Source: FDA, National Drug Code (US) Revision Year: 2019
Pioglitazone, like other thiazolidinediones, can cause dose-related fluid retention when used alone or in combination with other antidiabetic medications and is most common when pioglitazone is used in combination with insulin. Fluid retention may lead to or exacerbate congestive heart failure. Patients treated with ACTOPLUS MET XR should be observed for signs and symptoms of congestive heart failure. If congestive heart failure develops, it should be managed according to current standards of care and discontinuation or dose reduction of ACTOPLUS MET XR must be considered [see Boxed Warning, Contraindications (4), and Adverse Reactions (6.1)].
There have been post-marketing cases of metformin-associated lactic acidosis, including fatal cases. These cases had a subtle onset and were accompanied by nonspecific symptoms such as malaise, myalgias, abdominal pain, respiratory distress, or increased somnolence; however, hypothermia, hypotension and resistant bradyarrhythmias have occurred with severe acidosis. Metformin-associated lactic acidosis was characterized by elevated blood lactate concentrations (greater than 5 mmol/Liter), anion gap acidosis (without evidence of ketonuria or ketonemia), and an increased lactate:pyruvate ratio; metformin plasma levels generally greater than 5 mcg/mL. Metformin decreases liver uptake of lactate increasing lactate blood levels which may increase the risk of lactic acidosis, especially in patients at risk.
If metformin-associated lactic acidosis is suspected, general supportive measures should be instituted promptly in a hospital setting, along with immediate discontinuation of ACTOPLUS MET XR. Patients treated with ACTOPLUS MET XR with a diagnosis or strong suspicion of lactic acidosis, prompt hemodialysis is recommended to correct the acidosis and remove accumulated metformin (metformin hydrochloride is dialyzable, with a clearance of up to 170 mL/min under good hemodynamic conditions). Hemodialysis has often resulted in reversal of symptoms and recovery.
Educate patients and their families about the symptoms of lactic acidosis and if these symptoms occur instruct them to discontinue ACTOPLUS MET XR and report these symptoms to their healthcare provider.
For each of the known and possible risk factors for metformin-associated lactic acidosis, recommendations to reduce the risk of and manage metformin-associated lactic acidosis are provided below:
The postmarketing metformin-associated lactic acidosis cases primarily occurred in patients with significant renal impairment. The risk of metformin accumulation and metformin-associated lactic acidosis increases with the severity of renal impairment because metformin is substantially excreted by the kidney. Clinical recommendations based upon the patient’s renal function include [see Dosage and Administration (2.2), Clinical Pharmacology (12.3)].
The concomitant use of ACTOPLUS MET XR with specific drugs may increase the risk of metformin-associated lactic acidosis: those that impair renal function, result in significant hemodynamic change, interfere with acid-base balance or increase metformin accumulation (e.g., cationic drugs) [see Drug Interactions (7)]. Therefore, consider more frequent monitoring of patients.
The risk of metformin-associated lactic acidosis increases with the patient’s age because elderly patients have a greater likelihood of having hepatic, renal, or cardiac impairment than younger patients. Assess renal function more frequently in elderly patients [see Use in Specific Populations (8.5)].
Administration of intravascular iodinated contrast agents in patients treated with metformin has led to an acute decrease in renal function and the occurrence of lactic acidosis. Stop ACTOPLUS MET XR at the time of, or prior to, an iodinated contrast imaging procedure in patients with an eGFR between 30 and 60 mL/min/1.73 m2; in patients with a history of hepatic impairment, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Re-evaluate eGFR 48 hours after the imaging procedure, and restart ACTOPLUS MET XR if renal function is stable.
Withholding of food and fluids during surgical or other procedures may increase the risk for volume depletion, hypotension and renal impairment. ACTOPLUS MET XR should be temporarily discontinued while patients have restricted food and fluid intake.
Several of the postmarketing cases of metformin-associated lactic acidosis occurred in the setting of acute congestive heart failure (particularly when accompanied by hypoperfusion and hypoxemia). Cardiovascular collapse (shock), acute myocardial infarction, sepsis, and other conditions associated with hypoxemia have been associated with lactic acidosis and may also cause prerenal azotemia. When such events occur, discontinue ACTOPLUS MET XR.
