Pioglitazone

Absorption

Following oral administration of pioglitazone, peak serum concentrations are observed within 2 hours (Tmax) - food slightly delays the time to peak serum concentration, increasing Tmax to approximately 3-4 hours, but does not alter the extent of absorption. Steady-state concentrations of both parent drug and its primary active metabolites are achieved after 7 days of once-daily administration of pioglitazone. Cmax and AUC increase proportionately to administered doses.

Toxicity

The oral TDLo observed in mice is 24 mg/kg for 4 days and for rats is 3 mg/kg for 6 days.
One instance of overdose was reported during clinical trials with pioglitazone in which a patient took an oral dose of 120mg daily for four days, followed by 180mg daily for seven days - this patient did not report any adverse clinical symptoms during this time. In the event of overdosage, employ symptomatic and supportive measures according to the patient's clinical status.

Description

Pioglitazone is an agonist of the peroxisome proliferator-activated receptor γ (PPARγ; EC₅₀ = ~500-600 nM for both human and murine PPARγ). It is selective for PPARγ over PPARα, exhibiting low level activation of PPARα at 1 μM and 5.4-fold activation at a concentration of 10 μM. Pioglitazone inhibits pyruvate oxidation and glucose production in hepatocytes when used at a concentration of 10 μM. In vivo, pioglitazone (0.3-3 mg/kg per day) reduces hyperglycemia, hyperlipidemia, and hyperinsulinemia in a dose-dependent manner in male Wistar fatty rats. It reduces the number of lesions in a transgenic rat adenocarcinoma of prostate (TRAP) model. Pioglitazone (2.5 mg/kg) also decreases production of neuroinflammatory cytokines and reduces immobility in the forced swim and tail suspension tests in a mouse model of chronic mild stress, indicating antidepressant-like activity that can be reversed by the PPARγ antagonist GW9662 .

Description

Pioglitazone is a thiazolinedione drug that reduces blood glucose levels in diabetic patients. Takeda Pharmaceuticals launched it under the trade name Actos in 1999. Within 10 years, it became the world’s best-selling diabetes drug. Although it is relatively safe, some countries have stopped its sale because it is associated with bladder tumors.
As indicated in the images, pioglitazone is a racemic mixture of two enantiomers. Because the enantiomers interconvert in vivo,?no differences are seen between the two?in terms of pharmacological activity.
In 2015, Stéphane Prost, Philippe Leboulch, and colleagues at the Institute of Emerging Diseases & Innovative Therapies in France and Harvard Medical School discovered that pioglitazone can work with the cancer drug imatinib so that it not only stops the spread of chronic myeloid leukemia?but eliminates the cancer altogether. Cancer stem cells can “hide” from imatinib by becoming quiescent, but pioglitazone releases the cells from “hibernation” to allow the cancer drug to finish its job. The researchers are preparing for clinical trials on pioglitazone.

Originator

Actos ,Eli Lilly ,USA

The Uses of Pioglitazone

Pioglitazone shows antidiabetic activity in patients with type 2 diabetes mellitus.

The Uses of Pioglitazone

antihyperlipidemic, HMGCoA reductase inhibitor

Background

Pioglitazone is an antihyperglycemic used as an adjunct to diet, exercise, and other antidiabetic medications to manage type 2 diabetes mellitus. It is administered as a racemic mixture, though there is no pharmacologic difference between the enantiomers and they appear to interconvert in vivo with little consequence. The thiazolidinedione class of medications, which also includes rosiglitazone and troglitazone, exerts its pharmacological effect primarily by promoting insulin sensitivity and the improved uptake of blood glucose via agonism at the peroxisome proliferator-activated receptor-gamma (PPARγ). PPARs are ligand-activated transcription factors that are involved in the expression of more than 100 genes and affect numerous metabolic processes, most notably lipid and glucose homeostasis.
Thiazolidinediones, including pioglitazone, have fallen out of favor in recent years due to the presence of multiple adverse effects and warnings regarding their use (e.g. congestive heart failure, bladder cancer) and the availability of safer and more effective alternatives for patients with type 2 diabetes mellitus.

Indications

Pioglitazone is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. It is also available in combination with metformin, glimepiride, or alogliptin for the same indication.

What are the applications of Application

Pioglitazone is a PPAR agonist with potential antidiabetic characteristics

Definition

ChEBI: A member of the class of thiazolidenediones that is 1,3-thiazolidine-2,4-dione substituted by a benzyl group at position 5 which in turn is substituted by a 2-(5-ethylpyridin-2-yl)ethoxy group at position 4 of the phenyl ring. It exhibits hypoglycemic acti ity.

Indications

Pioglitazone is approved for use as monotherapy and in conjunction with metformin, sulfonylureas, and insulin. It is taken once a day with or without food. Though pioglitazone may also cause a small increase in low-density lipoprotein concentrations, there is usually a modest decrease in triglyceride levels, but it unclear whether this has any clinical significance or persists in the long term.

