Thiazolidinediones (glitazones: rosiglitazone and pioglitazone)
Thiazolidinediones (TZDs) work to lower your blood sugar by increasing the muscle, fat and liver’s sensitivity to insulin. TZDs are referred to as “insulin sensitizers” and also are blood sugar normalizing or euglycemics, (drugs that help return the blood sugar to the normal range without the risk of low blood sugars.) TZDs take a while to begin working (several weeks); so don’t stop the pill if you don’t notice your blood sugar responding right away.
The main side effects are weight gain and fluid retention (you may notice your ankles swelling) and anemia. Fluid retention is most common in individuals who are also taking insulin secretagogues and insulin, and has been linked with an increased rate of congestive heart failure. Thiazolidinediones increase the amount of certain fat particles, called LDL. Women taking these medications have a greater chance of bone fractures.
One of the thiazolidinediones, rosiglitazone, Avandia®, is reported to increase heart disease. The United States FDA has limited the use of this medication to those individuals already using it, and to those who have failed therapy with other medications, or who decline to take pioglitazone. Some European countries ( Germany and France) have withdrawn pioglitizone, Actos®, because of concern about an increased risk of bladder cancer.
You shouldn’t take a thizolidinedione if you have congestive heart failure, or significant liver or kidney problems. If you are female or have an increased risk of heart disease, discuss with you provider whether these are appropriate medications for you
In short, thiazolidinediones decrease insulin resistance.
The most common side effects are:
- Fluid retention
- Weight gain
- Increased LDL
- Congestive heart failure
- Increase risk of heart disease (Avandia®)
- Increased bone fractures in women
For more information about Glitazone pill strength (formulations), initial and final doses, side effects, and different Glitazone containing preparations on the market, see our Medication Table.
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