Diabetes mellitus (DM) is climbing at an “epidemic” rate. According to statistics gathered by the Center for Disease control, diabetes increased from 2.9 percent to 5 percent between 1980 and 2007, respectively. Today, almost 10 percent of the U.S. population is diagnosed with diabetes or at risk. Fortunately, DM is treatable, although not curable, with a selection of anti-diabetic drugs that have both advantages as well as disadvantages. Physicians choose the appropriate drug based on the individual patient.
According to guidelines of the American Diabetes Association, metformin hydrochloride (Fortamet) is considered the standard initial oral management. Failed diabetes treatment of behavior modifications, consisting of increased exercise and weight control, prompt physician recommendation for oral medications. Metformin belongs to a class of drugs called biguanides. They have several mechanisms that synergistically work to decrease glucose load in the blood. Metformin improves tissue response to insulin. Uniquely, metformin, the only available biguanide, inhibits gluconeogenesis or glucose production in the liver. It also works to decrease the intestines’ ability to absorb glucose. Nausea, diarrhea and metallic taste are some of the reported side effects, according to the National Institute of Health. Lactic acidosis is the most serious side effect, however, it is rare.
Sulfonylureas are the second step in the diabetic management plan. When metformin alone is not sufficient, these drugs may be added to the medication regimen or used alone. They are commonly used in conjunction with other drugs and have a side effect profile that patients tend to tolerate. Their disadvantage is their ability to cause hypoglycemia (too low glucose). Glyburide (Diabeta, Glynase) is a second generation medication that acts by increasing the release of insulin from the pancreas to lower blood glucose. Dosing may be given one to two times per day as its effects last 18 to 24 hours. Simpler dosing and weight loss are considered advantages of sulfonylureas. It is recommended that these drugs be taken at the same time everyday for the best results.
Glipizide XL (Glucotrol)
Glipizide is another sulfonylurea. It is also a second generation drug that acts in the same manner as Glyburide. It increases the output of pancreatic insulin by acting on pancreatic beta cells. The extended release version of glucotrol acts longer, lasting 24 hours rather than the 12 hours of the standard Glucotrol. Extended release medication may be dosed once a day, which means a reduced number of pills. This is an advantage especially for patients with other conditions and multiple medications. Dosing instructions encourage each dose be taken with the evening meal when sugar levels are the highest. Side effects include low blood sugar, weight gain, water retention and a slight risk for cardiac abnormalities.
Rosiglitazone belongs to the group drugs called thiazolidinediones. Thiazolidinediones improve the sensitivity of insulin receptors to insulin acting to reverse resistance. Thiazolidinediones may be used when there is a profound need to improve Hgb A1c. They show an improvement of one to two percent versus 0.5 percent seen in sulfonylureas reported by independent reviewers of the Australian Prescriber. However, they are not recommended for patients that have heart failure or the propensity to retain fluid as thiazolidinediones themselves cause fluid retention.
Acarbose is not a first-line or second-line drug. It is recommended when a slight improvement in Hgb A1c is needed to reach glycemic (sugar) goals. It can be used alongside other antidiabetic drugs because its mechanism of action is different, decreasing glucose absorption in the intestines. This drug belongs to the class of drugs called alpha-glucosidase inhibitors. It may cause nausea and diarrhea, significant enough that patients sometimes discontinue its use.
About this Author
Dr. Deleshia Kinney received her M.D. from Southern Illinois University School of Medicine. She began writing professionally when she started her own medical marketing and consulting firm. Since then she has been providing quality health care consulting, publications, and presentations to community health organizations including the American Cancer Society, Urban League, Illinois Public Health Association, and Illinois Department of Public Health.