Comparison of pioglitazone with other antidiabetic drugs for associated incidence of liver failure: no evidence of increased risk of liver failure with pioglitazone

Antidiabetic agents in patients with hepatic impairment

Chronic liver disease (CLD) often coexists with type 2 diabetes mellitus, making diabetes management a challenge to the clinician. It is well known that liver is the major site of drug metabolism, and, therefore, its impairment affects hepatic metabolism of many antidiabetic agents. Furthermore, patients with CLD have serious comorbidities such as impaired renal function, hypoalbuminemia, lactic acidosis, hypoglycemia and malnutrition, making their treatment even more difficult. On the other hand, most of the antidiabetic agents, with the exception of insulin, need dosage titration due to alterations to their pharmacokinetics in patients with CLD. For well-established antidiabetic treatments, like metformin and sulfonylureas there are studies regarding their dosage chance in these patients. However, despite the growing problem of management of diabetes in patients with CLD the existing literature data, especially on newer antidiabetic agents, are limited and, furthermore, no direct guidelines exist. Therefore, in the present review article we try to summarize the existing literature data regarding management of diabetes in patients with CLD.

Evidence-based selection of training compounds for use in the mechanism-based integrated prediction of drug-induced liver injury in man

The current test systems employed by pharmaceutical industry are poorly predictive for drug-induced liver injury (DILI). The ‘MIP-DILI’ project addresses this situation by the development of innovative preclinical test systems which are both mechanism-based and of physiological, pharmacological and pathological relevance to DILI in humans. An iterative, tiered approach with respect to test compounds, test systems, bioanalysis and systems analysis is adopted to evaluate existing models and develop new models that can provide validated test systems with respect to the prediction of specific forms of DILI and further elucidation of mechanisms. An essential component of this effort is the choice of compound training set that will be used to inform refinement and/or development of new model systems that allow prediction based on knowledge of mechanisms, in a tiered fashion. In this review, we focus on the selection of MIP-DILI training compounds for mechanism-based evaluation of non-clinical prediction of DILI. The selected compounds address both hepatocellular and cholestatic DILI patterns in man, covering a broad range of pharmacologies and chemistries, and taking into account available data on potential DILI mechanisms (e.g. mitochondrial injury, reactive metabolites, biliary transport inhibition, and immune responses). Known mechanisms by which these compounds are believed to cause liver injury have been described, where many if not all drugs in this review appear to exhibit multiple toxicological mechanisms. Thus, the training compounds selection offered a valuable tool to profile DILI mechanisms and to interrogate existing and novel in vitro systems for the prediction of human DILI.

A multicenter assessment of single-cell models aligned to standard measures of cell health for prediction of acute hepatotoxicity

Assessing the potential of a new drug to cause drug-induced liver injury (DILI) is a challenge for the pharmaceutical industry. We therefore determined whether cell models currently used in safety assessment (HepG2, HepaRG, Upcyte and primary human hepatocytes in conjunction with basic but commonly used endpoints) are actually able to distinguish between novel chemical entities (NCEs) with respect to their potential to cause DILI. A panel of thirteen compounds (nine DILI implicated and four non-DILI implicated in man) were selected for our study, which was conducted, for the first time, across multiple laboratories. None of the cell models could distinguish faithfully between DILI and non-DILI compounds. Only when nominal in vitro concentrations were adjusted for in vivo exposure levels were primary human hepatocytes (PHH) found to be the most accurate cell model, closely followed by HepG2. From a practical perspective, this study revealed significant inter-laboratory variation in the response of PHH, HepG2 and Upcyte cells, but not HepaRG cells. This variation was also observed to be compound dependent. Interestingly, differences between donors (hepatocytes), clones (HepG2) and the effect of cryopreservation (HepaRG and hepatocytes) were less important than differences between the cell models per se. In summary, these results demonstrate that basic cell health endpoints will not predict hepatotoxic risk in simple hepatic cells in the absence of pharmacokinetic data and that a multicenter assessment of more sophisticated signals of molecular initiating events is required to determine whether these cells can be incorporated in early safety assessment.