Alcohol potentiates the effect of metformin on lactate metabolism and this may increase the risk of metformin-associated lactic acidosis. Warn patients against excessive alcohol intake while receiving ACTOPLUS MET XR.
Patients with hepatic impairment have developed with cases of metformin-associated lactic acidosis. This may be due to impaired lactate clearance resulting in higher lactate blood levels. Therefore, avoid use of ACTOPLUS MET XR in patients with clinical or laboratory evidence of hepatic disease.
In controlled clinical trials with pioglitazone, edema was reported more frequently in patients treated with pioglitazone than in patients treated with placebo and is dose related [see Adverse Reactions (6.1)]. In postmarketing experience, reports of new onset or worsening of edema have been received. ACTOPLUS MET XR should be used with caution in patients with edema. Because thiazolidinediones, including pioglitazone, can cause fluid retention, which can exacerbate or lead to congestive heart failure, ACTOPLUS MET XR should be used with caution in patients at risk for congestive heart failure. Patients treated with ACTOPLUS MET XR should be monitored for signs and symptoms of congestive heart failure [see Boxed Warning, Warnings and Precautions (5.1) and Patient Counseling Information (17)].
Patients receiving ACTOPLUS MET XR in combination with insulin or other anti-diabetic medications (particularly insulin secretagogues such as sulfonylureas) may be at risk for hypoglycemia. A reduction in the dose of the concomitant anti-diabetic medication may be necessary to reduce the risk of hypoglycemia [see Drug Interactions (7.7)]. Hypoglycemia can also occur when caloric intake is deficient or when strenuous exercise is not compensated by caloric supplement. Elderly, debilitated, or malnourished patients and those with adrenal or pituitary insufficiency or alcohol intoxication are particularly susceptible to hypoglycemic effects. Hypoglycemia may be difficult to recognize in the elderly, and in people who are taking beta-adrenergic blocking drugs.
There have been postmarketing reports of fatal and non-fatal hepatic failure in patients taking pioglitazone, although the reports contain insufficient information necessary to establish the probable cause. There has been no evidence of drug-induced hepatotoxicity in the pioglitazone controlled clinical trial database to date [see Adverse Reactions (6.1)].
Patients with type 2 diabetes may have fatty liver disease or cardiac disease with episodic congestive heart failure, both of which may cause liver test abnormalities, and they may also have other forms of liver disease, many of which can be treated or managed. Therefore, obtaining a liver test panel (serum alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase, and total bilirubin) and assessing the patient is recommended before initiating ACTOPLUS MET XR therapy.
In patients with abnormal liver tests, ACTOPLUS MET XR should be initiated with caution.
Measure liver tests promptly in patients who report symptoms that may indicate liver injury, including fatigue, anorexia, right upper abdominal discomfort, dark urine or jaundice. In this clinical context, if the patient is found to have abnormal liver tests (ALT greater than three times the upper limit of the reference range), ACTOPLUS MET XR treatment should be interrupted and investigation done to establish the probable cause. ACTOPLUS MET XR should not be restarted in these patients without another explanation for the liver test abnormalities.
Patients who have serum ALT greater than three times the reference range with serum total bilirubin greater than two times the reference range without alternative etiologies are at risk for severe drug-induced liver injury, and should not be restarted on ACTOPLUS MET XR. For patients with lesser elevations of serum ALT or bilirubin and with an alternate probable cause, treatment with ACTOPLUS MET XR can be used with caution.
Tumors were observed in the urinary bladder of male rats in the two-year carcinogenicity study [see Nonclinical Toxicology (13.1)]. In addition, 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=1.00; [95% CI: 0.59–1.72]).
Findings regarding the risk of bladder cancer in patients exposed to pioglitazone vary among observational studies; some did not find an increased risk of bladder cancer associated with pioglitazone, while others did.
A large prospective 10-year observational cohort study conducted in the United States found no statistically significant increase in the risk of bladder cancer in diabetic patients ever exposed to pioglitazone, compared to those never exposed to pioglitazone (HR=1.06 [95% CI 0.89–1.26]).
