Pioglitazone

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 ] . 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. ( 14) Important Limitations of Use: • Not for treatment of type 1 diabetes or diabetic ketoacidosis. ()

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. • If there is inadequate glycemic control, the dose can be increased in 15 mg increments up to a maximum of 45 mg once daily. • 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. 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 ]. 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 and ] . 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 and ].

6 ADVERSE REACTIONS The following serious adverse reactions are discussed elsewhere in the labeling: • Congestive heart failure [see Boxed Warning and ] • Edema [see Warnings and Precautions ] • Fractures [see Warnings and Precautions ] Most common adverse reactions (≥5%) are upper respiratory tract infection, headache, sinusitis, myalgia, and pharyngitis. To report SUSPECTED ADVERSE REACTIONS, contact Rising Health, LLC at 1-833-395-6928 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 Pioglitazone Hydrochloride N = 259 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 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 Note: The preferred terms of edema peripheral, generalized edema, pitting edema and fluid retention were combined to form the aggregate term of “edema.” 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 16 Week Placebo-Controlled Trial Adverse Events Reported in > 5% of Patients and More Commonly in Patients Treated with Pioglitazone Hydrochloride + Metformin than in Patients Treated with Placebo + Metformin % of Patients Placebo + Metformin N = 160 Pioglitazone 30 mg + Metformin N = 168 Edema 2.5 6.0 Headache 1.9 6.0 24 Week Non-Controlled Double-Blind Trial Adverse Events Reported in > 5% of Patients and More Commonly in Patients Treated with Pioglitazone 45 mg + Metformin than in Patients Treated with Pioglitazone 30 mg + Metformin % of Patients Pioglitazone 30 mg + Metformin N = 411 Pioglitazone 45 mg + Metformin N = 416 Upper Respiratory Tract Infection 12.4 13.5 Edema 5.8 13.9 Headache 5.4 5.8 Weight Increased 2.9 6.7 Note: The preferred terms of edema peripheral, generalized edema, pitting edema and fluid retention were combined to form the aggregate term of “edema.” Table 4 summarizes the incidence and types of common adverse events reported in trials of pioglitazone add-on to insulin. Terms that are reported represent those that occurred at an incidence of >5% and more commonly with the highest tested dose of pioglitazone. Table 4. 16- to 24-Week Clinical Trials of Pioglitazone Add-on to Insulin 16 Week Placebo-Controlled Trial Adverse Events Reported in > 5% of Patients and More Commonly in Patients Treated with Pioglitazone 30 mg + Insulin than in Patients Treated with Placebo + Insulin % of Patients Placebo + Insulin N = 187 Pioglitazone 15 mg + Insulin N = 191 Pioglitazone 30 mg + Insulin N = 188 Hypoglycemia 4.8 7.9 15.4 Edema 7.0 12.6 17.6 Upper Respiratory Tract Infection 9.6 8.4 14.9 Headache 3.2 3.1 6.9 Weight Increased 0.5 5.2 6.4 Back Pain 4.3 2.1 5.3 Dizziness 3.7 2.6 5.3 Flatulence 1.6 3.7 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 + Insulin than in Patients Treated with Pioglitazone 30 mg + Insulin % of Patients Pioglitazone 30 mg + Insulin N = 345 Pioglitazone 45 mg + Insulin N = 345 Hypoglycemia 43.5 47.8 Edema 22.0 26.1 Weight Increased 7.2 13.9 Urinary Tract Infection 4.9 8.7 Diarrhea 5.5 5.8 Back Pain 3.8 6.4 Blood Creatine Phosphokinase Increased 4.6 5.5 Sinusitis 4.6 5.5 Hypertension 4.1 5.5 Note: The preferred terms of edema peripheral, generalized edema, pitting edema and fluid retention were combined to form the aggregate term of “edema.” A summary of the overall incidence and types of common adverse events reported in the PROactive trial is provided in Table 5. 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. Table 5. PROactive Trial: Incidence and Types of Adverse Events Reported in > 5% of Patients Treated with Pioglitazone and More Commonly than Placebo % of Patients Placebo N = 2633 Pioglitazone Hydrochloride N = 2605 Hypoglycemia 18.8 27.3 Edema 15.3 26.7 Cardiac Failure 6.1 8.1 Pain in Extremity 5.7 6.4 Back Pain 5.1 5.5 Chest Pain 5.0 5.1 Mean duration of patient follow-up was 34.5 months. Congestive Heart Failure A summary of the incidence of adverse events related to congestive heart failure is provided in Table 6 for the 16- to 24-week add-on to sulfonylurea trials, for the 16- to 24-week add-on to insulin trials, and for the 16- to 24-week add-on to metformin trials. None of the events were fatal. Table 6. Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) Patients Treated with Pioglitazone Hydrochloride or Placebo Added on to a Sulfonylurea Number (%) of Patients Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks) Placebo + Sulfonylurea N = 187 Pioglitazone 15 mg + Sulfonylurea N = 184 Pioglitazone 30 mg + Sulfonylurea N = 189 Pioglitazone 30 mg + Sulfonylurea N = 351 Pioglitazone 45 mg + Sulfonylurea N = 351 At least one congestive heart failure event 2 (1.1%) 0 0 1 (0.3%) 6 (1.7%) Hospitalized 2 (1.1%) 0 0 0 2 (0.6%) Patients Treated with Pioglitazone Hydrochloride or Placebo Added on to Insulin Number (%) of Patients Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks) Placebo + Insulin N = 187 Pioglitazone 15 mg + Insulin N = 191 Pioglitazone 30 mg + Insulin N = 188 Pioglitazone 30 mg + Insulin N = 345 Pioglitazone 45 mg + Insulin N = 345 At least one congestive heart failure event 0 2 (1.0%) 2 (1.1%) 3 (0.9%) 5 (1.4%) Hospitalized 0 2 (1.0%) 1 (0.5%) 1 (0.3%) 3 (0.9%) Patients Treated with Pioglitazone Hydrochloride or Placebo Added on to Metformin Number (%) of Patients Placebo-Controlled Trial (16 weeks) Non-Controlled Double-Blind Trial (24 weeks) Placebo + Metformin N = 160 Pioglitazone 30 mg + Metformin N = 168 Pioglitazone 30 mg + Metformin N = 411 Pioglitazone 45 mg + Metformin N = 416 At least one congestive heart failure event 0 1 (0.6%) 0 1 (0.2%) Hospitalized 0 1 (0.6%) 0 1 (0.2%) Patients with type 2 diabetes and NYHA class II or early class III congestive heart failure were randomized to receive 24 weeks of double-blind treatment with either pioglitazone at daily doses of 30 mg to 45 mg (n=262) or glyburide at daily doses of 10 mg to 15 mg (n=256). A summary of the incidence of adverse events related to congestive heart failure reported in this study is provided in Table 7. Table 7. Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) in Patients with NYHA Class II or III Congestive Heart Failure Treated with Pioglitazone or Glyburide Number (%) of Subjects Pioglitazone Hydrochloride N = 262 Glyburide N = 256 Death due to cardiovascular causes (adjudicated) 5 (1.9%) 6 (2.3%) Overnight hospitalization for worsening CHF (adjudicated) 26 (9.9%) 12 (4.7%) Emergency room visit for CHF (adjudicated) 4 (1.5%) 3 (1.2%) Patients experiencing CHF progression during study 35 (13.4%) 21 (8.2%) Congestive heart failure events leading to hospitalization that occurred during the PROactive trial are summarized in Table 8. Table 8. Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) in PROactive Trial Number (%) of Patients Placebo N = 2633 Pioglitazone Hydrochloride N = 2605 At least one hospitalized congestive heart failure event 108 (4.1%) 149 (5.7%) Fatal 22 (0.8%) 25 (1.0%) Hospitalized, nonfatal 86 (3.3%) 124 (4.7%) Cardiovascular Safety In the PROactive trial, 5238 patients with type 2 diabetes and a history of macrovascular disease were randomized to pioglitazone (N=2605), force-titrated up to 45 mg daily or placebo (N=2633) in addition to standard of care. Almost all patients (95%) were receiving cardiovascular medications (beta blockers, ACE inhibitors, angiotensin II receptor blockers, calcium channel blockers, nitrates, diuretics, aspirin, statins and fibrates). At baseline, patients had a mean age of 62 years, mean duration of diabetes of 9.5 years, and mean HbA1c of 8.1%. Mean duration of follow-up was 34.5 months. The primary objective of this trial was to examine the effect of pioglitazone on mortality and macrovascular morbidity in patients with type 2 diabetes mellitus who were at high risk for macrovascular events. The primary efficacy variable was the time to the first occurrence of any event in a cardiovascular composite endpoint that included all-cause mortality, nonfatal myocardial infarction (MI) including silent MI, stroke, acute coronary syndrome, cardiac intervention including coronary artery bypass grafting or percutaneous intervention, major leg amputation above the ankle, and bypass surgery or revascularization in the leg. A total of 514 (19.7%) patients treated with pioglitazone and 572 (21.7%) placebo-treated patients experienced at least one event from the primary composite endpoint (hazard ratio 0.9; 95% Confidence Interval: 0.8, 1.02; p=0.1). Although there was no statistically significant difference between pioglitazone and placebo for the three-year incidence of a first event