Overview
Pioglitazone is a thiazolidinedione antidiabetic agent used as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. It works by improving insulin sensitivity in peripheral tissues and reducing hepatic glucose production. The drug is not effective for type 1 diabetes or diabetic ketoacidosis.
Mechanism of Action
Pioglitazone is a peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist that enhances cellular responsiveness to insulin, increases insulin-dependent glucose disposal, and improves hepatic sensitivity to insulin. This results in decreased insulin resistance, lower plasma glucose concentrations, and improved glycemic control.
Indications
- Adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus
- Can be used as monotherapy or in combination with other antidiabetic agents such as sulfonylureas, metformin, or insulin
Common Doses
- 15 mg
- 30 mg
- 45 mg
Dosage
Initial dose typically 15-30 mg once daily, may be increased to maximum 45 mg once daily based on glycemic response. Should be taken with or without food.
Black Box Warning
Boxed warning: May cause or exacerbate congestive heart failure
Contraindications
- Initiation in patients with established NYHA Class III or IV heart failure
- Known hypersensitivity to pioglitazone or any component of the formulation
Side Effects
- Edema and fluid retention
- Congestive heart failure
- Fractures (especially in women)
- Upper respiratory tract infection
- Headache
- Weight gain
- Hypoglycemia when used with other antidiabetic agents
Interactions
- Strong CYP2C8 inhibitors may increase pioglitazone concentrations
- Gemfibrozil significantly increases pioglitazone exposure
- Rifampin decreases pioglitazone concentrations
- May enhance hypoglycemic effects when combined with other antidiabetic agents
Counseling Points
- Take once daily with or without food
- Report any symptoms of heart failure (shortness of breath, swelling, rapid weight gain)
- Monitor blood glucose regularly as directed
- Be aware of increased fracture risk, especially for female patients
- Report any signs of liver problems (nausea, vomiting, abdominal pain, fatigue, dark urine, jaundice)
- Understand that improvement in glycemic control may take several weeks