Mechanism of Action
ACTOS is a thiazolidinedione antidiabetic agent that depends
on the presence of insulin for its mechanism of action. ACTOS decreases
insulin resistance in the periphery and in the liver resulting in increased
insulin-dependent glucose disposal and decreased hepatic glucose output. Unlike
sulfonylureas, pioglitazone is not an insulin secretagogue. Pioglitazone is a
potent 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.
Since pioglitazone enhances the effects of circulating
insulin (by decreasing insulin resistance), it does not lower blood glucose in
animal models that lack endogenous insulin.
Pharmacokinetics and Drug Metabolism
Serum concentrations of total pioglitazone (pioglitazone
plus active metabolites) remain elevated 24 hours after once daily dosing.
Steady-state serum concentrations of both pioglitazone and total pioglitazone
are achieved within 7 days. At steady-state, two of the pharmacologically
active metabolites of pioglitazone, Metabolites III (M-III) and IV (M-IV),
reach serum concentrations equal to or greater than pioglitazone. In both
healthy volunteers and in patients with type 2 diabetes, pioglitazone comprises
approximately 30% to 50% of the peak total pioglitazone serum concentrations
and 20% to 25% of the total area under the serum concentration-time curve
(AUC).
Maximum serum concentration (Cmax), AUC, and trough serum
concentrations (Cmin) for both pioglitazone and total pioglitazone increase
proportionally at doses of 15 mg and 30 mg per day. There is a slightly less
than proportional increase for pioglitazone and total pioglitazone at a dose of
60 mg per day.
Absorption
Following oral administration, in the fasting state,
pioglitazone is first measurable in serum within 30 minutes, with peak
concentrations observed within 2 hours. Food slightly delays the time to peak
serum concentration to 3 to 4 hours, but does not alter the extent of absorption.
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. Metabolites M-III and M-IV also are
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-II and M-IV (hydroxy derivatives of pioglitazone)
and M-III (keto derivative of pioglitazone) are pharmacologically active in
animal models of type 2 diabetes. In addition to pioglitazone, M-III and M-IV
are the principal drug-related species found in human serum following multiple
dosing. At steady-state, in both healthy volunteers and in patients with type
2 diabetes, pioglitazone comprises approximately 30% to 50% of the total peak
serum concentrations and 20% to 25% of the total AUC.
In vitro data demonstrate that multiple CYP isoforms
are involved in the metabolism of pioglitazone. The cytochrome P450 isoforms
involved are CYP2C8 and, to a lesser degree, CYP3A4 with additional
contributions from a variety of other isoforms including the mainly
extrahepatic CYP1A1. In vivo studies of pioglitazone in combination with P450
inhibitors and substrates have been performed (see DRUG INTERACTIONS).
Urinary 6ß-hydroxycortisol/cortisol ratios measured in patients treated with
ACTOS 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 of pioglitazone and total
pioglitazone ranges from 3 to 7 hours and 16 to 24 hours, respectively.
Pioglitazone has an apparent clearance, CL/F, calculated to be 5 to 7 L/hr.
Special Populations
Renal Insufficiency
The serum elimination half-life of pioglitazone, M-III, and
M-IV remains unchanged in patients with moderate (creatinine clearance 30 to 60
mL/min) to severe (creatinine clearance < 30 mL/min) renal impairment when
compared to normal subjects. No dose adjustment in patients with renal
dysfunction is recommended (see DOSAGE AND ADMINISTRATION).
Hepatic Insufficiency
Compared with normal controls, subjects with impaired
hepatic function (Child-Pugh Grade B/C) have an approximate 45% reduction in
pioglitazone and total pioglitazone mean peak concentrations but no change in
the mean AUC values.
ACTOS therapy should not be initiated if the patient exhibits clinical evidence
of active liver disease or serum transaminase levels (ALT) exceed 2.5 times
the upper limit of normal (see PRECAUTIONS, Hepatic
Effects).
