Pioglitazone

12.1 Mechanism of Action Pioglitazone is a thiazolidinedione that depends on the presence of insulin for its mechanism of action. Pioglitazone decreases insulin resistance in the periphery and in the liver resulting in increased insulin-dependent glucose disposal and decreased hepatic glucose output. Pioglitazone is not an insulin secretagogue. Pioglitazone is an agonist for peroxisome proliferator-activated receptor-gamma (PPARγ). PPAR receptors are found in tissues important for insulin action such as adipose tissue, skeletal muscle, and liver. Activation of PPARγ nuclear receptors modulates the transcription of a number of insulin responsive genes involved in the control of glucose and lipid metabolism. In animal models of diabetes, pioglitazone reduces the hyperglycemia, hyperinsulinemia, and hypertriglyceridemia characteristic of insulin-resistant states such as type 2 diabetes. The metabolic changes produced by pioglitazone result in increased responsiveness of insulin- dependent tissues and are observed in numerous animal models of insulin resistance. Because pioglitazone enhances the effects of circulating insulin (by decreasing insulin resistance), it does not lower blood glucose in animal models that lack endogenous insulin.

1 INDICATIONS AND USAGE Monotherapy and Combination Therapy Pioglitazone tablets are indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus in multiple clinical settings [see Clinical Studies (14) ] . Important Limitations of Use Pioglitazone tablets exert its antihyperglycemic effect only in the presence of endogenous insulin. Pioglitazone tablets should not be used to treat type 1 diabetes or diabetic ketoacidosis, as it would not be effective in these settings. Use caution in patients with liver disease [see Warnings and Precautions (5.3) ] . Pioglitazone is a thiazolidinedione and an agonist for peroxisome proliferator-activated receptor (PPAR) gamma indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus in multiple clinical settings. ( 1, 14) Important Limitations of Use: Not for treatment of type 1 diabetes or diabetic ketoacidosis. ( 1 )

2 DOSAGE AND ADMINISTRATION Initiate pioglitazone tablets at 15 mg or 30 mg once daily. Limit initial dose to 15 mg once daily in patients with NYHA Class I or II heart failure. (2.1) If there is inadequate glycemic control, the dose can be increased in 15 mg increments up to a maximum of 45 mg once daily. (2.1) Obtain liver tests before starting pioglitazone tablets. If abnormal, use caution when treating with pioglitazone tablets, investigate the probable cause, treat (if possible) and follow appropriately. Monitoring liver tests while on pioglitazone tablets are not recommended in patients without liver disease. ( 5.3 ) 2.1 Recommendations for All Patients Pioglitazone tablets should be taken once daily and can be taken without regard to meals. The recommended starting dose for patients without congestive heart failure is 15 mg or 30 mg once daily. The recommended starting dose for patients with congestive heart failure (NYHA Class I or II) is 15 mg once daily. The dose can be titrated in increments of 15 mg up to a maximum of 45 mg once daily based on glycemic response as determined by HbA1c. After initiation of pioglitazone tablets or with dose increase, monitor patients carefully for adverse reactions related to fluid retention such as weight gain, edema, and signs and symptoms of congestive heart failure [see Boxed Warning and Warnings and Precautions (5.5) ] . Liver tests (serum alanine and aspartate aminotransferases, alkaline phosphatase, and total bilirubin) should be obtained prior to initiating pioglitazone tablets. Routine periodic monitoring of liver tests during treatment with pioglitazone tablets are not recommended in patients without liver disease. Patients who have liver test abnormalities prior to initiation of pioglitazone tablets or who are found to have abnormal liver tests while taking pioglitazone tablets should be managed as described under Warnings and Precautions [see Warnings and Precautions (5.3) and Clinical Pharmacology (12.3) ] . 2.2 Concomitant Use with an Insulin Secretagogue or Insulin If hypoglycemia occurs in a patient co-administered pioglitazone tablets and an insulin secretagogue (e.g., sulfonylurea), the dose of the insulin secretagogue should be reduced. If hypoglycemia occurs in a patient co-administered pioglitazone tablets and insulin, the dose of insulin should be decreased by 10% to 25%. Further adjustments to the insulin dose should be individualized based on glycemic response. 2.3 Concomitant Use with Strong CYP2C8 Inhibitors Coadministration of pioglitazone tablets and gemfibrozil, a strong CYP2C8 inhibitor, increases pioglitazone exposure approximately 3-fold. Therefore, the maximum recommended dose of pioglitazone tablets are 15 mg daily when used in combination with gemfibrozil or other strong CYP2C8 inhibitors [see Drug Interactions (7.1) and Clinical Pharmacology (12.3) ].

