Combination Therapy for Diabetes
Weighing the Pros and Cons of Drug Combinations continued...
Body weight is another issue doctors consider in choosing a combination diabetes therapy. Many people with type 2 diabetes are overweight or obese. Excess body weight worsens blood sugar control. Unfortunately, some oral agents, such as Actos and Avandia, tend to cause weight gain. Insulin also tends to promote weight gain.
“Since being weight increases diabetes risk and poses other health problems, we want to try to choose medications that help people maintain a healthy weight whenever possible,” says Einhorn. The first choice for oral diabetes medication is typically metformin, which does not promote weight gain. In overweight or obese patients, it is often paired with a GLP-1 agonist. These new agents have been shown to suppress appetite and increase satiety, helping roughly 30% of patients on them to lose modest amounts of weight.
Almost all drugs have unwanted side effects in some people, of course. Metformin can cause nausea, abdominal pain, and diarrhea in a very small percentage of patients. GLP-1 agonists can also cause gastrointestinal side effects. “We do have a small percentage of patients who go off them because they just can’t tolerate the side effects,” says Marina Basina, MD, clinical assistant professor of medicine in the division of endocrinology at Stanford University in Stanford, Calif. “But most patients do well on them.”
Patients who can’t tolerate GLP-1 agonists may fare better on another new injectable diabetes drug, called pramlintide (Symlin). A synthetic form of a naturally occurring hormone that helps the body maintain normal blood sugar levels, pramlintide is approved for use when insulin alone does not adequately lower blood glucose levels.
A Matter of Trial and Error
Choosing the best diabetes therapies is as much an art as a science. The American Diabetes Association publishes annual treatment guidelines. Leading professional groups also release recommendations. “But the field of diabetes treatment is changing so fast that some guidelines may be out-of-date almost as soon as they’re published,” says Maratos-Flier. “The only way to find the best therapeutic regimen is through trial and error. There’s almost no way to know in advance how patients will respond to a given medication or combination of medications.”
What’s more, drug regimens must be tailored to the individual patient. “There is no single best combination for all patients,” says Basina. “And over time, we often have to change the regimen if patients stop responding to a certain drug or develop side effects.”
To make sure your diabetes medication regimen is working adequately, it’s important to monitor blood sugar levels. How often you test blood sugar levels will depend on the medications you’re taking and how well your blood sugar levels are controlled.
“The sooner you bring blood sugar levels down to normal, and the better control you have over time, the less likely your diabetes is to progress,” says Einhorn.