Elderly
In healthy elderly subjects, peak serum concentrations of
pioglitazone and total pioglitazone are not significantly different, but AUC
values are slightly higher and the terminal half-life values slightly longer
than for younger subjects. These changes were not of a magnitude that would be
considered clinically relevant.
Pediatrics
Pharmacokinetic data in the pediatric population are not
available.
Gender
The mean Cmax and AUC values were increased 20% to 60% in
females. As monotherapy and in combination with sulfonylurea, metformin, or
insulin, ACTOS improved glycemic control in both males and females. In
controlled clinical trials, hemoglobin A1c (HbA1c)
decreases from baseline were generally greater for females than for males
(average mean difference in HbA1c 0.5%). Since 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
The following drugs were studied in healthy volunteers with
a co-administration of ACTOS 45 mg once daily. Listed below are the results:
Oral Contraceptives: Co-administration of ACTOS (45 mg once daily)
and an oral contraceptive (1 mg norethindrone plus 0.035 mg ethinyl estradiol
once daily) for 21 days, resulted in 11% and 11-14% decrease in ethinyl estradiol
AUC (0-24h) and Cmax respectively. There were no significant changes in norethindrone
AUC (0-24h) and Cmax. In view of the high variability of ethinyl estradiol
pharmacokinetics, the clinical significance of this finding is unknown.
Fexofenadine HCl: Co-administration of ACTOS for 7 days with
60 mg fexofenadine administered orally twice daily resulted in no significant
effect on pioglitazone pharmacokinetics. ACTOS had no significant effect on
fexofenadine pharmacokinetics.
Glipizide: Co-administration of ACTOS and 5 mg glipizide administered
orally once daily for 7 days did not alter the steady-state pharmacokinetics
of glipizide.
Digoxin: Co-administration of ACTOS with 0.25 mg digoxin administered
orally once daily for 7 days did not alter the steady-state pharmacokinetics
of digoxin.
Warfarin: Co-administration of ACTOS for 7 days with warfarin
did not alter the steady-state pharmacokinetics of warfarin. ACTOS has no clinically
significant effect on prothrombin time when administered to patients receiving
chronic warfarin therapy.
Metformin: Co-administration of a single dose of metformin (1000
mg) and ACTOS after 7 days of ACTOS did not alter the pharmacokinetics of the
single dose of metformin.
Midazolam: Administration of ACTOS for 15 days followed by a
single 7.5 mg dose of midazolam syrup resulted in a 26% reduction in midazolam
Cmax and AUC.
Ranitidine HCl: Co-administration of ACTOS for 7 days with ranitidine
administered orally twice daily for either 4 or 7 days resulted in no significant
effect on pioglitazone pharmacokinetics. ACTOS showed no significant effect
on ranitidine pharmacokinetics.
Nifedipine ER: Co-administration of ACTOS for 7 days with 30
mg nifedipine ER administered orally once daily for 4 days to male and female
volunteers resulted in least square mean (90% CI) values for unchanged nifedipine
of 0.83 (0.73 - 0.95) for Cmax and 0.88 (0.80 - 0.96) for AUC. In view of
the high variability of nifedipine pharmacokinetics, the clinical significance
of this finding is unknown.
Ketoconazole: Co-administration of ACTOS for 7 days with ketoconazole
200 mg administered twice daily resulted in least square mean (90% CI) values
for unchanged pioglitazone of 1.14 (1.06 - 1.23) for Cmax, 1.34 (1.26 - 1.41)
for AUC and 1.87 (1.71 - 2.04) for Cmin.
Atorvastatin Calcium: Co-administration of ACTOS for 7 days with
atorvastatin calcium (LIPITOR®) 80 mg once daily resulted in least square
mean (90% CI) values for unchanged pioglitazone of 0.69 (0.57 - 0.85) for Cmax,
0.76 (0.65 - 0.88) for AUC and 0.96 (0.87 - 1.05) for Cmin. For unchanged
atorvastatin the least square mean (90% CI) values were 0.77 (0.66 - 0.90) for
Cmax, 0.86 (0.78 - 0.94) for AUC and 0.92 (0.82 - 1.02) for Cmin.
