Diabetes is not a condition caused by sugar (glucose), but rather a condition where the insulin in our body is not working properly, or we are not making enough insulin. We like to explain insulin’s function using a “lock and key” analogy, where the key (insulin) unlocks the door to allow glucose from our blood to get to our muscle cells, providing energy.
Diabetic medications are described using the same model, which can be placed into three categories:
• Medications that help the key
• Medications that release the key
• Medications that replace the key
It must be said that the cornerstone of diabetes care should always be healthy eating and an active lifestyle. Medications are a supplement to those healthy habits.
Since 90 to 95 percent of people with diabetes have Type 2 (later-in-life onset), this discussion of medication almost exclusively caters to that population, with those meds that help or release the key. Type 1 diabetes uses almost exclusively insulin for treatment (replace the key).
Medications that help the key control blood sugar:
• Biguanides (Metformin)
• TZD’s (i.e. Actos, Avandia)
• SGLT2 Inhibitors (i.e. Invokana, Farxiga)
Medications that release the key:
• Sulfonylureas (i.e. glipizide, glyburide, glimepiride);
Meglitinides (i.e. Prandin, Starlix) are similar
to sulfonylureas in action.
• DPP-4 Inhibitors (i.e. Januvia, Onglyza, Tradjenta)
• GLP-1 Agonists (i.e. Byetta, Victoza, Tanzeum)
The gold standard for oral medications is Metformin (glucophage). Metformin helps the key, as it works mainly by stopping the liver from producing too much glucose from its storage and spilling that sugar into the blood stream. It can also improve the sensitivity of body tissues to insulin so the locks can be opened more easily.
Along with Metformin, medications that help the key include TZDs and SGLT2s. These diabetes prescriptions have a very low risk of hypoglycemia because they do not affect natural insulin production, but simply help insulin do a better job. TZDs are better at lowering blood sugar than SGLT2s, but the potential side effects are different: TZDs can cause water retention and weight gain, while SGLT2s work by allowing the patient to urinate more glucose out of body, which leads to water loss and potential weight loss. On the other hand, SGLT2s could lead to bladder and yeast infections as more sugar in urine can become food for bacteria/yeast to grow. TZDs should not be used in heart failure patients. SGLT2s are new to the market and may be cost prohibitive, where TZDs have many generic equivalent manufacturers and are quite inexpensive. You and your primary care provider should discuss which is the best option that matches your needs.
Now on to medications that release the key. Each class within this group are all considered highly effective, but since they allow for more of your own natural insulin to be produced, they carry a higher risk of low blood sugar than the previous group. Sulfonylureas, which have been around for decades, stimulate our pancreas to produce more insulin and are quite cheap for medications. This class from the group has the greatest potential to cause hypoglycemia. DPP-4 inhibitors have a lower risk of hypoglycemia, but come with a higher price tag. While DPP-4s have had some negative press recently with potential rare side effects, they are one of the safest classes of diabetes medications. GLP-1s are very expensive and only come in injectable form, but can also be a good choice for lowering sugar, especially in patients who need to lose weight since weight loss is common with this class. Many patients fear injections, so the manufacturers have marketed once weekly dosage forms. GLP-1s can cause a good deal of stomach upset in the first month, and low doses to start are recommended to get used to the drugs. The risk of hypoglycemia is lower, and they may benefit heart patients slightly more, perhaps due to the increased weight loss.
If you or someone you know is struggling with controlling blood sugars, and have already adopted a healthy lifestyle, a conversation is needed with your primary care provider/endocrinologist, pharmacist, diabetes educator, nurse and other health providers involved in your care. Here’s hoping the right key opens the door to good health and wellness!
Dan Heller is the patient care coordinator at Smith’s Food & Drug.