A retrospective cohort study conducted with data from the United Kingdom found a statistically significant association between ever exposure to pioglitazone and bladder cancer (HR: 1.63; [95% CI: 1.22–2.19]).
Associations between cumulative dose or cumulative duration of exposure to pioglitazone and bladder cancer were not detected in some studies including the 10-year observational study in the U.S., but were in others. Inconsistent findings and limitations inherent in these and other studies preclude conclusive interpretations of the observational data.
Pioglitazone may be associated with an increase in the risk of urinary bladder tumors. There are insufficient data to determine whether pioglitazone is a tumor promoter for urinary bladder tumors.
Consequently, ACTOPLUS MET XR should not be used in patients with active bladder cancer and the benefits of glycemic control versus unknown risks for cancer recurrence with ACTOPLUS MET XR should be considered in patients with a prior history of bladder cancer.
In PROactive (the Prospective Pioglitazone Clinical Trial in Macrovascular Events), 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. During a mean follow-up of 34.5 months, the incidence of bone fracture in females was 5.1% (44/870) for pioglitazone versus 2.5% (23/905) for placebo. This difference was noted after the first year of treatment and persisted during the course of the study. The majority of fractures observed in female patients were nonvertebral fractures including lower limb and distal upper limb. No increase in the incidence of fracture was observed in men treated with pioglitazone (1.7%) versus placebo (2.1%). The risk of fracture should be considered in the care of patients, especially female patients, treated with ACTOPLUS MET XR and attention should be given to assessing and maintaining bone health according to current standards of care.
Macular edema has been reported in postmarketing experience in diabetic patients who were taking pioglitazone or another thiazolidinedione. Some patients presented with blurred vision or decreased visual acuity, but others were diagnosed on routine ophthalmologic examination.
Most patients had peripheral edema at the time macular edema was diagnosed. Some patients had improvement in their macular edema after discontinuation of the thiazolidinedione.
Patients with diabetes should have regular eye exams by an ophthalmologist according to current standards of care. Patients with diabetes who report any visual symptoms should be promptly referred to an ophthalmologist, regardless of the patient’s underlying medications or other physical findings [see Adverse Reactions (6.1)].
In controlled clinical trials of metformin of 29 weeks duration, a decrease to subnormal levels of previously normal serum vitamin B12 levels, without clinical manifestations, was observed in approximately 7% of patients. Such decrease, possibly due to interference with B12 absorption from the B12intrinsic factor complex, is, however, very rarely associated with anemia and appears to be rapidly reversible with discontinuation of metformin or vitamin B12 supplementation. Measurement of hematologic parameters on an annual basis is advised in patients on ACTOPLUS MET XR and any apparent abnormalities should be appropriately investigated and managed. Certain individuals (those with inadequate vitamin B12 or calcium intake or absorption) appear to be predisposed to developing subnormal vitamin B12 levels. In these patients, routine serum vitamin B12 measurements at two to three-year intervals may be useful.
There have been no clinical studies establishing conclusive evidence of macrovascular risk reduction with ACTOPLUS MET XR.
The following serious adverse reactions are discussed elsewhere in the labeling:
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 from the PROactive clinical trial. In these trials, over 6000 patients have been treated with pioglitazone for 6 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 patients treated with comparator. 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 (3.0%).
In the PROactive trial, the incidence of withdrawals due to adverse events was 9.0% for patients treated with pioglitazone and 7.7% for patients treated with placebo. 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.
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 the 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 |
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 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 Metformin:
| 16-Week Placebo-Controlled Trial Adverse Events Reported in >5% of Patients and More Commonly in Patients Treated with Pioglitazone + 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”.
A summary of the overall incidence and types of common adverse events reported in the PROactive trial is provided in Table 3. 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 3. 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 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.
A summary of the incidence of adverse events related to congestive heart failure is provided in Table 4 for the 16- to 24-week add-on to metformin trials. None of the events were fatal.
Table 4. Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) Patients Treated with Pioglitazone 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%) |
Table 5. Treatment–Emergent Adverse Events of Congestive Heart Failure (CHF):
| Patients Treated with Pioglitazone 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 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 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%) | |
Table 6. 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 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 7.