Theophylline: Co-administration of ACTOS for 7 days with theophylline
400 mg administered twice daily resulted in no change in the pharmacokinetics
of either drug.
Cytochrome P450: See PRECAUTIONS
Gemfibrozil: Concomitant administration of gemfibrozil (oral
600 mg twice daily), an inhibitor of CYP2C8, with pioglitazone (oral 30 mg)
in 10 healthy volunteers pre-treated for 2 days prior with gemfibrozil (oral
600 mg twice daily) resulted in pioglitazone exposure (AUC0-24) being 226% of
the pioglitazone exposure in the absence of gemfibrozil (see PRECAUTIONS).1
Rifampin: Concomitant administration of rifampin (oral 600 mg
once daily), an inducer of CYP2C8 with pioglitazone (oral 30 mg) in 10 healthy
volunteers pre-treated for 5 days prior with rifampin (oral 600 mg once daily)
resulted in a decrease in the AUC of pioglitazone by 54% (see PRECAUTIONS).2
Pharmacodynamics and Clinical Effects
Clinical studies demonstrate that ACTOS improves insulin
sensitivity in insulin-resistant patients. ACTOS enhances cellular
responsiveness to insulin, increases insulin-dependent glucose disposal,
improves hepatic sensitivity to insulin, and improves dysfunctional glucose
homeostasis. In patients with type 2 diabetes, the decreased insulin
resistance produced by ACTOS results in lower plasma glucose concentrations,
lower plasma insulin levels, and lower HbA1c values. Based on results from an
open-label extension study, the glucose lowering effects of ACTOS appear to
persist for at least one year. In controlled clinical trials, ACTOS in
combination with sulfonylurea, metformin, or insulin had an additive effect on
glycemic control.
Patients with lipid abnormalities were included in clinical
trials with ACTOS. Overall, patients treated with ACTOS had mean decreases in
triglycerides, mean increases in HDL cholesterol, and no consistent mean
changes in LDL and total cholesterol.
In a 26-week, placebo-controlled, dose-ranging study, mean
triglyceride levels decreased in the 15 mg, 30 mg, and 45 mg ACTOS dose groups
compared to a mean increase in the placebo group. Mean HDL levels increased to
a greater extent in patients treated with ACTOS than in the placebo-treated
patients. There were no consistent differences for LDL and total cholesterol
in patients treated with ACTOS compared to placebo (Table 1).
Table 1 : Lipids in a 26-Week Placebo-Controlled Monotherapy
Dose-Ranging Study
| |
Placebo |
ACTOS 15 mg Once Daily |
ACTOS 30 mg Once Daily |
ACTOS 45 mg Once Daily |
| Triglycerides (mg/dL) |
N=79 |
N=79 |
N=84 |
N=77 |
| Baseline (mean) |
262.8 |
283.8 |
261.1 |
259.7 |
| Percent change from baseline (mean) |
4.8% |
-9.0% |
-9.6% |
-9.3% |
| HDL Cholesterol (mg/dL) |
N=79 |
N=79 |
N=83 |
N=77 |
| Baseline (mean) |
41.7 |
40.4 |
40.8 |
40.7 |
| Percent change from baseline (mean) |
8.1% |
14.1% |
12.2% |
19.1% |
| LDL Cholesterol (mg/dL) |
N=65 |
N=63 |
N=74 |
N=62 |
| Baseline (mean) |
138.8 |
131.9 |
135.6 |
126.8 |
| Percent change from baseline (mean) |
4.8% |
7.2% |
5.2% |
6.0% |
| Total Cholesterol (mg/dL) |
N=79 |
N=79 |
N=84 |
N=77 |
| Baseline (mean) |
224.6 |
220.0 |
222.7 |
213.7 |
| Percent change from baseline (mean) |
4.4% |
4.6% |
3.3% |
6.4% |
In the two other monotherapy studies (24 weeks and 16 weeks)
and in combination therapy studies with sulfonylurea (24 weeks and 16 weeks)
and metformin (24 weeks and 16 weeks), the results were generally consistent
with the data above. In placebo-controlled trials, the placebo-corrected mean
changes from baseline decreased 5% to 26% for triglycerides and increased 6% to
13% for HDL in patients treated with ACTOS. A similar pattern of results was
seen in 24-week combination therapy studies of ACTOS with sulfonylurea or
metformin.