within this composite, there was no increase in mortality or in total macrovascular events with pioglitazone. The number of first occurrences and total individual events contributing to the primary composite endpoint is shown in Table 9. Table 9. PROactive: Number of First and Total Events for Each Component within the Cardiovascular Composite Endpoint Cardiovascular Events Placebo N = 2633 Pioglitazone Hydrochloride N = 2605 First Events Total events First Events Total events n (%) n n (%) n Any event 572 (21.7) 900 514 (19.7) 803 All-cause mortality 122 (4.6) 186 110 (4.2) 177 Nonfatal myocardial infarction (MI) 118 (4.5) 157 105 (4.0) 131 Stroke 96 (3.6) 119 76 (2.9) 92 Acute coronary syndrome 63 (2.4) 78 42 (1.6) 65 Cardiac intervention (CABG/PCI) 101 (3.8) 240 101 (3.9) 195 Major leg amputation 15 (0.6) 28 9 (0.3) 28 Leg revascularization 57 (2.2) 92 71 (2.7) 115 CABG = coronary artery bypass grafting; PCI = percutaneous intervention Weight Gain Dose-related weight gain occurs when pioglitazone is used alone or in combination with other antidiabetic medications. The mechanism of weight gain is unclear but probably involves a combination of fluid retention and fat accumulation. Tables 10 and 11 summarize the changes in body weight with pioglitazone and placebo in the 16- to 26-week randomized, double-blind monotherapy and 16- to 24-week combination add-on therapy trials and in the PROactive trial. Table 10. Weight Changes (kg) from Baseline During Randomized, Double-Blind Clinical Trials Control Group (Placebo) Pioglitazone 15 mg Pioglitazone 30 mg Pioglitazone 45 mg Median (25 th /75 th percentile) Median (25 th /75 th percentile) Median (25 th /75 th percentile) Median (25 th /75 th percentile) Monotherapy (16 to 26 weeks) -1.4 (-2.7/0.0) N = 256 0.9 (-0.5/3.4) N = 79 1.0 (-0.9/3.4) N = 188 2.6 (0.2/5.4) N = 79 Combination Therapy (16 to 24 weeks) Sulfonylurea -0.5 (-1.8/0.7) N = 187 2.0 (0.2/3.2) N = 183 3.1 (1.1/5.4) N = 528 4.1 (1.8/7.3) N = 333 Metformin -1.4 (-3.2/0.3) N = 160 N/A 0.9 (-1.3/3.2) N = 567 1.8 (-0.9/5.0) N = 407 Insulin 0.2 (-1.4/1.4) N = 182 2.3 (0.5/4.3) N = 190 3.3 (0.9/6.3) N = 522 4.1 (1.4/6.8) N = 338 Table 11. Median Change in Body Weight in Patients Treated with Pioglitazone Versus Patients Treated with Placebo During the Double-Blind Treatment Period in the PROactive Trial Placebo Pioglitazone Hydrochloride Median (25 th /75 th percentile) Median (25 th /75 th percentile) Change from baseline to final visit (kg) -0.5 (-3.3, 2.0) N = 2581 +3.6 (0.0, 7.5) N = 2560 Note: Median exposure for both pioglitazone and Placebo was 2.7 years. Edema Edema induced from taking pioglitazone is reversible when pioglitazone is discontinued. The edema usually does not require hospitalization unless there is coexisting congestive heart failure. A summary of the frequency and types of edema adverse events occurring in clinical investigations of pioglitazone is provided in Table 12. Table 12. Adverse Events of Edema in Patients Treated with Pioglitazone Number (%) of Patients Placebo Pioglitazone 15 mg Pioglitazone 30 mg Pioglitazone 45 mg Monotherapy (16 to 26 weeks) 3 (1.2%) N = 259 2 (2.5%) N = 81 13 (4.7%) N = 275 11 (6.5%) N = 169 Combined Therapy (16 to 24 weeks) Sulfonylurea 4 (2.1%) N = 187 3 (1.6%) N = 184 61 (11.3%) N = 540 81 (23.1%) N = 351 Metformin 4 (2.5%) N = 160 N/A 34 (5.9%) N = 579 58 (13.9%) N = 416 Insulin 13 (7.0%) N = 187 24 (12.6%) N = 191 109 (20.5%) N = 533 90 (26.1%) N = 345 Note: The preferred terms of edema peripheral, generalized edema, pitting edema and fluid retention were combined to form the aggregate term of “edema.” Hepatic Effects There has been no evidence of induced hepatotoxicity with pioglitazone in the pioglitazone controlled clinical trial database to date. One randomized, double-blind 3-year trial comparing pioglitazone to glyburide as add-on to metformin and insulin therapy was specifically designed to evaluate the incidence of serum ALT elevation to greater than three times the upper limit of the reference range, measured every eight weeks for the first 48 weeks of the trial then every 12 weeks thereafter. A total of 3/1051 (0.3%) patients treated with pioglitazone and 9/1046 (0.9%) patients treated with glyburide developed ALT values greater than three times the upper limit of the reference range. None of the patients treated with pioglitazone in the pioglitazone controlled clinical trial database to date have had a serum ALT greater than three times the upper limit of the reference range and a corresponding total bilirubin