Pioglitazone (Page 4 of 8)

11 DESCRIPTION

Pioglitazone tablets are an oral antidiabetic medication.

Pioglitazone [(±)-5-[[4-[2-(5-ethyl-2-pyridinyl) ethoxy] phenyl] methyl]-2,4-] thiazolidinedione monohydrochloride contains one asymmetric carbon, and the compound is synthesized and used as the racemic mixture. The two enantiomers of pioglitazone interconvert in vivo. No differences were found in the pharmacologic activity between the two enantiomers. The structural formula is as shown:

Pioglitazone hydrochloride chemical structure
(click image for full-size original)

Pioglitazone hydrochloride is an odorless white crystalline powder that has a molecular formula of C19 H20 N2 O3 S•HCl and a molecular weight of 392.90 daltons. It is soluble in N,N -dimethylformamide, slightly soluble in anhydrous ethanol, very slightly soluble in acetone and acetonitrile, practically insoluble in water, and insoluble in ether.

Pioglitazone Tablets are available as a tablet for oral administration containing 15 mg, 30 mg, or 45 mg of pioglitazone (as the base) formulated with the following excipients: lactose monohydrate NF, hydroxypropylcellulose NF, carboxymethylcellulose calcium NF, and magnesium stearate NF.

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Pioglitazone tablets are a thiazolidinedione that depends on the presence of insulin for its mechanism of action. Pioglitazone tablets decrease insulin resistance in the periphery and in the liver resulting in increased insulin-dependent glucose disposal and decreased hepatic glucose output. Pioglitazone is not an insulin secretagogue. Pioglitazone is an agonist for peroxisome proliferator-activated receptor-gamma (PPARγ). PPAR receptors are found in tissues important for insulin action such as adipose tissue, skeletal muscle, and liver. Activation of PPARγ nuclear receptors modulates the transcription of a number of insulin responsive genes involved in the control of glucose and lipid metabolism.

In animal models of diabetes, pioglitazone reduces the hyperglycemia, hyperinsulinemia, and hypertriglyceridemia characteristic of insulin-resistant states such as type 2 diabetes. The metabolic changes produced by pioglitazone result in increased responsiveness of insulin-dependent tissues and are observed in numerous animal models of insulin resistance.

Because pioglitazone enhances the effects of circulating insulin (by decreasing insulin resistance), it does not lower blood glucose in animal models that lack endogenous insulin.

12.2 Pharmacodynamics

Clinical studies demonstrate that pioglitazone tablets improve insulin sensitivity in insulin-resistant patients. Pioglitazone tablets enhance cellular responsiveness to insulin, increase insulin-dependent glucose disposal and improve hepatic sensitivity to insulin. In patients with type 2 diabetes, the decreased insulin resistance produced by pioglitazone tablets results in lower plasma glucose concentrations, lower plasma insulin concentrations, and lower HbA1c values. In controlled clinical trials, pioglitazone tablets had an additive effect on glycemic control when used in combination with a sulfonylurea, metformin, or insulin [see Clinical Studies (14.2)].

Patients with lipid abnormalities were included in clinical trials with pioglitazone tablets. Overall, patients treated with pioglitazone tablets had mean decreases in serum triglycerides, mean increases in HDL cholesterol, and no consistent mean changes in LDL and total cholesterol. There is no conclusive evidence of macrovascular benefit with pioglitazone tablets or any other antidiabetic medication [see Warnings and Precautions (5.9) and Adverse Reactions (6.1)].

In a 26-week, placebo-controlled, dose-ranging monotherapy study, mean serum triglycerides decreased in the 15 mg, 30 mg, and 45 mg pioglitazone tablets dose groups compared to a mean increase in the placebo group. Mean HDL cholesterol increased to a greater extent in patients treated with pioglitazone tablets than in the placebo-treated patients. There were no consistent differences for LDL and total cholesterol in patients treated with pioglitazone tablets compared to placebo (see Table 14).

Table 14. Lipids in a 26-Week Placebo-Controlled Monotherapy Dose-Ranging Study
Placebo Pioglitazone Tablets 15 mg Once Daily Pioglitazone Tablets 30 mg Once Daily Pioglitazone Tablets 45 mg Once Daily
*
Adjusted for baseline, pooled center, and pooled center by treatment interaction
p <0.05 versus placebo

Triglycerides (mg/dL)

N=79

N=79

N=84

N=77

Baseline (mean)

263

284

261

260

Percent change from baseline (adjusted mean *)

4.8%

-9.0%

-9.6%

-9.3%

HDL Cholesterol (mg/dL)

N=79

N=79

N=83

N=77

Baseline (mean)

42

40

41

41

Percent change from baseline (adjusted mean *)

8.1%

14.1%

12.2%

19.1%

LDL Cholesterol (mg/dL)

N=65

N=63

N=74

N=62

Baseline (mean)

139

132

136

127

Percent change from baseline (adjusted mean *)

4.8%

7.2%

5.2%

6.0%

Total Cholesterol (mg/dL)

N=79

N=79

N=84

N=77

Baseline (mean)

225

220

223

214

Percent change from baseline (adjusted mean *)

4.4%

4.6%

3.3%

6.4%

In the two other monotherapy studies (16 weeks and 24 weeks) and in combination therapy studies with sulfonylurea (16 weeks and 24 weeks), metformin (16 weeks and 24 weeks) or insulin (16 weeks and 24 weeks), the results were generally consistent with the data above.

All MedLibrary.org resources are included in as near-original form as possible, meaning that the information from the original provider has been rendered here with only typographical or stylistic modifications and not with any substantive alterations of content, meaning or intent.

This site is provided for educational and informational purposes only, in accordance with our Terms of Use, and is not intended as a substitute for the advice of a medical doctor, nurse, nurse practitioner or other qualified health professional.

Privacy Policy | Copyright © 2024. All Rights Reserved.