In a combination therapy study with insulin (16 weeks), the
placebo-corrected mean percent change from baseline in triglyceride values for
patients treated with ACTOS was also decreased. A placebo-corrected mean
change from baseline in LDL cholesterol of 7% was observed for the 15 mg dose
group. Similar results to those noted above for HDL and total cholesterol were
observed. A similar pattern of results was seen in a 24-week combination
therapy study with ACTOS with insulin.
Clinical Studies
Monotherapy
In the U.S., three randomized, double-blind,
placebo-controlled trials with durations from 16 to 26 weeks were conducted to
evaluate the use of ACTOS as monotherapy in patients with type 2 diabetes.
These studies examined ACTOS at doses up to 45 mg or placebo once daily in 865
patients.
In a 26-week, dose-ranging study, 408 patients with type 2
diabetes were randomized to receive 7.5 mg, 15 mg, 30 mg, or 45 mg of ACTOS,
or placebo once daily. Therapy with any previous antidiabetic agent was
discontinued 8 weeks prior to the double-blind period. Treatment with 15 mg,
30 mg, and 45 mg of ACTOS produced statistically significant improvements in
HbA1c and fasting plasma glucose (FPG) at endpoint compared to placebo (Figure
1, Table 2).
Figure 1 shows the time course for changes in FPG and HbA1c
for the entire study population in this 26-week study.
Figure 1 : Mean Change from Baseline for FPG and HbA1c in
a 26-Week Placebo-Controlled Dose-Ranging Study
Table 2 shows HbA1c and FPG values for the entire study
population.
Table 2 : Glycemic Parameters in a 26-Week Placebo-Controlled
Dose-Ranging Study
| |
Placebo |
ACTOS 15 mg Once Daily |
ACTOS 30 mg Once Daily |
ACTOS 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+) |
|
-1.0* |
-1.0* |
-1.6* |
| FPG (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+) |
|
-39* |
-41* |
-65* |
+ Adjusted for baseline, pooled center, and pooled center
by treatment interaction
* p ≤ 0.050 vs. placebo |
The study population included patients not previously treated with antidiabetic
medication (naïve; 31%) and patients who were receiving antidiabetic medication
at the time of study enrollment (previously treated; 69%). The data for the
naïve and previously-treated patient subsets are shown in Table 3. All patients
entered an 8 week washout/run-in period prior to double-blind treatment. This
run-in period was associated with little change in HbA1c and FPG values from
screening to baseline for the naïve patients; however, for the previously-treated
group, washout from previous antidiabetic medication resulted in deterioration
of glycemic control and increases in HbA1c and FPG. Although most patients
in the previously-treated group had a decrease from baseline in HbA1c and FPG
with ACTOS, in many cases the values did not return to screening levels by the
end of the study. The study design did not permit the evaluation of patients
who switched directly to ACTOS from another antidiabetic agent.
