Definition: A thiazolidinedione (TZD) is a type 2 diabetes pill that makes the body more sensitive to its own insulin. MedlinePlus puts pioglitazone in this class. In the US it is sold as Actos and in the combination pills Actoplus Met, Duetact and Oseni. The Actos label says it works only when the body still makes insulin.
Actos has a boxed warning: thiazolidinediones cause or worsen congestive heart failure in some people. After starting and after dose increases, people are watched for fast weight gain, shortness of breath or swelling. Starting it with NYHA Class III or IV heart failure is contraindicated. Insulin labels repeat the point: a TZD taken with insulin can cause fluid retention that may lead to or worsen heart failure.
| Group | Placebo | 15 mg | 30 mg | 45 mg |
|---|---|---|---|---|
| Actos alone | 1.2% | 2.5% | 4.7% | 6.5% |
| Actos with insulin | 7.0% | 12.6% | 20.5% | 26.1% |
Median weight on Actos alone rose 0.9 to 2.6 kg by dose, against a 1.4 kg loss on placebo. In the PROactive trial, bone fractures in women were 5.1% against 2.5% on placebo. The label also notes it may cause ovulation in some premenopausal women who do not ovulate.
Weight and swelling are what the label says to watch. Logging weight on the same scale at the same time of day after starting or changing the dose makes a fast rise easy to see.
Read more on Dose Track: Pioglitazone guide · Actos side effects · Actoplus Met side effects · Duetact side effects