definition of Actos (pioglitazone hydrochloride): Actos® is usually prescribed for treatment of diabetes. Pioglitazone works by decreasing insulin resistance, and increasing sensitivity to insulin in muscle and fat tissue. Pioglitazone has also been shown to be anti-inflammatory in some conditions. Pioglitazone is being tested in people with neurological disorders, including autism, because it can also be anti-inflammatory in glial cells in the brain. Preliminary studies showed improvements in behavior in children with autism.