Table 3 : Glycemic Parameters in a 26-Week Placebo-Controlled
Dose-Ranging Study
| |
Placebo |
ACTOS 15 mg Once Daily |
ACTOS 30 mg Once Daily |
ACTOS 45 mg Once Daily |
| Naïve to Therapy |
|
|
|
|
| HbA1c (%) |
N=25 |
N=26 |
N=26 |
N=21 |
| Screening (mean) |
9.3 |
10.0 |
9.5 |
9.8 |
| Baseline (mean) |
9.0 |
9.9 |
9.3 |
10.0 |
| Change from baseline (adjusted mean*) |
0.6 |
-0.8 |
-0.6 |
-1.9 |
| Difference from placebo (adjusted mean*) |
|
-1.4 |
-1.3 |
-2.6 |
| FPG (mg/dL) |
N=25 |
N=26 |
N=26 |
N=21 |
| Screening (mean) |
223 |
245 |
239 |
239 |
| Baseline (mean) |
229 |
251 |
225 |
235 |
| Change from baseline (adjusted mean*) |
16 |
-37 |
-41 |
-64 |
| Difference from placebo (adjusted mean*) |
|
-52 |
-56 |
-80 |
| Previously Treated |
|
|
|
|
| HbA1c (%) |
N=54 |
N=53 |
N=59 |
N=55 |
| Screening (mean) |
9.3 |
9.0 |
9.1 |
9.0 |
| Baseline (mean) |
10.9 |
10.4 |
10.4 |
10.6 |
| Change from baseline (adjusted mean*) |
0.8 |
-0.1 |
-0.0 |
-0.6 |
| Difference from placebo (adjusted mean*) |
|
-1.0 |
-0.9 |
-1.4 |
| FPG (mg/dL) |
N=54 |
N=53 |
N=58 |
N=56 |
| Screening (mean) |
222 |
209 |
230 |
215 |
| Baseline (mean) |
285 |
275 |
286 |
292 |
| Change from baseline (adjusted mean*) |
4 |
-32 |
-27 |
-55 |
| Difference from placebo (adjusted mean*) |
|
-36 |
-31 |
-59 |
| * Adjusted for baseline and pooled center |
In a 24-week, placebo-controlled study, 260 patients with
type 2 diabetes were randomized to one of two forced-titration ACTOS treatment
groups or a mock titration placebo group. Therapy with any previous
antidiabetic agent was discontinued 6 weeks prior to the double-blind period.
In one ACTOS treatment group, patients received an initial dose of 7.5 mg once
daily. After four weeks, the dose was increased to 15 mg once daily and after
another four weeks, the dose was increased to 30 mg once daily for the
remainder of the study (16 weeks). In the second ACTOS treatment group,
patients received an initial dose of 15 mg once daily and were titrated to 30
mg once daily and 45 mg once daily in a similar manner. Treatment with ACTOS,
as described, produced statistically significant improvements in HbA1c and FPG
at endpoint compared to placebo (Table 4).
Table 4 : Glycemic Parameters in a 24-Week Placebo-Controlled
Forced-Titration Study
| |
Placebo |
ACTOS 30 mg + Once Daily |
ACTOS 45 mg + Once Daily |
| Total Population |
|
|
|
| HbA1c (%) |
N=83 |
N=85 |
N=85 |
| Baseline (mean) |
10.8 |
10.3 |
10.8 |
| Change from baseline (adjusted mean++) |
0.9 |
-0.6 |
-0.6 |
| Difference from placebo (adjusted mean++) |
|
-1.5* |
-1.5* |
| FPG (mg/dL) |
N=78 |
N=82 |
N=85 |
| Baseline (mean) |
279 |
268 |
281 |
| Change from baseline (adjusted mean++) |
18 |
-44 |
-50 |
| Difference from placebo (adjusted mean++) |
|
-62* |
-68* |
+ Final dose in forced titration
++ Adjusted for baseline, pooled center, and pooled center by treatment
interaction
* p ≤ 0.050 vs. placebo |
For patients who had not been previously treated with
antidiabetic medication (24%), mean values at screening were 10.1% for HbA1c
and 238 mg/dL for FPG. At baseline, mean HbA1c was 10.2% and mean FPG was 243
mg/dL. Compared with placebo, treatment with ACTOS titrated to a final dose
of 30 mg and 45 mg resulted in reductions from baseline in mean HbA1c of 2.3%
and 2.6% and mean FPG of 63 mg/dL and 95 mg/dL, respectively. For patients who
had been previously treated with antidiabetic medication (76%), this medication
was discontinued at screening. Mean values at screening were 9.4% for HbA1c
and 216 mg/dL for FPG. At baseline, mean HbA1c was 10.7% and mean FPG was 290
mg/dL. Compared with placebo, treatment with ACTOS titrated to a final dose of
30 mg and 45 mg resulted in reductions from baseline in mean HbA1c of 1.3% and
1.4% and mean FPG of 55 mg/dL and 60 mg/dL, respectively. For many
previously-treated patients, HbA1c and FPG had not returned to screening levels
by the end of the study.
