November 2, 2013

SGLT2, A New Class of Diabetes Drugs

A new class of diabetes drug was approved in 2013. The class is SGLT2 and the brand name is Invokana with as generic name of canagliflozin. Canagliflozin is to improve glycemic control in adults with type 2 diabetes in cooperation with diet and exercise. The drug has been studied as monotherapy and in combination with other common treatments for type 2 diabetes including metformin, sulfonylurea, pioglitazone, and insulin. The manufacturer is Johnson and Johnson.

The FDA is requiring J&J to perform five post marketing studies with canagliflozin, including a cardiovascular outcomes trial; an enhanced pharmacovigilance program to monitor for malignancies, serious cases of pancreatitis, severe hypersensitivity reactions, photosensitivity reactions, liver abnormalities, and adverse pregnancy outcomes; and a bone safety study. This is more than any previous drug and indicates the FDA is being tough on J&J.

The most common side effects include vaginal yeast and urinary tract infections which if treated early have not been difficult to manage. The FDA states that canagliflozin is not to be used to treat people with type 1 diabetes, people with diabetic ketoacidosis, or people with severe renal disease. Over 10,000 patients in clinical trials with type 2 diabetes shows that canagliflozin improved A1C levels and fasting plasma glucose levels.

SGLT2 is short for sodium-glucose co-transporter-2 inhibitors that lower blood glucose by blocking the reabsorbtion of glucose and passing it in urine. A clinical study of patients at especially high risk of cardiovascular disease showed that within the first 30 days, 13 patients taking canagliflozin suffered a major cardiovascular event compared with just one patient taking a placebo. After that, the imbalance was reversed. The drug also caused a slight increase in unhealthy LDL cholesterol.

Canagliflozin comes in 2 different pill sizes, a 100-mg tablet and a 300-mg tablet. It is recommended that patients should take it first thing in the morning before breakfast. As an analogy, I think of giving this drug a little bit like using a diuretic, because it is going to make them a little bit glycosuric (excretion of glucose in the urine) and it will have a little bit of a diuretic effect. Therefore, take it in the morning so patients don’t urinate all night long when they're getting used to it. Clinicians should start patients at 100 mg. If that dose is tolerated then up-titrate to 300 mg, and that's the dose the patient continues to take.

David Spero writing for Diabetes Self Management has an excellent discussion on SGLT2 and what he finds as concerns.   Read his blog here.

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