Table 7. Treatment-Emergent Adverse Events of Congestive Heart Failure (CHF) in PROactive Trial:
| Number (%) of Patients | ||
|---|---|---|
| Placebo N=2633 | Pioglitazone N=2605 | |
| At least one hospitalized congestive heart failure event | 108 (4.1%) | 149 (5.7%) |
| Fatal | 22 (0.8%) | 25 (1%) |
| Hospitalized, non-fatal | 86 (3.3%) | 124 (4.7%) |
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, non-fatal 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%) patients treated with placebo experienced at least one event from the primary composite endpoint (hazard ratio 0.90; 95% Confidence Interval: 0.80, 1.02; p=0.10).
Although there was no statistically significant difference between pioglitazone and placebo for the 3-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 8.
Table 8. PROactive: Number of First and Total Events for Each Component within the Cardiovascular Composite Endpoint:
| Cardiovascular Events | Placebo N=2633 | Pioglitazone N=2605 | |||
|---|---|---|---|---|---|
| First Events n (%) | Total Events n | First Events n (%) | Total Events n | ||
| Any event | 572 (21.7) | 900 | 514 (19.7) | 803 | |
| All-cause mortality | 122 (4.6) | 186 | 110 (4.2) | 177 | |
| Non-fatal 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
Dose-related weight gain occurs when pioglitazone is used alone or in combination with other anti-diabetic medications. The mechanism of weight gain is unclear but probably involves a combination of fluid retention and fat accumulation.
Tables 9 and 10 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 9. Weight Changes (kg) from Baseline during Randomized, Double-Blind Clinical Trials:
| Control Group (Placebo) | Pioglitazone 15 mg | Pioglitazone 30 mg | Pioglitazone 45 mg | ||
|---|---|---|---|---|---|
| Median (25th/75th percentile) | Median (25th/75th percentile) | Median (25th/75th percentile) | Median (25th/75th 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 10. 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 | |
|---|---|---|
| Median (25th, 75th percentile) | Median (25th, 75th 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 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 11.
Table 11. 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”.
Table 12. Adverse Events of Edema in Patients in the PROactive Trial:
| Number (%) of Patients | |
|---|---|
| Placebo N=2633 | Pioglitazone N=2605 |
| 419 (15.9%) | 712 (27.3%) |
Note: The preferred terms of edema peripheral, generalized edema, pitting edema and fluid retention were combined to form the aggregate term of “edema”.
There has been no evidence of pioglitazone-induced hepatotoxicity 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 8 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 >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 >three times the upper limit of the reference range and a corresponding total bilirubin >two times the upper limit of the reference range, a combination predictive of the potential for severe drug-induced liver injury.
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).
Tumors were observed in the urinary bladder of male rats in the two-year carcinogenicity study [see Nonclinical Toxicology (13.1)]. 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 =1.00; 95% CI: 0.59-1.72) [see Warnings and Precautions (5.6)].
In a double-blind clinical study of metformin in patients with type 2 diabetes, a total of 141 patients received metformin therapy (up to 2550 mg per day) and 145 patients received placebo. Adverse reactions reported in greater than 5% of the metformin patients, and that were more common in metformin than patients treated with placebo, are listed in Table 13. In this trial, diarrhea led to discontinuation of study medication in 6% of patients treated with metformin.
Table 13. Most Common Adverse Reactions (>5.0%) in a Placebo-Controlled Clinical Study of Metformin Monotherapy*:
| Adverse Reaction | Metformin Monotherapy (n=141) | Placebo (n=145) |
|---|---|---|
| % of Patients | ||
| Diarrhea | 53.2 | 11.7 |
| Nausea/Vomiting | 25.5 | 8.3 |
| Flatulence | 12.1 | 5.5 |
| Asthenia | 9.2 | 5.5 |
| Indigestion | 7.1 | 4.1 |
| Abdominal Discomfort | 6.4 | 4.8 |
| Headache | 5.7 | 4.8 |
* Reactions that were more common in metformin than patients treated with placebo.
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 patients treated with placebo. These changes primarily occurred within the first four 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.
Metformin may lower serum vitamin B12 concentrations. Measurement of hematologic parameters on an annual basis is advised in patients on ACTOPLUS MET XR and any apparent abnormalities should be appropriately investigated and managed [see Warnings and Precautions (5.9)].
