The pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage and administration of
troglitazone are reviewed.
Troglitazone is the first oral
thiazolidinedione approved for use in treating
non-insulin-dependent diabetes mellitus (
NIDDM). The
drug's mechanism of action has not been fully elucidated.
Troglitazone acts as an
insulin sensitizer. Cell-line and animal models indicate that
troglitazone may decrease hepatic
glucose output by decreasing the rate of gluconeogenesis in the liver or by increasing glycolysis.
Troglitazone is rapidly absorbed after
oral administration, with peak concentration occurring in two to three hours. Food increases absorption by 30-85%. The
drug is extensively metabolized in the liver.
Troglitazone has been shown to be efficacious in treating
NIDDM, both as monotherapy and in combination with oral sulfonylureas. Patients who are obese or who have high fasting plasma
insulin levels may derive the greatest benefit. Patients with
impaired glucose tolerance, syndrome X,
polycystic ovary syndrome,
gestational diabetes, or
Werner's syndrome may also benefit from
troglitazone. Adverse effects, including hematologic abnormalities, liver toxicity, and
hypoglycemia, have been rare in published trials; no life-threatening effects have been reported thus far. The recommended initial dosage is 200 mg once daily with meals, with an increase to 400 mg daily if satisfactory
glycemic control is not achieved after two to four weeks. The average wholesale price is $348 for 100 200-mg
tablets and $534 for 100 400-mg
tablets.
Troglitazone may be an effective agent for treating
NIDDM, especially in patients who are obese or who have high fasting plasma
insulin levels.