Optimal study design for pioglitazone in septic pediatric patients

Low-Dose Pioglitazone does not Increase ROS Production in Chronic Granulomatous Disease Patients with Severe Infection

PURPOSE

We sought to further investigate the efficacy and safety of pioglitazone for chronic granulomatous disease (CGD) patients with severe infection.

METHODS

CGD patients with severe infection were enrolled and treated with pioglitazone for 90 days. The degree of improvement in infection and the changes of dihydrorhodamine-123 (DHR) were used to evaluate the efficacy of pioglitazone. The adverse reaction of pioglitazone was also investigated.

RESULTS

We planned to enroll 30 patients at first in the study. However, the study was terminated due to negative results from all 3 enrolled patients. The 3 patients were diagnosed with CGD by clinical characteristics, DHR analysis, and genetics analysis. Mutations were CYBB (c.177C>A; p.C59X) in P1, CYBB (c.1498G>T; p.D500Y) in P2, and NCF2 (c.137T>G; p.M46R) in P3, respectively. The age of onset of the 3 patients was within 2 years after birth. The most common sites of infection were lung, lymph node, skin, and soft tissue, which were experienced in all 3 patients. The age of administration with pioglitazone was 5.2 years, 16 years and 11.1 years, respectively. The 3 patients experienced no improvement in severity of infection and stimulation index of the DHR did not also improve after receiving pioglitazone 10, 45 and 90 days, respectively. No drug-related adverse reaction was found during the period of pioglitazone.

CONCLUSIONS

Low dose of pioglitazone did not improve the severity of infection and production of ROS in CGD patients with severe infection.

Pioglitazone reduces cold-induced brown fat glucose uptake despite induction of browning in cultured human adipocytes: a randomised, controlled trial in humans

AIMS/HYPOTHESIS

Increasing brown adipose tissue (BAT) activity is a possible therapeutic strategy to increase energy expenditure and glucose and lipid clearance to ameliorate obesity and associated comorbidities. The thiazolidinedione (TZD) class of glucose-lowering drugs increase BAT browning in preclinical experimental models but whether these actions extend to humans in vivo is unknown. The aim of this study was to determine the effect of pioglitazone treatment on adipocyte browning and adaptive thermogenesis in humans.

METHODS

We first examined whether pioglitazone treatment of cultured human primary subacromioclavicular-derived adipocytes induced browning. Then, in a blinded, placebo-controlled, parallel trial, conducted within the Baker Institute clinical research laboratories, 14 lean male participants who were free of cardiometabolic disease were randomised to receive either placebo (lactose; n = 7, age 22 ± 1 years) or pioglitazone (45 mg/day, n = 7, age 21 ± 1 years) for 28 days. Participants were allocated to treatments by Alfred Hospital staff independent from the study via electronic generation of a random number sequence. Researchers conducting trials and analysing data were blind to treatment allocation. The change in cold-stimulated BAT activity, assessed before and after the intervention by [¹⁸F]fluorodeoxyglucose uptake via positron emission tomography/computed tomography in upper thoracic and cervical adipose tissue, was the primary outcome measure. Energy expenditure, cardiovascular responses, core temperature, blood metabolites and hormones were measured in response to acute cold exposure along with body composition before and after the intervention.

RESULTS

Pioglitazone significantly increased in vitro browning and adipogenesis of adipocytes. In the clinical trial, cold-induced BAT maximum standardised uptake value was significantly reduced after pioglitazone compared with placebo (-57 ± 6% vs -12 ± 18%, respectively; p < 0.05). BAT total glucose uptake followed a similar but non-significant trend (-50 ± 10% vs -6 ± 24%, respectively; p = 0.097). Pioglitazone increased total and lean body mass compared with placebo (p < 0.05). No other changes between groups were detected.

CONCLUSIONS/INTERPRETATION

The disparity in the actions of pioglitazone on BAT between preclinical experimental models and our in vivo human trial highlight the imperative to conduct human proof-of-concept studies as early as possible in BAT research programmes aimed at therapeutic development. Our clinical trial findings suggest that reduced BAT activity may contribute to weight gain associated with pioglitazone and other TZDs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02236962 FUNDING: This work was supported by the Diabetes Australia Research Program and OIS scheme from the Victorian State Government.

Synergistic protection against acute flurothyl-induced seizures by adjuvant treatment of the ketogenic diet with the type 2 diabetes drug pioglitazone

OBJECTIVE

We have previously found that the transcription factor peroxisome proliferator-activated receptor γ (PPARγ) contributes to the mechanism of action of the ketogenic diet (KD), an established treatment for pediatric refractory epilepsy. We have found that the KD increases brain PPARγ and that inhibition or genetic loss of PPARγ prevents the antiseizure effects of the KD on (1) acutely induced seizures in nonepileptic mice and (2) spontaneous recurrent seizures in epileptic mice. Here, we tested the hypothesis that adjuvant treatment of KD-treated mice with a PPARγ agonist, pioglitazone, would result in an additive effect.