In a 16-week study, 197 patients with type 2 diabetes were
randomized to treatment with 30 mg of ACTOS or placebo once daily. Therapy
with any previous antidiabetic agent was discontinued 6 weeks prior to the
double-blind period. Treatment with 30 mg of ACTOS produced statistically
significant improvements in HbA1c and FPG at endpoint compared to placebo
(Table 5).
Table 5 : Glycemic Parameters in a 16-Week Placebo-Controlled
Study
| |
Placebo |
ACTOS 30 mg
Once Daily |
| Total Population |
|
|
| HbA1c (%) |
N=93 |
N=100 |
| Baseline (mean) |
10.3 |
10.5 |
| Change from baseline (adjusted mean+) |
0.8 |
-0.6 |
| Difference from placebo (adjusted mean+) |
|
-1.4* |
| FPG (mg/dL) |
N=91 |
N=99 |
| Baseline (mean) |
270 |
273 |
| Change from baseline (adjusted mean+) |
8 |
-50 |
| Difference from placebo (adjusted mean+) |
|
-58* |
+ Adjusted for baseline, pooled center, and pooled center
by treatment interaction
* p ≤ 0.050 vs. placebo |
For patients who had not been previously treated with antidiabetic medication
(40%), mean values at screening were 10.3% for HbA1c and 240 mg/dL for FPG.
At baseline, mean HbA1c was 10.4% and mean FPG was 254 mg/dL. Compared with
placebo, treatment with ACTOS 30 mg resulted in reductions from baseline in
mean HbA1c of 1.0% and mean FPG of 62 mg/dL. For patients who had been previously
treated with antidiabetic medication (60%), this medication was discontinued
at screening. Mean values at screening were 9.4% for HbA1c and 216 mg/dL for
FPG. At baseline, mean HbA1c was 10.6% and mean FPG was 287 mg/dL. Compared
with placebo, treatment with ACTOS 30 mg resulted in reductions from baseline
in mean HbA1c of 1.3% and mean FPG of 46 mg/dL. For many previously-treated
patients, HbA1c and FPG had not returned to screening levels by the end of the
study.
Combination Therapy
Three 16-week, randomized, double-blind, placebo-controlled
clinical studies and three 24-week, randomized, double-blind, dose-controlled
clinical studies were conducted to evaluate the effects of ACTOS on glycemic
control in patients with type 2 diabetes who were inadequately controlled
(HbA1c ≥ 8%) despite current therapy with a sulfonylurea, metformin, or
insulin. Previous diabetes treatment may have been monotherapy or combination
therapy.
ACTOS Plus Sulfonylurea Studies
Two clinical studies were conducted with ACTOS in
combination with a sulfonylurea. Both studies included patients with type 2
diabetes on a sulfonylurea, either alone or in combination with another
antidiabetic agent. All other antidiabetic agents were withdrawn prior to
starting study treatment. In the first study, 560 patients were randomized to
receive 15 mg or 30 mg of ACTOS or placebo once daily for 16 weeks in addition
to their current sulfonylurea regimen. When compared to placebo at Week 16,
the addition of ACTOS to the sulfonylurea significantly reduced the mean HbA1c
by 0.9% and 1.3% and mean FPG by 39 mg/dL and 58 mg/dL for the 15 mg and 30 mg
doses, respectively.