greater than two times the upper limit of the reference range, a combination predictive of the potential for severe drug-induced liver injury. Hypoglycemia In the pioglitazone clinical trials, adverse events of hypoglycemia were reported based on clinical judgment of the investigators and did not require confirmation with fingerstick glucose testing. In the 16-week add-on to sulfonylurea trial, the incidence of reported hypoglycemia was 3.7% with pioglitazone 30 mg and 0.5% with placebo. In the 16-week add-on to insulin trial, the incidence of reported hypoglycemia was 7.9% with pioglitazone 15 mg, 15.4% with pioglitazone 30 mg, and 4.8% with placebo. The incidence of reported hypoglycemia was higher with pioglitazone 45 mg compared to pioglitazone 30 mg in both the 24-week add-on to sulfonylurea trial (15.7% vs. 13.4%) and in the 24-week add-on to insulin trial (47.8% vs. 43.5%). Three patients in these four trials were hospitalized due to hypoglycemia. All three patients were receiving pioglitazone 30 mg (0.9%) in the 24-week add-on to insulin trial. An additional 14 patients reported severe hypoglycemia (defined as causing considerable interference with patient’s usual activities) that did not require hospitalization. These patients were receiving pioglitazone 45 mg in combination with sulfonylurea (n=2) or pioglitazone 30 mg or 45 mg in combination with insulin (n=12). Urinary Bladder Tumors Tumors were observed in the urinary bladder of male rats in the two-year carcinogenicity study [see ]. During the three year PROactive clinical trial, 14 patients out of 2605 (0.54%) randomized to pioglitazone and 5 out of 2633 (0.19%) randomized to placebo were diagnosed with bladder cancer. After excluding patients in whom exposure to study drug was less than one year at the time of diagnosis of bladder cancer, there were 6 (0.23%) cases on pioglitazone and two (0.08%) cases on placebo. After completion of the trial, a large subset of patients was observed for up to 10 additional years, with little additional exposure to pioglitazone. During the 13 years of both PROactive and observational follow-up, the occurrence of bladder cancer did not differ between patients randomized to pioglitazone or placebo (HR =1; 95% CI: 0.59 to 1.72) [see ] . Laboratory Abnormalities Hematologic Effects Pioglitazone may cause decreases in hemoglobin and hematocrit. In placebo-controlled monotherapy trials, mean hemoglobin values declined by 2% to 4% in patients treated with pioglitazone compared with a mean change in hemoglobin of -1% to +1% in placebo-treated patients. These changes primarily occurred within the first 4 to 12 weeks of therapy and remained relatively constant thereafter. These changes may be related to increased plasma volume associated with pioglitazone therapy and are not likely to be associated with any clinically significant hematologic effects. Creatine Phosphokinase During protocol-specified measurement of serum creatine phosphokinase (CPK) in pioglitazone clinical trials, an isolated elevation in CPK to greater than 10 times the upper limit of the reference range was noted in nine (0.2%) patients treated with pioglitazone (values of 2150 to 11400 IU/L) and in no comparator-treated patients. Six of these nine patients continued to receive pioglitazone, two patients were noted to have the CPK elevation on the last day of dosing and one patient discontinued pioglitazone due to the elevation. These elevations resolved without any apparent clinical sequelae. The relationship of these events to pioglitazone therapy is unknown. 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of pioglitazone. Because these reactions are reported voluntarily from a population of uncertain size, it is generally not possible to reliably estimate their frequency or establish a causal relationship to drug exposure. • New onset or worsening diabetic macular edema with decreased visual acuity [see ] . • Fatal and nonfatal hepatic failure [see ] . Postmarketing reports of congestive heart failure have been reported in patients treated with pioglitazone, both with and without previously known heart disease and both with and without concomitant insulin administration. In postmarketing experience, there have been reports of unusually rapid increases in weight and increases in excess of that generally observed in clinical trials. Patients who experience such increases should be assessed for fluid accumulation and volume-related events such as excessive edema and congestive heart failure [see Boxed Warning and ] .