A users' guide to understanding therapeutic substitutions

Therapeutic substitutions are common at the level of ministries of health, clinicians, and pharmacy dispensaries. Guidance in determining whether drugs offer similar risk-benefit profiles is limited. Those making decisions on therapeutic substitutions should be aware of potential biases that make differentiating therapeutic agents difficult. Readers should consider whether the biological mechanisms and doses are similar across agents, whether the evidence is sufficiently valid across agents, and whether the safety and therapeutic effects of each drug are similar. This article uses a problem-based format to address the biological mechanism, validity, and results of a scenario in which therapeutic substitutions may be considered.

Improvement of abnormal liver enzymes after rosiglitazone treatment in Chinese type 2 diabetes

Objectives:

Insulin resistance is one of the important underlying abnormalities of type 2 diabetes. The effect of thiazolidinedione on liver functions has been controversial in different studies. In this study, we evaluated the effect of rosiglitazone on liver enzymes in subjects with type 2 diabetes with and without abnormal liver function.

Materials and Methods:

Seventy-three patients with type 2 diabetes taking rosiglitazone 4 mg daily were enrolled in this 3-month study. Forty-two of them had normal liver function (NLF), and 31 had abnormal liver function (ABLF). Blood biochemistries were collected monthly during the treatment period.

Results:

At baseline, other than age and liver enzymes, there were no differences in body mass index, fasting plasma glucose, hemoglobin A1c (HbA1c), and lipid profiles between the NLF and ABLF groups. At the end of the treatment, HbA1c was lowered in both groups, but only significantly in the ABLF group (P = 0.027). More importantly, serum concentrations of both aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the ABLF group decreased significantly (AST: 57.8 ± 26.5 to 47.5 ± 20.2 U/L, P = 0.006; ALT 66.6 ± 35.0 to 51.9 ± 23.5 UL, P = 0.004), while in the NLF group, a similar change was not found.

Conclusion:

After 3-month rosiglitazone treatment in subjects with type 2 diabetes with mildly elevated liver enzymes, significant improvement in AST and ALT were observed. Our study provides some hints that rosiglitazone might not be contraindicated in subjects with diabetes with abnormal liver function as previously thought, but further well-designed studies are necessary to clarify this issue.

A review of methods used in assessing non-serious adverse drug events in observational studies among type 2 diabetes mellitus patients

Clinical drug trials are often conducted in selective patient populations, with relatively small numbers of patients, and a short duration of follow-up. Observational studies are therefore important for collecting additional information on adverse drug events (ADEs). Currently, there is no guidance regarding the methodology for measuring ADEs in such studies. Our aim was to evaluate whether the methodology used to assess non-serious ADEs in observational studies is adequate for detecting these ADEs, and for addressing limitations from clinical trials in patients with type 2 diabetes mellitus. We systematically searched MEDLINE and EMBASE for observational studies reporting non-serious ADEs (1999-2008). Methods to assess ADEs were classified as: 1) medical record review; 2) surveillance by health care professionals (HCP); 3) patient survey; 4) administrative data; 5) laboratory/clinical values; 6) not specified. We compared the range of ADEs identified, number and selection of patients included, and duration of follow-up. Out of 10,125 publications, 68 studies met our inclusion criteria. The most common methods were based on laboratory/clinical values (n = 25) and medical record review (n = 18). Solicited surveillance by HCP (n = 17) revealed the largest diversity of ADEs. Patient surveys (n = 15) focused mostly on hypoglycaemia and gastrointestinal ADEs, laboratory values based studies on hepatic and metabolic ADEs, and administrative database studies (n = 5) on cardiovascular ADEs. Four studies presented ADEs that were identified with the use of more than one method. The patient population was restricted to a lower risk population in 19% of the studies. Less than one third of the studies exceeded pre-approval regulatory requirements for sample size and duration of follow-up. We conclude that the current assessment of ADEs is hampered by the choice of methods. Many observational studies rely on methods that are inadequate for identifying all possible ADEs. Patient-reported outcomes and combinations of methods are underutilized. Furthermore, while observational studies often include unselective patient populations, many do not adequately address other limitations of pre-approval trials. This implies that these studies will not provide sufficient information about ADEs to clinicians and patients. Better protocols are needed on how to assess adverse drug events not only in clinical trials but also in observational studies.

