Two-Med Combo to Prevent Diabetes

Type 2 diabetes rates lower in people with prediabetes who took phentermine and topiramate

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) For people who show signs of type 2 diabetes, controlling weight may be a key part of keeping their condition from getting worse. A recent study suggests that one combination medication could play a role in preventing diabetes.

Researchers tested Qsymia — a combination of an appetite suppressant and an epilepsy medication — on overweight or obese patients who had some, but not all, symptoms of diabetes.

They found that the medication led to weight loss and reduced the risk of developing type 2 diabetes. Patients taking Qsymia also had improvement in other aspects of their health, like reduced blood sugar.

The researchers suggested that this medication, coupled with lifestyle changes, could be an effective way to lose weight and prevent the progression of diabetes.

"Talk to your doctor about weight loss if you have prediabetes."

Timothy Garvey, MD, of the Department of Nutrition Sciences at the University of Alabama, led this study to see if a drug could help prevent type 2 diabetes.

Type 2 diabetes is a disease in which a person has high blood sugar because the body does not properly respond to insulin, a hormone that regulates metabolism.

Type 2 diabetes can be partly managed with lifestyle interventions like a healthier diet and regular exercise. Sometimes people with type 2 diabetes also use medications to help manage their blood sugar.

People with prediabetes are at risk of developing type 2 diabetes, but do not have all of the symptoms yet. According to this study, 79 million Americans older than 20 have prediabetes. Past studies have shown that weight loss in overweight and obese patients can prevent prediabetes from progressing to type 2 diabetes.

This study looked at a combination medication that includes phentermine and topiramate, currently sold under the brand name Qysmia, to see if it would be helpful in preventing type 2 diabetes in people with prediabetes.

Phentermine and topiramate have both been used as weight loss medications independently. Phentermine (brand names Adipex-P, Ionamin and Suprenza) is used as an appetite suppressant and topiramate (brand name Topamax) is a medication that treats epilepsy.

To test the effectiveness of Qsymia in preventing prediabetes, the researchers identified 475 overweight or obese patients who had prediabetes and/or metabolic syndrome, a condition that also increases the risk of developing diabetes.

The participants were split into three groups: those who received a placebo (fake medicine), those who received a daily capsule of 7.5 milligrams of phentermine and 46 milligrams of topiramate and those who received a daily capsule of 15 milligrams of phentermine and 92 milligrams of topiramate. They took the medication for 108 weeks.

All of the participants also received counseling on living healthier during the last 52 weeks of the study.

The researchers periodically followed up with the patients to see if they had lost weight or been diagnosed with type 2 diabetes. They also checked the patients' blood sugar, blood pressure, cholesterol and waist size.

After the study concluded, the researchers found that the groups that had been treated with the medication lost significantly more weight than the comparison group. 

The group with the smaller dose lost 10.9 percent of their body weight, and the group with the larger dose lost 12.1 percent of their body weight. Those who had received the placebo lost 2.5 percent.

Additionally, the groups receiving the medication had significantly fewer cases of type 2 diabetes. A total of 6.1 percent of people in the placebo group developed diabetes, while only 1.8 and 1.3 percent were diagnosed in the lower and higher dose medication groups.

In other words, the groups taking the medication experienced a 71 percent (lower dose) and 79 percent (higher dose) reduction in type 2 diabetes risk than those taking a placebo.

The researchers also noted that regardless of the dose, greater weight loss led to a greater reduction in the risk of type 2 diabetes.

The medicine group also had improved heart health, blood sugar levels and waist size compared to the placebo group. 

However, the medication did have some side effects. More participants taking phentermine and topiramate reported tingling feelings, sinus infections, dry mouth and constipation than those taking a placebo. Also, some participants reported experiencing heart palpitations.

The researchers concluded that the combination drug including phentermine and topiramate was effective for patients with prediabetes and metabolic syndrome who wanted to lose weight and avoid type 2 diabetes. They also emphasized that risk reduction was greatly dependent on weight loss.

This study was published October 8 in Diabetes Care.

The authors did not disclose funding sources for the research. Some of the researchers reported conflicts of interest with pharmaceutical and weight loss companies.

Review Date: 
October 10, 2013
Last Updated:
October 13, 2013