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 9 (0.2%) patients treated with pioglitazone (values of 2150 to 11400 IU/L) and in no patients treated with comparator. 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.
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.
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 Warnings and Precautions (5.1)].
Cholestatic, hepatocellular, and mixed hepatocellular liver injury.
An inhibitor of CYP2C8 (e.g., gemfibrozil) significantly increases the exposure (area under the serum concentration-time curve or AUC) and half-life (t½) 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)].
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)].
Topiramate or other carbonic anhydrase inhibitors (e.g., zonisamide, acetazolamide or dichlorphenamide) frequently causes a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of these drugs with ACTOPLUS MET XR may increase the risk for lactic acidosis. Consider more frequent monitoring of these patients.
Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see Clinical Pharmacology (12.3)]. Consider the benefits and risks of concomitant use.
Alcohol is known to potentiate the effect of metformin on lactate metabolism. Warn patients against excessive alcohol intake while receiving ACTOPLUS MET XR.
If hypoglycemia occurs in a patient coadministered ACTOPLUS MET XR and an insulin secretagogue (e.g., sulfonylurea), the dose of the insulin secretagogue should be reduced.
If hypoglycemia occurs in a patient coadministered ACTOPLUS MET XR 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.
Certain drugs tend to produce hyperglycemia and may lead to loss of glycemic control. These drugs include the thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers, and isoniazid. When such drugs are administered to a patient receiving ACTOPLUS MET XR, the patient should be closely observed for loss of blood glucose control. When such drugs are withdrawn from a patient receiving ACTOPLUS MET XR, the patient should be observed closely for hypoglycemia.
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 ACTOPLUS MET XR and topiramate are used concomitantly, monitor patients for adequate glycemic control.
Limited data with ACTOPLUS MET XR or pioglitazone in pregnant women are not sufficient to determine a drug-associated risk for major birth defects or miscarriage. Published studies with metformin use during pregnancy have not reported a clear association with metformin and major birth defect or miscarriage risk [see Data]. There are risks to the mother and fetus associated with poorly controlled diabetes in pregnancy [see Clinical Considerations].
In animal reproduction studies, no adverse developmental effects were observed when pioglitazone was administered to pregnant rats and rabbits during organogenesis at exposures up to 5- and 35-times the 45 mg clinical dose, respectively, based on body surface area. No adverse developmental effects were observed when metformin was administered to pregnant Sprague Dawley rats and rabbits during the period of organogenesis at doses up to 2- to 6-times, respectively, a 2000 mg clinical dose, based on body surface area [see Data].
The estimated background risk of major birth defects is 6-10% in women with pre-gestational diabetes with a HbA1c >7 and has been reported to be as high as 20-25% in women with a HbA1c >10. The estimated background risk of miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Poorly controlled diabetes in pregnancy increases the maternal risk for diabetic ketoacidosis, pre-eclampsia, spontaneous abortions, preterm delivery, still birth and delivery complications. Poorly controlled diabetes increases the fetal risk for major birth defects, still birth, and macrosomia related morbidity.
Published data from post-marketing studies have not reported a clear association with metformin and major birth defects, miscarriage, or adverse maternal or fetal outcomes when metformin was used during pregnancy. However, these studies cannot definitely establish the absence of any metformin-associated risk because of methodological limitations, including small sample size and inconsistent comparator groups.
Pioglitazone and Metformin hydrochloride:
Animal reproduction studies were not conducted with the combined products in ACTOPLUS MET XR. The following data are based on studies conducted with the individual components of ACTOPLUS MET XR.
Pioglitazone:
Pioglitazone administered to pregnant rats during organogenesis did not cause adverse developmental effects at a dose of 20 mg/kg (~5-times the 45 mg clinical dose), but delayed parturition and reduced embryofetal viability at 40 and 80 mg/kg, or ≥9-times the 45 mg clinical dose, by body surface area. In pregnant rabbits administered pioglitazone during organogenesis, no adverse developmental effects were observed at 80 mg/kg (~35-times the 45 mg clinical dose), but reduced embryofetal viability at 160 mg/kg, or ~69-times the 45 mg clinical dose, by body surface area. When pregnant rats received pioglitazone during late gestation and lactation, delayed postnatal development, attributed to decreased body weight occurred in offspring at maternal doses of 10 mg/kg and above or ≥2-times the 45 mg clinical dose, by body surface area.