6 ADVERSE REACTIONS The following serious adverse reactions are discussed elsewhere in the labeling: Congestive heart failure [see Boxed Warning and Warnings and Precautions (5.1) ] Edema [see Warnings and Precautions (5.5) ] Fractures [see Warnings and Precautions (5.6) ] Most common adverse reactions (≥5%) are upper respiratory tract infection, headache, sinusitis, myalgia, and pharyngitis. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Quallent Pharmaceuticals Health LLC at 1-877-605-7243 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Over 8500 patients with type 2 diabetes have been treated with pioglitazone in randomized, double-blind, controlled clinical trials, including 2605 patients with type 2 diabetes and macrovascular disease treated with pioglitazone in the PROactive clinical trial. In these trials, over 6000 patients have been treated with pioglitazone for six months or longer, over 4500 patients have been treated with pioglitazone for one year or longer, and over 3000 patients have been treated with pioglitazone for at least two years. In six pooled 16- to 26-week placebo-controlled monotherapy and 16- to 24-week add-on combination therapy trials, the incidence of withdrawals due to adverse events was 4.5% for patients treated with pioglitazone and 5.8% for comparator-treated patients. The most common adverse events leading to withdrawal were related to inadequate glycemic control, although the incidence of these events was lower (1.5%) with pioglitazone than with placebo (3%). In the PROactive trial, the incidence of withdrawals due to adverse events was 9% for patients treated with pioglitazone and 7.7% for placebo-treated patients. Congestive heart failure was the most common serious adverse event leading to withdrawal occurring in 1.3% of patients treated with pioglitazone and 0.6% of patients treated with placebo. Common Adverse Events: 16- to 26-Week Monotherapy Trials A summary of the incidence and type of common adverse events reported in three pooled 16- to 26-week placebo-controlled monotherapy trials of pioglitazone is provided in Table 1. Terms that are reported represent those that occurred at an incidence of >5% and more commonly in patients treated with pioglitazone than in patients who received placebo. None of these adverse events were related to pioglitazone dose. Table 1. Three Pooled 16- to 26-Week Placebo-Controlled Clinical Trials of Pioglitazone Monotherapy: Adverse Events Reported at an Incidence > 5% and More Commonly in Patients Treated with Pioglitazone than in Patients Treated with Placebo % of Patients Placebo N=259 Pioglitazone N=606 Upper Respiratory Tract Infection 8.5 13.2 Headache 6.9 9.1 Sinusitis 4.6 6.3 Myalgia 2.7 5.4 Pharyngitis 0.8 5.1 Common Adverse Events: 16- to 24-Week Add-on Combination Therapy Trials A summary of the overall incidence and types of common adverse events reported in trials of pioglitazone add-on to sulfonylurea is provided in Table 2. Terms that are reported represent those that occurred at an incidence of >5% and more commonly with the highest tested dose of pioglitazone. Table 2. 16- to 24-Week Clinical Trials of Pioglitazone Add-on to Sulfonylurea Note: The preferred terms of edema peripheral, generalized edema, pitting edema and fluid retention were combined to form the aggregate term of “edema.” 16-Week Placebo-Controlled Trial Adverse Events Reported in > 5% of Patients and More Commonly in Patients Treated with Pioglitazone 30 mg + Sulfonylurea than in Patients Treated with Placebo + Sulfonylurea % of Patients Placebo + Sulfonylurea N=187 Pioglitazone 15 mg + Sulfonylurea N=184 Pioglitazone 30 mg + Sulfonylurea N=189 Edema 2.1 1.6 12.7 Headache 3.7 4.3 5.3 Flatulence 0.5 2.7 6.3 Weight Increased 0 2.7 5.3 24-Week Non-Controlled Double-Blind Trial Adverse Events Reported in > 5% of Patients and More Commonly in Patients Treated with Pioglitazone 45 mg + Sulfonylurea than in Patients Treated with Pioglitazone 30 mg + Sulfonylurea % of Patients Pioglitazone 30 mg + Sulfonylurea N=351 Pioglitazone 45 mg + Sulfonylurea N=351 Hypoglycemia 13.4 15.7 Edema 10.5 23.1 Upper Respiratory Tract Infection 12.3 14.8 Weight Increased 9.1 13.4 Urinary Tract Infection 5.7 6.8 A summary of the overall incidence and types of common adverse events reported in trials of pioglitazone add-on to metformin is provided in Table 3. Terms that are reported represent those that occurred at an incidence of >5% and more commonly with the highest tested dose of pioglitazone. Table 3. 16- to 24-Week Clinical Trials of Pioglitazone Add-on to Metformin Note: The preferred terms of edema peripheral, generalized edema, pitting edema and fluid retention were combin

7 DRUG INTERACTIONS Strong CYP2C8 inhibitors (e.g., gemfibrozil) increase pioglitazone concentrations. Limit pioglitazone dose to 15 mg daily. (2.3 , 7.1) CYP2C8 inducers (e.g., rifampin) may decrease pioglitazone concentrations. (7.2) Topiramate may decrease pioglitazone concentrations. ( 7.3 ) 7.1 Strong CYP2C8 Inhibitors An inhibitor of CYP2C8 (e.g., gemfibrozil) significantly increases the exposure (area under the serum concentration-time curve or AUC) and half-life (t 1/2 ) of pioglitazone. Therefore, the maximum recommended dose of pioglitazone is 15 mg daily if used in combination with gemfibrozil or other strong CYP2C8 inhibitors [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3) ]. 7.2 CYP2C8 Inducers An inducer of CYP2C8 (e.g., rifampin) may significantly decrease the exposure (AUC) of pioglitazone. Therefore, if an inducer of CYP2C8 is started or stopped during treatment with pioglitazone, changes in diabetes treatment may be needed based on clinical response without exceeding the maximum recommended daily dose of 45 mg for pioglitazone [see Clinical Pharmacology (12.3) ] . 7.3 Topiramate A decrease in the exposure of pioglitazone and its active metabolites were noted with concomitant administration of pioglitazone and topiramate [see Clinical Pharmacology (12.3) ] . The clinical relevance of this decrease is unknown; however, when pioglitazone and topiramate are used concomitantly, monitor patients for adequate glycemic control.