12.3 Pharmacokinetics Following once-daily administration of pioglitazone, steady-state serum concentrations of both pioglitazone and its major active metabolites, M-III (keto derivative of pioglitazone) and M-IV (hydroxyl derivative of pioglitazone), are achieved within seven days. At steady-state, M-III and M-IV reach serum concentrations equal to or greater than that of pioglitazone. At steady-state, in both healthy volunteers and patients with type 2 diabetes, pioglitazone comprises approximately 30% to 50% of the peak total pioglitazone serum concentrations (pioglitazone plus active metabolites) and 20% to 25% of the total AUC. C max , AUC, and trough serum concentrations (C min ) for pioglitazone and M-III and M-IV, increased proportionally with administered doses of 15 mg and 30 mg per day. Absorption Following oral administration of pioglitazone, T max of pioglitazone was within two hours. Food delays the T max to three to four hours but does not alter the extent of absorption (AUC). Distribution The mean apparent volume of distribution (Vd/F) of pioglitazone following single- dose administration is 0.63 ± 0.41 (mean ± SD) L/kg of body weight. Pioglitazone is extensively protein bound (> 99%) in human serum, principally to serum albumin. Pioglitazone also binds to other serum proteins, but with lower affinity. M-III and M-IV are also extensively bound (> 98%) to serum albumin. Metabolism Pioglitazone is extensively metabolized by hydroxylation and oxidation; the metabolites also partly convert to glucuronide or sulfate conjugates. Metabolites M-III and M-IV are the major circulating active metabolites in humans. In vitro data demonstrate that multiple CYP isoforms are involved in the metabolism of pioglitazone, which include CYP2C8 and, to a lesser degree, CYP3A4 with additional contributions from a variety of other isoforms including the mainly extrahepatic CYP1A1. In vivo study of pioglitazone in combination with gemfibrozil, a strong CYP2C8 inhibitor, showed that pioglitazone is a CYP2C8 substrate [see and Drug Interactions (7) ]. Urinary 6ß-hydroxycortisol/cortisol ratios measured in patients treated with pioglitazone showed that pioglitazone is not a strong CYP3A4 enzyme inducer. Excretion and Elimination Following oral administration, approximately 15% to 30% of the pioglitazone dose is recovered in the urine. Renal elimination of pioglitazone is negligible, and the drug is excreted primarily as metabolites and their conjugates. It is presumed that most of the oral dose is excreted into the bile either unchanged or as metabolites and eliminated in the feces. The mean serum half-life (t1/2) of pioglitazone and its metabolites (M-III and M-IV) range from three to seven hours and 16 to 24 hours, respectively. Pioglitazone has an apparent clearance, CL/F, calculated to be five to seven L/hr. Renal Impairment The serum elimination half-life of pioglitazone, M-III, and M-IV remains unchanged in patients with moderate (creatinine clearance [CLcr] 30 to 50 mL/min) and severe (CLcr< 30 mL/min) renal impairment when compared to subjects with normal renal function. Therefore, no dose adjustment in patients with renal impairment is required. Hepatic Impairment Compared with healthy controls, subjects with impaired hepatic function (Child-Turcotte-Pugh Grade B/C) have an approximate 45% reduction in pioglitazone and total pioglitazone (pioglitazone, M-III, and M-IV) mean Cmax but no change in the mean AUC values. Therefore, no dose adjustment in patients with hepatic impairment is required. There are postmarketing reports of liver failure with pioglitazone and clinical trials have generally excluded patients with serum ALT >2.5 times the upper limit of the reference range. Use caution in patients with liver disease [see ]. Geriatric