ORAL AGENTS IN THE CAT

It seems that in general cats experience a diabetes that is analogous to human Type II diabetes mellitus; that is, these cats are still able to produce at least some insulin. Many feline patients (up to 30%) are able to experience diabetic regulation using oral medications alone; however, there is no way to identify these patients without actually trying medication and seeing if it works. For most of the oral products we are about to review, the goal is simply to improve the response to insulin injections.

(Photocredit: Morguefile.com)

(Photocredit: NIH.Gov,
U.S. National Library of Medicine)

GLIPIZIDE (GLUCOTROL^®) 

Glipizide acts by maximizing the ability of the pancreas to make and secrete insulin. For some patients, this is all it takes to achieve diabetic control. There is some capacity for side effects (15% of cats taking this medication will get an upset stomach) plus the majority of cats will not be controlled with this medication alone. Glipizide is generally considered to be a last resort (i.e. when it is absolutely not possible to give insulin injections). The reason glipizide is not a first choice medication involves the way it works on the pancreas. Glipizide's process of maximizing insulin production also maximizes the production of an abnormal protein called "amyloid" leading to amyloid build up in the pancreas. Most cats became diabetic in the first place by having excessive amounts of amyloid in the pancreas so making more potentially leads to progression of the diabetes in the long run. For more complete information on this medication click here.

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via Wikimedia commons)

METFORMIN (DIABEX^®, GLUCOPHAGE^®, DIAFORMIN^®) 

This medication acts by increasing tissue sensitivity to insulin (i.e. it makes insulin stronger). Unlike glipizide, it cannot not cause blood sugar to drop too low but lethargy, vomiting, and appetite loss have been reported side effects in cats. It cannot safely be used in cats with kidney insufficiency, with ketoacidosis (or any other form of acidosis for that matter), or in cats where an iodine-containing radiographic contrast agent is going to be used in the next few days. Since ketoacidosis can come up unexpectedly in the diabetic pet, this product may not be a good choice. Feline studies are in progress but look promising for cats as a supplement to insulin treatment though drug interactions may be problematic. (Interactions have been noted with trimethoprim, ranitidine, cimetidine, furosemide, and digoxin.)

VANADIUM

This is a trace mineral present virtually everywhere. It seems to have insulin-like properties and minimal side effects potential but is not likely to be helpful by itself. The form that has been studied was vanadium dipicolinate which is not commercially available. The vitamin stores sell vanadium sulfate (vanadyl fuel®) but we do not know if it works as well as the dipicolinate form did in the research setting.

(original graphic by marvistavet.com)

CHROMIUM PICOLINATE

This product is a mineral supplement that can be found in many vitamin stores. It seems to potentiate the effects of insulin (i.e. the insulin becomes stronger). In cats, chromium picolinate would be used similarly to vanadium, as a supplement to insulin therapy.

(original graphic by marvistavet.com)

(Photocredit: NIH.Gov, U.S. National Library of Medicine)

ACARBOSE (GLUCOBAY®, PRECOSE^®)

This medication inhibits the digestive enzymes responsible for breaking down starches. Its use leads to a more gradual absorption of sugars after a meal which in turn leads to a more stable blood sugar level. The medication itself is not absorbed from the intestine and thus can be combined with other medications readily but it can produce some intestinal side effects: flatulence, weight loss, and diarrhea. Acarbose was originally developed as a treatment for obesity since it interferes with sugar absorption and should not be used in underweight cats. Acarbose must be given with food if it is to work.