, there has been no progress with the cancer. It is still on his eyelid, and there are even occasional breakthroughs on his head and nose, though these usually go away after awhile. The eyelid is unfortunately not good. So for now, I can say that rapamycin definitely works on SCC in our cat, but not 100%.

My takeaway is that we should have tried rapamycin immediately the moment we saw something that we suspected was cancer. Had we done this when it was still confined to just his eyelid and ear, I’m convinced we would have had a very good chance to eliminate it altogether and then keep him on a maintenance dose. Clearly, it would have spared him having his ear cut off, because rapa cleared the other ear that was going in the same direction. As always with cancer YOU WANT TO CATCH IT EARLY in diagnosis and treatment.

Why did we not do so earlier? First, we were a little bit avoidant in diagnosing skin cancer, putting down the little sores to his scratching (plus he had other complications in his ear). That was wishful thinking. We should’ve suspected cancer immediately - he’s a white cat who loved to sun himself. Second, you have to go to the vet first, and not try to cure the condition yourself. It felt irresponsible to bypass the vet - he’s the first line. Had things gone wrong, we’d feel responsible for damaging the cat’s health by not going to the vet first. And we had to agree to the vet’s treatment - he’s seen thousands of cases, we are in no position to second-guess established veterinary practice.

But it’s the results that count. He lost half his ear to surgery and the cancer kept spreading. No further remedies were offered. Cancer was spreading very rapidly. In that scenario, we felt justified trying our own protocol. I now believe we’d have been much better off putting the cat on rapamycin from the get-go, not waiting for the cancer to spread and trying the conventional veterinary interventions which the vets themselves admit are only stopgap and no actual solution.

In fact, we should have put the cat on rapamycin regardless of cancer. Even if he was perfectly healthy. Because the balance of evidence says that animals benefit - we saw that proven in mice, and with trials in dogs, marmosets etc., I think the evidence says to go for it, unless there are counterindications (your cat is immunocompromised, has bacterial infections etc.).

I have to agree with Matt Kaeberlein. In his latest interview on his podcast he makes the point that prevention is the obvious best practice - as in his analogy do you wait for the car to break down and then going to the mechanic to try to get it fixed, or do you take care of your car before it breaks down, change oil etc. In his view it’s obvious that prevention is what you should choose (he even called someone who’d rather wait to get sick “a moron”).

So, in the case of my cats I’m a moron. I suppose there is a psychological barrier too. I am happy to make a choice for myself - heck, I’m on rapamycin, empagliflozin and other drugs and supplements. But it’s different when you are responsible for someone else. That’s why I’m very reluctant to recommend rapamycin to my friends - in fact, I only briefly mentioned the science and data behind rapa to one friend - because it’s not my body. Obviously, in the case of loved ones you would at least mention the possibility and the options (but never pressure anyone to take any medication!) - MK himself said that he’d let close friends and family know of the options. So in the case of your pets - should you make that decision? It’s complicated, because you already make the decisions about their health in other ways anyway.

In fact, this has motivated me to get my cat (the same one), on dapagliflozin - I wrote a post higher up in this thread my detailed reasoning and studies, so I won’t repeat them here. However, the point is that I’m being more proactive in the case of his kidneys and possible pleiotropic benefits. Just today I got the results of blood and urine tests after the cat being on dapagliflozin since early July. His kidney numbers have gotten better, but still not perfect. His proteinuria - the thing that worried me most - was cut in half, so it’s progress, though still not perfect (was +2, now +1). Again, the vet - as most vets - have no remedy and nothing to offer to slow down kidney disease and deterioration. So what do I lose here? We know that SGLT2i slow kidney deterioration - just because doctors don’t know that, as in the case of rapamycin does’t mean we should waste time we and our companion animals don’t have. One day, they’ll wake up to SGLT2i (as they’re slowly doing for rapamycin), but by then it’s too late. Our choice is to act now, or watch helplessly.

Yes, there is risk involved. So you calculate the risk and make the best decision you can. Even with dapagliflozin with my cat I have to modify. The lab results came back very good (all of his biomarkers look good, with big improvements in liver markers also!), but he’s been slowly losing weight (I suspect due to the glucose loss), and he’s dipped just below 10lbs (from 12lbs when he was a bit overweight). I don’t want him to lose more weight, so I am cutting back on the dapagliflozin 5mg to three times a week from daily.

We’ll continue to monitor his health and how he’s doing. But I am now more willing to intervene if the vet has no solutions to offer. The principle for humans applies to pets: first do no harm. So I check and doublecheck and keep doing research. I will not try anything risky, but also feel I must get ahead of the disease, not just wait for it. YMM.