Drug safety of rosiglitazone and pioglitazone in France: a study using the French PharmacoVigilance database

Background

Thiazolidinediones (TZDs), rosiglitazone (RGZ) and pioglitazone (PGZ) are widely used as hypoglycemic drugs in patients with type 2 diabetes mellitus. The aim of our study was to investigate the profile of adverse drug reactions (ADRs) related to TZDs and to investigate potential risk factors of these ADRs.

Methods

Type 2 diabetic patients were identified from the French Database of PharmacoVigilance (FPVD) between 2002 and 2006. We investigated ADR related to TZD, focusing on 4 ADR: edema, heart failure, myocardial infarction and hepatitis corresponding to specific WHO-ART terms.

Results

Among a total of 99,284 adult patients in the FPVD, 2295 reports concerned type 2 diabetic patients (2.3% of the whole database), with 161 (7%) exposed to TZDs. The frequency of edema and cardiac failure was significantly higher with TZDs than in other patients (18% and 7.4% versus 0.8% and 0.1% respectively, p < 0.001) whereas the frequency of hepatitis was similar (5.9% versus 4%, NS). A multiple logistic regression model taking into account potential confounding factors (age, gender, drug exposure and co-morbidities) found that TZD exposure remained associated with heart failure and edema, but not with hepatitis or myocardial infarction.

Conclusions

Thiazolidinediones exposure is associated with an increased risk of edema and heart failure in patients with type 2 diabetes even when recommendations for use are respected. In contrast, the risk of hepatic reactions and myocardial infarction with this class of drugs seems to be similar to other hypoglycemic agents.

Thiazolidinedione use and ulcerative colitis-related flares: an exploratory analysis of administrative data

BACKGROUND

Recent animal studies and clinical trials suggest that thiazolidinediones, a class of oral antidiabetic agents, are efficacious in reducing inflammation, yet no studies have evaluated their effectiveness in preventing flares. We examined the association between thiazolidinedione use and ulcerative colitis (UC)-related flares.

METHODS

We conducted a retrospective cohort study using administrative data from 87 health plans across 33 states. Individuals with both UC and diabetes were identified using administrative definitions. Exposure to thiazolidinediones or other oral antidiabetic agents was ascertained through outpatient pharmacy claims. The primary outcome was occurrence of a UC flare defined by: 1) a new prescription for oral steroids, infliximab, or oral/rectal salicylates, or 2) a claim for colectomy. Secondary analyses analyzed outcomes separately. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression after matching each thiazolidinedione user to a comparable oral antidiabetic user on propensity score.

RESULTS

This study included 142 thiazolidinedione and 468 other oral antidiabetic users with a mean follow-up of 7.3 and 6.2 months, respectively. Thiazolidinedione use was not associated with UC-related flares as measured by the composite outcome (HR = 1.05, 95% CI: 0.66, 1.68). However, thiazolidinedione use was associated with a nonsignificant reduction in risk of oral steroid use when analyzed as a separate outcome (HR = 0.53, 95% CI: 0.20, 1.44).

CONCLUSIONS

Thiazolidinediones do not provide any benefit over other oral antidiabetics in preventing UC-related flares as measured by our primary composite outcome. However, thiazolidinedione use may reduce the risk of more significant disease flares requiring oral steroid treatment.

Case series of liver failure associated with rosiglitazone and pioglitazone

PURPOSE

The thiazolidinedione drugs rosiglitazone and pioglitazone are not widely known to be hepatotoxic. We evaluated the FDA Adverse Event Reporting System (AERS) to determine the number of reported cases of liver failure associated with rosiglitazone and pioglitazone between 1997 and 2006, and described their clinical characteristics.

METHODS

Adverse event reports spontaneously submitted to the FDA AERS from 1997 to 2006 were examined. Liver failure associated with rosiglitazone or pioglitazone was defined as liver injury accompanied by hepatic encephalopathy, liver transplantation, placement on a liver transplant list, or death in which all other likely etiologies were excluded. Using prescribing data, the number of reported cases of liver failure per million patient-years of exposure was calculated for each drug.