Patients In healthy elderly subjects, Cmax of pioglitazone was not significantly different, but AUC values were approximately 21% higher than those achieved in younger subjects. The mean t1/2 of pioglitazone was also prolonged in elderly subjects (about ten hours) as compared to younger subjects (about seven hours). These changes were not of a magnitude that would be considered clinically relevant. Pediatric Patients Safety and efficacy of pioglitazone in pediatric patients have not been established. Pioglitazone is not recommended for use in pediatric patients [see ] . Gender The mean C max and AUC values of pioglitazone were increased 20% to 60% in women compared to men. In controlled clinical trials, HbA1c decreases from baseline were generally greater for females than for males (average mean difference in HbA1c 0.5%). Because therapy should be individualized for each patient to achieve glycemic control, no dose adjustment is recommended based on gender alone. Ethnicity Pharmacokinetic data among various ethnic groups are not available. Drug-Drug Interactions Table 14. Effect of Pioglitazone Coadministration on Systemic Exposure of Other Drugs Coadministered Drug Pioglitazone Dosage Regimen (mg) Name and Dose Regimens Change in AUC Change in C max 45 mg (N = 12) Warfarin Daily loading then maintenance doses based PT and INR values Quick's Value = 35 ± 5% R-Warfarin ↓ 3% R-Warfarin ↓ 2% S-Warfarin ↓ 1% S-Warfarin ↑ 1% 45 mg (N = 12) Digoxin 0.200 mg twice daily (loading dose) then 0.250 mg daily (maintenance dose, 7 days) ↑ 15% ↑ 17% 45 mg daily for 21 days (N = 35) Oral Contraceptive [Ethinyl Estradiol (EE) 0.035 mg plus Norethindrone (NE) 1 mg] for 21 days EE ↓ 11% EE ↓ 13% NE ↑ 3% NE ↓ 7% 45 mg (N = 23) Fexofenadine 60 mg twice daily for 7 days ↑ 30% ↑ 37% 45 mg (N = 14) Glipizide 5 mg daily for 7 days ↓ 3% ↓ 8% 45 mg daily for 8 days (N = 16) Metformin 1000 mg single dose on Day 8 ↓ 3% ↓ 5% 45 mg (N = 21) Midazolam 7.5 mg single dose on Day 15 ↓ 26% ↓ 26% 45 mg (N = 24) Ranitidine 150 mg twice daily for 7 days ↑ 1% ↓ 1% 45 mg daily for 4 days (N = 24) Nifedipine ER 30 mg daily for 4 days ↓ 13% ↓ 17% 45 mg (N = 25) Atorvastatin Ca 80 mg daily for 7 days ↓ 14% ↓ 23% 45 mg (N = 22) Theophylline 400 mg twice daily for 7 days ↑ 2% ↑ 5% * Daily for 7 days unless otherwise noted. † % change (with/without coadministered drug and no change = 0%); symbols of ↑ and ↓ indicate the exposure increase and decrease, respectively. ‡ Pioglitazone had no clinically significant effect on prothrombin time. Table 15. Effect of Coadministered Drugs on Pioglitazone Systemic Exposure Placebo Pioglitazone 15 mg Once Daily Pioglitazone 30 mg Once Daily Pioglitazone 45 mg Once Daily Total Population HbA1c (%) N = 79 N = 79 N = 85 N = 76 Baseline (mean) 10.4 10.2 10.2 10.3 Change from baseline (adjusted mean) 0.7 -0.3 -0.3 -0.9 Difference from placebo (adjusted mean) 95% Confidence Interval -1.0 (-1.6, -0.4) -1.0 (-1.6, -0.4) -1.6 (-2.2, -1.0) Fasting Plasma Glucose (mg/dL) N = 79 N = 79 N = 84 N = 77 Baseline (mean) 268 267 269 276 Change from baseline (adjusted mean) 9 -30 -32 -56 Difference from placebo (adjusted mean) 95% Confidence Interval -39 (-63, -16) -41 (-64, -18) -65 (-89, -42) 1 Daily for 7 days unless otherwise noted. 2 Mean ratio (with/without coadministered drug and no change = 1-fold) % change (with/without coadministered drug and no change = 0%); symbols of ↑ and ↓ indicate the exposure increase and decrease, respectively. ‡ The half-life of pioglitazone increased from 8.3 hours to 22.7 hours in the presence of gemfibrozil [see and ] § Indicates duration of concomitant administration with highest twice-daily dose of topiramate from Day 14 onwards over the 22 days of study ¶ Additional decrease in active metabolites; 60% for M-III and 16% for M-IV