In the second study, 702 patients were randomized to receive
30 mg or 45 mg of ACTOS once daily for 24 weeks in addition to their current
sulfonylurea regimen. The mean reductions from baseline at Week 24 in HbA1c
were 1.55% and 1.67% for the 30 mg and 45 mg doses, respectively. Mean
reductions from baseline in FPG were 51.5 mg/dL and 56.1 mg/dL.
The therapeutic effect of ACTOS in combination with
sulfonylurea was observed in patients regardless of whether the patients were
receiving low, medium, or high doses of sulfonylurea.
ACTOS Plus Metformin Studies
Two clinical studies were conducted with ACTOS in
combination with metformin. Both studies included patients with type 2
diabetes on metformin, either alone or in combination with another antidiabetic
agent. All other antidiabetic agents were withdrawn prior to starting study
treatment. In the first study, 328 patients were randomized to receive either
30 mg of ACTOS or placebo once daily for 16 weeks in addition to their current
metformin regimen. When compared to placebo at Week 16, the addition of ACTOS
to metformin significantly reduced the mean HbA1c by 0.8% and decreased the
mean FPG by 38 mg/dL.
In the second study, 827 patients were randomized to receive
either 30 mg or 45 mg of ACTOS once daily for 24 weeks in addition to their
current metformin regimen. The mean reductions from baseline at Week 24 in
HbA1c were 0.80% and 1.01% for the 30 mg and 45 mg doses, respectively. Mean
reductions from baseline in FPG were 38.2 mg/dL and 50.7 mg/dL.
The therapeutic effect of ACTOS in combination with
metformin was observed in patients regardless of whether the patients were
receiving lower or higher doses of metformin.
ACTOS Plus Insulin Studies
Two clinical studies were conducted with ACTOS in
combination with insulin. Both studies included patients with type 2 diabetes
on insulin, either alone or in combination with another antidiabetic agent.
All other antidiabetic agents were withdrawn prior to starting study
treatment. In the first study, 566 patients receiving a median of 60.5 units
per day of insulin were randomized to receive either 15 mg or 30 mg of ACTOS or
placebo once daily for 16 weeks in addition to their insulin regimen. When
compared to placebo at Week 16, the addition of ACTOS to insulin significantly
reduced both HbA1c by 0.7% and 1.0% and FPG by 35 mg/dL and 49 mg/dL for the
15 mg and 30 mg dose, respectively. In the second study, 690 patients
receiving a median of 60.0 units per day of insulin received either 30 mg or 45
mg of ACTOS once daily for 24 weeks in addition to their current insulin
regimen. The mean reductions from baseline at Week 24 in HbA1c were 1.17% and
1.46% for the 30 mg and 45 mg doses, respectively. Mean reductions from
baseline in FPG were 31.9 mg/dL and 45.8 mg/dL. Improved glycemic control was
accompanied by mean decreases from baseline in insulin dose requirements of
6.0% and 9.4% per day for the 30 mg and 45 mg dose, respectively. The
therapeutic effect of ACTOS in combination with insulin was observed in
patients regardless of whether the patients were receiving lower or higher
doses of insulin.
REFERENCES
1.Deng, LJ, et al. Effect of gemfibrozil on the pharmacokinetics
of pioglitazone. Eur J Clin Pharmacol 2005; 61: 831-836, Table 1.
2.Jaakkola, T, et al. Effect of rifampicin on the pharmacokinetics
of pioglitazone. Clin Pharmacol Brit Jour 2006; 61:1 70-78.
Last updated on RxList: 9/28/2009