RESULTS

Twenty-one cases met our case definition. Clinical characteristics, outcomes, and pathologic data were similar between cases of liver failure associated with rosiglitazone and with pioglitazone. The median duration of therapy was 9 weeks and 85% of cases were acute, defined as symptom onset to liver failure in less than 26 weeks. The case-fatality rate was 81% (17/21), and only 14% (3/21) spontaneously recovered. Accounting for underreporting, the number needed to harm (NNH) for each case of liver failure was 44 000 patient-years of exposure for rosiglitazone and 52 000 patient-years of exposure for pioglitazone.

CONCLUSIONS

This is the largest case series of liver failure associated with rosiglitazone or pioglitazone reported to date, strengthening the evidence that these drugs can cause severe hepatotoxicity.

Differential effects of pioglitazone on metabolic parameters in newly diagnosed, drug-naïve Japanese patients with type 2 diabetes with or without metabolic syndrome

OBJECTIVE

The aim of this study was to evaluate the efficacy of pioglitazone on metabolic parameters in drug-naïve Japanese type 2 diabetic patients with (Diabetes Mellitus Metabolic Syndrome [DMMS] group, n = 36) and without (Diabetes Mellitus non-Metabolic Sundrome [DMNMS] group, n = 36) metabolic syndrome.

PATIENTS AND METHODS

The patients received monotherapy of 15-30 mg/day pioglitazone for 3 months. The baseline levels of metabolic parameters were compared with the levels after 3 months.

RESULTS

At baseline, the two groups showed no significant difference in HbA1c (10.05 vs. 9.81%, n.s.) or systolic blood pressure (134.5 vs. 133.0 mmHg, n.s.), but had significant differences in diastolic blood pressure (84.7 vs. 78.9 mmHg, p < 0.05), insulin (14.96 vs. 7.09 microU/mL, p < 0.001), homeostasis model assessment insulin resistance index (HOMA-R) (8.49 vs. 3.96, p < 0.001), triglyceride (TG) (231.4 vs. 131.5 mg/dL, p < 0.0005), high-density lipoprotein (HDL)-C (46.6 vs. 56.1 mg/dL, p < 0.005), body weight (BW) (77.97 vs. 62.52 kg, p < 0.001), and body mass index (BMI) (28.14 vs. 22.86, p < 0.00001). In the DMMS group, significant changes of HbA1c (from 10.05 to 8.01%, p < 0.00001), insulin (-22.7%, p < 0.05), HOMA-R (-48.9%, p < 0.0002), TG (-20.8 %, p < 0.05), HDL-C (+12.0%, p < 0.00001), BW (+1.0 kg/+1.3%, p < 0.05), and BMI (+1.4%, p < 0.02) were observed after 3 months. In the DMNMS group, the reduction of HbA1c (from 9.81 to 8.33%, p < 0.00001) was similar to that in the DMMS group, but the changes of insulin (-4.7%, n.s.), HOMA-R (-15.6%, n.s.), and TG (-12.9%, n.s.) were smaller and not significant. Significant increases of HDL-C (+9.2%, p < 0.02), BW (+0.64 kg/+1.0%, p < 0.05), and BMI (+1.0%, p < 0.02) were observed, but these changes were also smaller than the respective changes in the DMMS group. Based on the change of each parameter relative to its baseline value, significant intergroup differences were found for TG, insulin, or HOMA-R, whereas no such differences were observed for HDL-C, BW, and BMI. No subjects showed any clinically significant adverse events.

CONCLUSIONS

These results suggest that the glucose-lowering effect of pioglitazone is comparable in patients with type 2 diabetes with or without metabolic syndrome, but that the drug has different effects on nonglycemic parameters including TG, insulin and HOMA-R in the two groups of patients.