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If it were mine, I would up the rapamycin dosage. In the case of animal studies and humans, high intermittent doses are unlikely to cause permanent harm. Other than surgery, SCCs are not easily cured, especially around the eyes. There are topical treatments available, but they shouldn’t be used around the eyes. So sorry for your predicament. Our pets are like family.

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Thanks! Yes, dose escalation remains an option. My preliminary plan is to watch and wait, and if the eyelid deteriorates, up the dose. For now he’s within the FDA cleared dose.

So stressful and hugs to your cat. Thank you for sharing your experience.

My cats have been on rapa since jan and they became noticeably perkier.

Since then, just a couple months ago, we added the aminavast supplement I previously mentioned (only one pill a day dumped into their food) and I switched their phosphorus binder to Catney, from aluminum hydroxide (one cat seems to have more of an appetite on it). One had already been on Porus One for over a year, in addition to them both getting daily sub q fluids.

I can’t begin to tell you which things are doing the heavy lifting, but at 17 and 18 years old with advanced CKD, they are both aging backwards. I kept thinking they were near the end, but nope, not anymore.

Back to you.

My 17 year old was diagnosed with mast cell almost two years ago and she was put on immunotherapy. She does really well on it. As instructed, I also give her an anti acid with it. Earlier this year we switched to imatinib immunotherapy and it’s working even better for her.

I googled and it appears imatinib is something that can possibly help SCC. The nice thing is, unlike more aggressive treatments, this does not alter the quality of her life one bit. She is healthier now than she was two years ago. Heck, she is even healthier than she was two months ago! It’s very noticeable based on how much she travels throughout the house.

(They are also getting solensia and Adequan injections).

Did your vet discuss immunotherapy with you? My cat has an oncologist but she has told me (as everyone does) that my IM vet is so good, just have her manage her treatment. I wouldn’t think traditional vets would have that much personal experience with prescribing immunotherapy. Their other vet just sent me to the oncologist.

As I’ve mentioned, but I’ll put it out there again, if you don’t have anyone to discuss this with, my vet does remote consults and you can have a phone or zoom visit. She is also very familiar with sglt2 and rapamycin. She did not want me to give my cats sglt2 due to losing weight and dehydration (we previously discussed this and your cat is at a different place, but I mention this for the benefit of others who might have cats with more advanced ckd where hydration and weight loss is already a challenge)

And ditto on the guilt… I lost my favorite cat last august and I only wished I had put him on rapa that might have made his last few months a little better. I was still fairly new to it and was not comfortable enough to give it to my old cat with so many comorbities. Woulda coulda shoulda

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"Imiquimod (Imiquad) cream is FDA-approved for treating human skin cancers, such as basal cell carcinoma and actinic keratosis. While it has shown effectiveness in humans, its use in animals, including cats, is less well-documented and may not be officially approved.

Some veterinary dermatologists may use it off-label for certain skin conditions in animals, such as squamous cell carcinoma in cats, but its safety and efficacy for these uses would be determined on a case-by-case basis by a veterinarian. Cats can be sensitive to certain medications, and imiquimod might cause side effects such as skin irritation, redness, or inflammation.

If you’re considering using Imiquad for a cat, it’s crucial to consult with a veterinarian who can assess the specific case and provide the appropriate guidance."

“Imiquimod might cause side effects such as skin irritation, redness, or inflammation.”
Of course, all topical treatments of skin cancer have this effect.

You may want to search for a veterinarian who specializes in skin diseases and/or oncology.

Imiquimod (Imiquad) cream is expensive, but I have some on hand just in case.

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Thank you. Our vet didn’t think that immunotherapy was indicated for the SCC our cat has, but we didn’t discuss imatinib. At this point it’s watch and wait. If it starts going downhill again, it’ll be time to look for more drastic measures, maybe imatinib in addition to escalating rapa dosage.

If the weight loss doesn’t stop, I’ll have to stop the dapagliflozin, because below a certain point, weight loss becomes dangerous to cats, especially the liver. Fortunately right now his results from today show stellar values for the liver (in fact improved). Atm. I am cutting back dapa to 3 times a week, but if that doesn’t work, I’ll stop dapa and look into other means of protecting the kidneys.

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FYI, I just received this in my inbox.

Apparently PetSpan is no more, and Dr Kevin is offering free consults (very smart!)

Here is the body of the email

And here is the live link

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Thanks I’ll try that for my cat

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