COMPOSITION : Each tablet contains:-
Pioglitazone 15 mg
Metformin 500 mg
- Metformin belongs to class of medications called antidiabetics.It decreases the amount of glucose absorbed from the food and the amount ofglucose made by liver. Metformin also increases the body’s response to insulin(a natural substance that controls the amount of glucose in the blood).
- Pioglitazone belongs to class of thiazolidinedione. Pioglitazone decreases insulin resistance in the periphery and in the liver that helps the body make better use of insulin it produces and also decreases the glucose output from the liver.
Pioglitazone and Metformin Hydrochloride Tablets
In bioequivalence studies of pioglitazone and metformin hydrochloride tablets 15 mg/500 mg and 15 mg/850 mg, the area under the curve (AUC) and maximum concentration (Cmax) of both the pioglitazone and the metformin component following a single dose of the combination tablet were bioequivalent to ACTOS® 15 mg concomitantly administered with GLUCOPHAGE® (500 mg or 850 mg respectively) tablets under fasted conditions in healthy subjects.Administration of pioglitazone and metformin hydrochloride tablets 15 mg/850 mg with food resulted in no change in overall exposure of pioglitazone. With metformin there was no change in AUC; however, mean peak serum concentration of metformin was decreased by 28% when administered with food. A delayed time to peak serum concentration was observed for both components (1.9 hours for pioglitazone and 0.8 hours for metformin) under fed conditions. These changes are not likely to be clinically significant.
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.Cmax, AUC, and trough serum concentrations (Cmin) for pioglitazone and M-III and M-IV, increased proportionally with administered doses of 15 mg and 30 mg per day.Following oral administration of pioglitazone, Tmax of pioglitazone was within two hours. Food delays the Tmaxto three to four hours, but does not alter the extent of absorption (AUC).
The absolute bioavailability of a 500 mg metformin tablet given under fasting conditions is approximately 50% to 60%. Studies using single oral doses of metformin tablets of 500 mg to 1500 mg, and 850 mg to 2550 mg, indicate that there is a lack of dose proportionality with increasing doses, which is due to decreased absorption rather than an alteration in elimination. At usual clinical doses and dosing schedules of metformin, steady-state plasma concentrations of metformin are reached within 24 to 48 hours and are generally < 1 mcg/mL. During controlled clinical trials, maximum metformin plasma levels did not exceed 5 mcg/mL, even at maximum doses.Food decreases the rate and extent of metformin absorption, as shown by a 40% lower mean Cmax, a 25% lower AUC, and a 35 minute prolongation of Tmax following administration of a single 850 mg tablet of metformin with food, compared to the same tablet strength administered fasting. The clinical relevance of these decreases is unknown.
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.
The Vd/F of metformin following single oral doses of 850 mg immediate-release metformin averaged 654 ± 358 L. Metformin is negligibly bound to plasma proteins. Metformin partitions into erythrocytes, most likely as a function of time.
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 Dosage and Administration (2.3) and Drug Interactions (7.1)]. Urinary 6ß-hydroxycortisol/cortisol ratios measured in patients treated with pioglitazone showed that pioglitazone is not a strong CYP3A4 enzyme inducer.
Intravenous single-dose studies in healthy subjects demonstrate that metformin is excreted unchanged in the urine and does not undergo hepatic metabolism (no metabolites have been identified in humans) nor biliary excretion.
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 clearance is approximately 3.5 times greater than creatinine clearance (CLcr) which indicates that tubular secretion is the major route of metformin elimination. Following oral administration, approximately 90% of the absorbed drug is eliminated via the renal route within the first 24 hours, with a plasma elimination t1/2 of approximately 6.2 hours. In blood, the elimination t1/2 is approximately 17.6 hours, suggesting that the erythrocyte mass may be a compartment of distribution.
INDICATION : Type 2 diabetes mellitus.
DOSAGE : As directed by the physician
SIDE EFFECTS : Diuretics, dizziness, diarrhoea, Weakness, weight loss.