Liver safety in patients with type 2 diabetes treated with pioglitazone: results from a 3-year, randomized, comparator-controlled study in the US

BACKGROUND/AIMS

Non-alcoholic fatty liver disease (NAFLD), the major hepatic manifestation of type 2 diabetes mellitus, is the most common liver disease in the US. Thiazolidinediones, a commonly used drug class for the treatment of type 2 diabetes, have emerged as a potentially useful treatment for NAFLD. There are, however, lingering concerns about their potential toxicity as well as emerging concerns about how to monitor for and assess hepatotoxicity. We conducted a randomized, long-term, double-blind, hepatic safety study at 171 centres in the US in which 2097 patients with type 2 diabetes received either pioglitazone or glibenclamide (glyburide).

METHODS

Patients were randomized to receive either pioglitazone (15-45 mg once daily) or glibenclamide (5-15 mg once daily) for 3 years. The primary objective was to evaluate drug-induced liver injury manifested by liver enzyme elevations, measured every 8 weeks for the first year and every 12 weeks thereafter. The primary endpoint was a confirmed ALT greater than three times the upper limit of normal (>3 x ULN) with a secondary endpoint of 8 x ULN.

MAIN RESULTS

The intent-to-treat population included 1051 pioglitazone-treated and 1046 glibenclamide-treated patients; of these, 411 pioglitazone patients and 413 glibenclamide patients completed the study. The incidence of hepatocellular injury was 0 with pioglitazone and 4 (0.38%) with glibenclamide (p = 0.0617). Analyses of the secondary endpoints revealed no ALT >8 x ULN for pioglitazone versus 1 with glibenclamide (p = 0.4988); no ALT >3 x ULN + total bilirubin 2 x ULN with pioglitazone versus 1 with glibenclamide (p = 0.4988); and fewer ALT >3 x ULN single elevations with pioglitazone (n = 3) than with glibenclamide (n = 9; p = 0.0907). Significantly (p < or = 0.05) fewer cases of ALT >1.5 x ULN, aspartate aminotransferase >1.5 x ULN and gamma-glutamyl transpeptidase >1.5 x ULN were seen with pioglitazone compared with glibenclamide. No case of hepatic dysfunction or hepatic failure was reported in either treatment group; two cases of hepatic cirrhosis with glibenclamide were reported.

CONCLUSION

This study demonstrates an hepatic safety profile of pioglitazone similar to that of glibenclamide in long-term use in patients with poorly controlled type 2 diabetes. Trial registration number (clinicaltrials.gov): NCT00494312.

Safety and tolerability of pioglitazone in high-risk patients with type 2 diabetes: an overview of data from PROactive

People with type 2 diabetes mellitus have an excess risk of macrovascular disease and a poorer prognosis. PROactive (PROspective pioglitAzone Clinical Trial In macroVascular Events) was a landmark study of secondary cardiovascular disease (CVD) prevention in type 2 diabetes that suggested a beneficial effect of pioglitazone therapy on macrovascular outcomes. Previous studies have already shown that pioglitazone has a good safety and tolerability profile in people with type 2 diabetes, but PROactive provided an opportunity to assess tolerability and safety associated with long-term exposure in a vulnerable subpopulation at very high cardiovascular risk. This review discusses all the key safety and tolerability characteristics associated with pioglitazone therapy in PROactive. As in previous studies, pioglitazone was associated with typical, but manageable, increases in oedema (26.4% vs 15.1% for placebo) and weight gain (mean change of +3.8 kg vs -0.6 kg for placebo). Increased hypoglycaemia with pioglitazone was consistent with improved glycaemic control. Despite more reports of serious heart failure in the pioglitazone group (5.7% vs 4.1% for placebo), there was a proportional improvement in macrovascular outcomes among patients developing heart failure, and absolute rates of macrovascular events and mortality were similar to those in the placebo group. Liver function tests confirmed the hepatic safety of pioglitazone with long-term use and revealed a tendency to improved hepatic function, which may reflect reductions in liver fat. The comparative incidence of malignancies was similar; however, more cases of bladder neoplasm (14 vs 5) and fewer cases of breast cancer (3 vs 11) were observed in the pioglitazone versus placebo arms of the study. A higher rate of bone fractures observed among pioglitazone-treated female patients (5.1% vs 2.5%) warrants further investigation. Overall, safety and tolerability was predictable, and adverse events were not treatment limiting. These results suggest that any beneficial effects of pioglitazone on macrovascular outcomes are accompanied by good long-term tolerability in this population of very high-risk patients with type 2 diabetes and established CVD.