METHODS

Acute seizures were induced in three groups of C57Bl/6 mice by inhalation exposure to flurothyl gas. In Group 1, mice were weaned onto either a standard diet or KD comprised of a fat:carbohydrate/protein ratio of either 6:1, 3:1, or 1:1 for 2 weeks. In Group 2, vehicle or pioglitazone (0.1, 1, 10, 80 mg/kg) was administered 4 h prior to flurothyl exposure. In Group 3, vehicle or increasing doses of pioglitazone were administered to KD-treated mice 4 h prior to flurothyl exposure. Latency times to clonic seizures and generalized tonic-clonic (GTC) seizures were recorded, and isobolographic analysis was used to determine combinatorial interactions.

RESULTS

Neither KD treatment nor pioglitazone alone or in combination affected clonic seizures. However, the latency to GTC seizures was dose-dependently and significantly increased by both KD (~57%, p < 0.05) and pioglitazone (~28%, p < 0.05). Coadministration of an ineffective 1:1 KD and pioglitazone resulted in ~47-55% (p < 0.05) increase in latency to GTC. Isobolographic analysis indicated a synergistic interaction of the KD and pioglitazone.

SIGNIFICANCE

These results suggest coadministration may enable reduction of the KD ratio without loss of seizure protection. Such adjuvant treatment could improve quality of life and limit adverse effects of a classic KD or high-dose pioglitazone.

Study on integrated pharmacokinetics of gardenia acid and geniposide: time-antioxidant efficacy after oral administration of Huanglian-Zhizi couplet medicine from Huang-Lian-Jie-Du-Tang in MCAO rats

Huanglian-Zhizi couplet medicine comes from classical prescription Huang-Lian-Jie-Du-Tang (HLJDT), which has been proven by previous researches to be an effective compound for cerebral ischemia. This paper explores the integrated pharmacokinetics of gardenia acid and geniposide-time-antioxidant efficacy after the oral administration of Huanglian-Zhizi couplet medicine from HLJDT in rats with middle cerebral artery occlusion (MCAO). To investigate the differences in pharmacokinetics and antioxidant effect of Huanglian-Zhizi and HLJDT in MCAO rats, which have been scarcely reported, an oral dose, 24 crud drug g/kg, of Huanglian-Zhizi and 40 crud drug/kg of HLJDT were administered in two groups of normal rats and two groups of Sprague-Dawley (SD) MCAO rats, respectively. At different time points, concentrations of gardenia acid and geniposide were determined by high performance liquid chromatography (HPLC), and levels of superoxide dismutase (SOD) were calculated by ELIASA. Pharmacokinetic parameters including AUC, MRT, t1/2, T max , C max were estimated by statistical moment analysis using a data analysis system (DAS) 2.0. An AUC based on weighting approach was used for integrating gardenia acid and geniposide. Finally, the concentration-time efficacy profiles were obtained. The integrated pharmacokinetics profiles of index components could reveal the pharmacokinetics behavior of Huanglian-Zhizi and HLJDT, corresponding to the antioxidant efficacy.

Exploratory Pharmacokinetics of Geniposide in Rat Model of Cerebral Ischemia Orally Administered with or without Baicalin and/or Berberine

Huang-Lian-Jie-Du-Tang (HLJDT), a classical Chinese prescription, has been clinically employed to treat cerebral ischemia for thousands of years. Geniposide is the major active ingredient in HLJDT. The aim is to investigate the comparative evaluations on pharmacokinetics of geniposide in MCAO rats in pure geniposide, geniposide : berberine, and geniposide : berberine : baicalin. Obviously, the proportions of geniposide : berberine, geniposide : baicalin, and geniposide : berberine : baicalin were determined according to HLJDT. In our study, the cerebral ischemia model was reproduced by suture method in rats. The MCAO rats were randomly assigned to four therapy groups and orally administered with different prescription proportions of pure geniposide, geniposide : berberine, geniposide : baicalin, and geniposide : berberine : baicalin, respectively. The concentrations of geniposide in rat serum were determined using HPLC, and main pharmacokinetic parameters were investigated. The results indicated that the pharmacokinetics of geniposide in rat serum was nonlinear and there were significant differences between different groups. Berberine might hardly affect the absorption of geniposide, and baicalin could increase the absorption ability of geniposide. Meanwhile, berberine could decrease the absorption increase of baicalin on geniposide.

Optimal designs for composed models in pharmacokinetic-pharmacodynamic experiments

We consider two frequently used PK/PD models and provide closed form descriptions of locally optimal designs for estimating individual parameters. In a novel way, we use these optimal designs and construct locally standardized maximin optimal designs for estimating any subset of the model parameters of interest. We do this by maximizing the minimal efficiency of the estimates across all relevant parameters so that these optimal designs are less dependent on the individual parameter or parameters of interest. Additionally, robust designs are proposed to further reduce the dependence on the nominal values of the parameters. We compare efficiencies of our proposed optimal designs with locally optimal designs and designs used in four real studies from the literature and show that our proposed designs provide advantages over those used in practice.