Metformin hydrochloride:
Metformin hydrochloride did not cause adverse developmental effects when administered to pregnant Sprague Dawley rats and rabbits up to 600 mg/kg/day during the period of organogenesis. This represents an exposure of about 2- to 6-times a 2000 mg clinical dose based on body surface area (mg/m2) for rats and rabbits, respectively.
There is no information regarding the presence of ACTOPLUS MET XR or pioglitazone in human milk, the effects on the breastfed infant, or the effects on milk production. Pioglitazone is present in rat milk; however, due to species-specific differences in lactation physiology, animal data may not reliably predict drug levels in human milk. Limited published studies report that metformin is present in human milk [see Data]. However, there is insufficient information on the effects of metformin on the breastfed infant and no available information on the effects of metformin on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for ACTOPLUS MET XR and any potential adverse effects on the breastfed infant from ACTOPLUS MET XR or from the underlying maternal condition.
Published clinical lactation studies report that metformin is present in human milk which resulted in infant doses approximately 0.11% to 1% of the maternal weight-adjusted dosage and a milk/plasma ratio ranging between 0.13 and 1. However, the studies were not designed to definitely establish the risk of use of metformin during lactation because of small sample size and limited adverse event data collected in infants.
Discuss the potential for unintended pregnancy with premenopausal women as therapy with ACTOPLUS MET XR may result in ovulation in some premenopausal anovulatory women.
Safety and effectiveness of ACTOPLUS MET XR in pediatric patients have not been established.
ACTOPLUS MET XR is not recommended for use in pediatric patients based on adverse effects observed in adults, including fluid retention and congestive heart failure, fractures, and urinary bladder tumors [see Warnings and Precautions (5.1, 5.3, 5.6, 5.7)].
A total of 92 patients (15.2%) treated with pioglitazone in the three pooled 16- to 26-week double-blind, placebo-controlled, monotherapy trials were ≥65 years old and two patients (0.3%) were ≥75 years old. In the two pooled 16- to 24-week add-on to sulfonylurea trials, 201 patients (18.7%) treated with pioglitazone were ≥65 years old and 19 (1.8%) were ≥75 years old. In the two pooled 16- to 24-week add-on to metformin trials, 155 patients (15.5%) treated with pioglitazone were ≥65 years old and 19 (1.9%) were ≥75 years old. In the two pooled 16- to 24-week add-on to insulin trials, 272 patients (25.4%) treated with pioglitazone were ≥65 years old and 22 (2.1%) were ≥75 years old.
In PROactive, 1068 patients (41.0%) treated with pioglitazone were ≥65 years old and 42 (1.6%) were ≥75 years old.
In pharmacokinetic studies with pioglitazone, no significant differences were observed in pharmacokinetic parameters between elderly and younger patients [see Clinical Pharmacology (12.3)].
Although clinical experiences have not identified differences in effectiveness and safety between the elderly (≥65 years) and younger patients, these conclusions are limited by small sample sizes for patients ≥75 years old.
Controlled clinical studies of metformin did not include sufficient numbers of elderly patients to determine whether they respond differently from younger patients, although other reported clinical experience has not identified differences in responses between the elderly and young patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy and the higher risk of lactic acidosis. Assess renal function more frequently in elderly patients [see Warnings and Precautions (5.2) and Dosage and Administration (2.2)].
Metformin is substantially excreted by the kidney, and the risk of metformin accumulation and lactic acidosis increases with the degree of renal impairment. ACTOPLUS MET XR is contraindicated in severe renal impairment, patients with an estimated glomerular filtration rate (eGFR) below 30 mL/min/1.73 m2 [see Dosage and Administration (2.2), Contraindications (4), Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)].
Use of metformin in patients with hepatic impairment has been associated with some cases of lactic acidosis. ACTOPLUS MET XR is not recommended in patients with hepatic impairment [see Warnings and Precautions (5.2)].
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