Pioglitazone for type 2 diabetes mellitus

BACKGROUND

Diabetes has long been recognised as a strong, independent risk factor for cardiovascular disease, a problem which accounts for approximately 70% of all mortality in people with diabetes. Prospective studies show that compared to their non-diabetic counterparts, the relative risk of cardiovascular mortality for men with diabetes is two to three and for women with diabetes is three to four. The two biggest trials in type 2 diabetes, the United Kingdom Prospective Diabetes Study (UKPDS) and the University Group Diabetes Program (UGDP) study did not reveal a reduction of cardiovascular endpoints through improved metabolic control. Theoretical benefits of the newer peroxisome proliferator activated receptor gamma (PPAR-gamma) activators like pioglitazone on endothelial function and cardiovascular risk factors might result in fewer macrovascular disease events in people with type 2 diabetes mellitus.

OBJECTIVES

To assess the effects of pioglitazone in the treatment of type 2 diabetes.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE and The Cochrane Library. The last search was conducted in August 2006.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials in adult people with type 2 diabetes mellitus and had a trial duration of at least 24 weeks.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Pooling of studies by means of random-effects meta-analysis could be performed for adverse events only.

MAIN RESULTS

Twenty-two trials which randomised approximately 6200 people to pioglitazone treatment were identified. Longest duration of therapy was 34.5 months. Published studies of at least 24 weeks pioglitazone treatment in people with type 2 diabetes mellitus did not provide convincing evidence that patient-oriented outcomes like mortality, morbidity, adverse effects, costs and health-related quality of life are positively influenced by this compound. Metabolic control measured by glycosylated haemoglobin A1c (HbA1c) as a surrogate endpoint did not demonstrate clinically relevant differences to other oral antidiabetic drugs. Occurrence of oedema was significantly raised. The results of the single trial with relevant clinical endpoints (Prospective Pioglitazone Clinical Trial In Macrovascular Events--PROactive study) have to be regarded as hypothesis-generating and need confirmation.

AUTHORS' CONCLUSIONS

Until new evidence becomes available, the benefit-risk ratio of pioglitazone remains unclear. Different therapeutic indications for pioglitazone of the two big U.S. and European drug agencies should be clarified to reduce uncertainties amongst patients and physicians.

Effect of pioglitazone on urinary liver-type fatty acid-binding protein concentrations in diabetes patients with microalbuminuria

BACKGROUND

Urinary liver-type fatty acid-binding protein (L-FABP) is a useful marker for renal tubulointerstitial injury. Pioglitazone is reported to be effective in early diabetic nephropathy. The aim of the present study was to determine whether pioglitazone affects urinary L-FABP levels in diabetic nephropathy patients with microalbuminuria.

METHODS

Sixty-eight patients with type 2 diabetes and microalbuminuria were randomized to a 12-month treatment with pioglitazone (30 mg/d, n = 17), glibenclamide (5 mg/d, n = 18), voglibose (0.6 mg/d, n = 17), or nateglinide (270 mg/d, n = 16). Pre- and posttreatment urinary albumin excretion (UAE) and urinary L-FABP concentrations were compared between the four treatment groups and 40 age-matched healthy subjects.

RESULTS

Pretreatment UAE and urinary L-FABP levels differed little between the four groups. UAE and urinary L-FABP levels were significantly greater in the diabetes patients than in the healthy subjects (UAE: p < 0.001; L-FABP: p < 0.01). After 6 and 12 months, UAE and urinary L-FABP were significantly lower in the pioglitazone treatment group than in the other treatment groups (UAE: 6 months, p < 0.01 and 12 months, p < 0.001; L-FABP: 6 months, p < 0.05 and 12 months, p < 0.01).

CONCLUSIONS

Pioglitazone, but not glibenclamide, voglibose, or nateglinide, appears to be effective in reducing UAE and the urinary L-FABP level, suggesting that pioglitazone has a specific role in ameliorating both glomerular and tubulointerstitial lesions associated with early diabetic nephropathy.