Oral antidiabetic medications - Sodium-glucose co-transporter-2 (SGLT-2) inhibitors: Nursing pharmacology

Sodium-glucose transporter 2 or SGLT-2 inhibitors are medications used to treat type 2 diabetes mellitus, which is characterized by insulin resistance; this is when tissue cells have trouble responding to insulin in order to use glucose from the blood.

As a result, tissue cells starve for energy despite having high blood glucose levels, which is called hyperglycemia. Now, SGLT-2 inhibitors include canagliflozin, dapagliflozin, empagliflozin, and ertugliflozin. All SGLT-2 inhibitors end in -gliflozin, and they are taken orally.

Once administered, SGLT-2 inhibitors travel to the proximal convoluted tubules in the kidneys, where they block the sodium-glucose transporter or SGLT-2, which facilitates the reabsorption of 90% of glucose from renal tubules.

As a result, SGLT-2 inhibitors lead to an increased excretion of glucose in urine, known as glycosuria, which ultimately lowers blood glucose levels.

Now, all this glucose in the urine may favor microbial growth. For that reason, the most common side effects of SGLT-2 inhibitors are urinary tract infections, particularly yeast infections.

In addition, the decreased reabsorption of glucose in the renal tubules leads to an increase in the urine osmolality, causing more water to be lost in urine too.

This can result in urinary frequency and polyuria, as well as renal impairment or even failure; this is especially likely to affect clients who also take medications like diuretics, ACE inhibitors, ARBs, or NSAIDs, and could result in dehydration and orthostatic hypotension.

Other dangerous side effects of SGLT-2 inhibitors include hyperkalemia and euglycemic ketoacidosis. Some clients on SGLT-2 inhibitors may also present with reduced bone density, which increases the risk of fractures.

Finally, canagliflozin can increase the risk of lower limb amputation; while dapagliflozin and ertugliflozin may increase the risk of necrotizing fasciitis of the perineum.

Now, SGLT-2 inhibitors are contraindicated in clients with renal failure, or those undergoing dialysis, as well as in clients with a history of diabetic ketoacidosis.

SGLT-2 inhibitors should also be avoided while breastfeeding, and should be used with caution during pregnancy. Caution should also be taken in clients with hypotension, dehydration, as well as in children and elderly clients. Additional precautions should be taken in clients with adrenal, renal or hepatic disease.

Now, if your client with type 2 diabetes is prescribed a SGLT-2 inhibitor like canagliflozin, be sure to review their most recent laboratory test results, including blood glucose, hemoglobin A1c, electrolytes, as well as their renal and hepatic function. Also review the results of their most recent urinalysis.