Some types of medication for diabetes do tend to lead to weight gain. This is especially true of the classes of medications known as thiazolidinediones, sulfonylureas, meglitinides, and insulin itself. Mem- bers of each of these classes of medications have been described in Table 4 (see Question 41). These types of medications all have proven effectiveness in lowering blood sugar and controlling diabetes and have an important place in its management. However, weight gain is definitely an undesirable side effect associated with them. The ways in which weight gain can be minimized or prevented include using, whenever possible, medications that do not cause weight gain, such as the classes known as DPP-IV inhibitors or α-glucosidase inhibitors. Another option is to take medications that are actually known to cause weight reduction in many people who take them, such as the classes known as biguanides, incretin mimetics, or synthetic amylins (e.g., pramlintide). Some representatives of these classes can also be found in Table 4. If medications known to cause weight gain must be used, then your doctor will try to use them in the lowest effective dose, often by combining them with other types of medications.
Finally, it is important to remember that adhering to a diet and exercise plan is just as important when you are taking pills for diabetes as it was beforehand. Many patients who are prescribed pills are told that they have failed diet and exercise. This is not entirely true. The diet and exercise may be making an important contri- bution to the control of the diabetes, but is not quite enough to control the blood sugar adequately. This important contribution will be lost if the program is not continued and some weight gain in people who start pills or injections for their diabetes is undoubt- edly due to this.