Manufacturing Process

To a solution of 2-(5-ethyl-2-pyridyl)ethanol (53.0 g) and 4-fluoronitrobenzene (47.0 g) in DMF (500 ml) was added portionwise under ice-cooling 60% sodium hydride in oil (16.0 g). The mixture was stirred under ice-cooling for one hour, then at room temperature for 30 min, poured into water and extracted with ether. The ether layer was washed with water and dried (MgSO4). The solvent was evaporated off to give 4-[2-(5-ethyl-2pyridyl)ethoxy]nitrobenzene as crystals (62.0 g, 62.9%). Recrystallization from ether-hexane gave colorless prisms, melting point 53°-54°C.
A solution of 4-[2-(5-ethyl-2-pyridyl)ethoxy]nitrobenzene (60.0 g) in methanol (500 ml) was hydrogenated at room temperature under one atmospheric pressure in the presence of 10% Pd-C (50% wet, 6.0 g). The catalyst was removed by filtration and the filtrate was concentrated under reduced pressure. The residual oil was dissolved in acetone (500 ml)methanol (200 ml). To the solution was added a 47% HBr aqueous solution (152 g). The mixture was cooled, to which was added dropwise a solution of NaNO2 (17.3 g) in water (30 ml) at a temperature not higher than 5°C. The whole mixture was stirred at 5°C for 20 min, then methyl acrylate (112 g) was added thereto and the temperature was raised to 38°C. Cuprous oxide (2.0 g) was added to the mixture in small portions with vigorous stirring. The reaction mixture was stirred until nitrogen gas evolution ceased, and was concentrated under reduced pressure. The concentrate was made alkaline with concentrated aqueous ammonia, and extracted with ethyl acetate. The ethyl acetate layer was washed with water and dried (MgSO4) The solvent was evaporated off to leave methyl 2-bromo-3-{4-[2-(5-ethyl-2pyridyl)ethoxy]phenyl}propionate as a crude oil (74.09 g, 85.7%).
A mixture of the crude oil of methyl 2-bromo-3-{4-[2-(5-ethyl-2pyridyl)ethoxy]phenyl}propionate (73.0 g) thiourea (14.2 g), sodium acetate (15.3 g) and ethanol (500 ml) was stirred for 3 hours under reflux. The reaction mixture was concentrated under reduced pressure, and the concentrate was neutralized with a saturated aqueous solution of sodium hydrogencarbonate, to which were added water (200 ml) and ether (100 ml). The whole mixture was stirred for 10 min to yield 5-{4-[2-(5-ethyl-2pyridyl)ethoxy]benzyl}-2-imino-4-thiazolidinone as crystals (0.3 g, 523.0%). Recrystallization from methanol gave colorless prisms, melting point 187°188°C, dec.
A solution of 5-{4-[2-(5-ethyl-2-pyridyl)ethoxy]benzyl}-2-imino-4thiazolidinone (23.5 g) in 2 N HCl (200 ml) was refluxed for 6 hours. The solvent was evaporated off under reduced pressure, and the residue was neutralized with a saturated aqueous solution of sodium hydrogencarbonate. The crystals (23.5 g, 97.5%) which precipitated were collected by filtrationand recrystallized from DMF-H2O to give 5-{4-[2-(5-ethyl-2pyridyl)ethoxy]benzyl}-2,4-thiazolidinedione as colorless needles (20.5 g, 86.9%), melting point 183°-184°C.
In practice it is usually used as hydrochloride salt.

brand name

Actos (Takeda).

Therapeutic Function

Antidiabetic

General Description

Pioglitazone, (±)-5-[[4-[2-(5-ethyl-2-pyridinyl)ethoxy]phenyl]methyl]-2,4-thiazolidinedione (Actos),is an odorless, white, crystalline powder that must be convertedto a salt such as its hydrochloride before it will haveany water solubility. Although the molecule contains one chiralcenter, the compound is used as the racemic mixture. Thisis primarily a result of the in vivo interconversion of the twoenantiomers. Thus, there are no differences in the pharmacologicalactivity of the two enantiomers.

Pharmacokinetics

Pioglitazone enhances cellular responsiveness to insulin, increases insulin-dependent glucose disposal, and improves impaired glucose homeostasis. In patients with type 2 diabetes mellitus, these effects result in lower plasma glucose concentrations, lower plasma insulin concentrations, and lower HbA1c values.
Significant fluid retention leading to the development/exacerbation of congestive heart failure has been reported with pioglitazone - avoid its use in patients in heart failure or at risk of developing heart failure. There is some evidence that pioglitazone may be associated with an increased risk of developing bladder cancer. Pioglitazone should not be used in patients with active bladder cancer and should be used with caution in patients with a history of bladder cancer.

Metabolism

Pioglitazone is extensively metabolized by both hydroxylation and oxidation - the resulting metabolites are also partly converted to glucuronide or sulfate conjugates. The pharmacologically active M-IV and M-III metabolites are the main metabolites found in human serum and their circulating concentrations are equal to, or greater than, those of the parent drug. The specific CYP isoenzymes involved in the metabolism of pioglitazone are CYP2C8 and, to a lesser degree, CYP3A4. There is also some evidence to suggest a contribution by extrahepatic CYP1A1.

storage

+4°C