Pioglitazone, Bladder Cancer and the Presumption of Innocence

BACKGROUND

Thiazolidinediones are potent exogenous agonists of PPAR-γ, which augment the effects of insulin to its cellular targets and mainly at the level of adipose tissue. Pioglitazone, the main thiazolidinedione in clinical practice, has shown cardiovascular and renal benefits in patients with type 2 diabetes, durable reduction of glycated hemoglobulin levels, important improvements of several components of the metabolic syndrome and beneficial effects of non-alcoholic fatty liver disease.

OBJECTIVE

Despite all of its established advantages, the controversy for an increased risk of developing bladder cancer, combined with the advent of newer drug classes that achieved major cardiorenal effects have significantly limited its use spreading a persistent shadow of doubt for its future role.

METHODS

Pubmed, Google and Scope databases have been thoroughly searched and relevant studies were selected.

RESULTS

This paper explores thoroughly both in vitro and in vivo (animal models and humans) studies that investigated the possible association of pioglitazone with bladder cancer.

CONCLUSION

Currently the association of pioglitazone with bladder cancer cannot be based on solid evidence. This evidence cannot justify its low clinical administration, especially in the present era of individualised treatment strategies. Definite clarification of this issue is imperative and urgently anticipated from future high quality and rigorous pharmacoepidemiologic research, keeping in mind its unique mechanism of action and its significant pleiotropic effects.

Impact of Hospitalization and Medication Switching on Post-discharge Adherence to Oral Anticoagulants in Patients With Atrial Fibrillation

BACKGROUND

Adherence to chronic medications remains poor in practice. There is limited evidence on how hospitalization affects post-discharge adherence to oral anticoagulants (OACs) in individuals with atrial fibrillation. The aim of this study was to examine the impact of hospitalization and medication switching on post-discharge adherence to OACs in the population with atrial fibrillation.

METHODS

A quasi-experimental pre-post observational study was conducted using United States commercial insurance health care claims from the 2009 to 2016 Optum database. Adults with atrial fibrillation taking OACs who had a random hospitalization occurring after the first observed OAC prescription fill and no other admission in the preceding and following 6 months were identified. OAC adherence was estimated by the proportion of days covered within 6 and 12 months before and after hospitalization. Difference-in-difference analysis was employed to compare the pre-hospitalization and post-hospitalization proportion of days covered, stratified by reasons for hospitalization (i.e., bleeding vs non-bleeding-related reasons) and adjusting for imbalanced baseline characteristics between groups. Change in adherence when the OAC was switched at discharge was also examined.

RESULTS

The 22,429 individuals who met study criteria were predominantly male (52.4%), white (77.2%), and older age (median 74 years). A clinically significant hemorrhage was the reason for 1029 (4.5%) of qualifying hospitalizations. After covariate adjustment, there was a reduction in the proportion of days covered after discharge, regardless of admission diagnosis (p<0.0001). The 6-month difference-in-difference analyses revealed that adherence was incrementally reduced by 3.2% (p=0.0003) in the bleeding group compared with the nonbleeding group, whereas switching from warfarin to a direct oral anticoagulant after hospitalization was associated with a smaller reduction by 3.4% in adherence (p=0.0342) compared with other switchers, regardless of the reason for hospitalization. The 12-month difference-in-difference analyses revealed similar results.

CONCLUSIONS

Hospitalization is temporally associated with a reduction in adherence to OACs, regardless of reason for hospitalization. More effective strategies are needed to improve OAC adherence, particularly during transition of care.

A survey of the FAERS database concerning the adverse event profiles of α1-adrenoreceptor blockers for lower urinary tract symptoms

PURPOSE

Current guidelines recommend α1-adrenoreceptor blockers (A1Bs) for treating lower urinary tract symptoms suggestive of benign prostatic hyperplasia, but their adverse effects can be problematic. In this study, reports submitted to the US Food and Drug Administration Adverse Event Reporting System (FAERS) between 1997 and 2011 were reviewed to assess the safety profiles of A1Bs.

METHODS

After deleting duplicated submissions and revising arbitrary drug names, reports involving A1Bs for male patients were analyzed. Data mining algorisms were used for the quantitative detection of signals, where a signal represents an association between a drug and an adverse event or a drug-associated adverse event, including the proportional reporting ratio, reporting odds ratio, information component given by a Bayesian confidence propagation neural network, and empirical Bayes geometric mean.

RESULTS

The total number of reports used was 1,260,182. Signal scores suggested the associations of alfuzosin, doxazosin, tamsulosin, and terazosin with dizziness/vertigo, orthostatic hypotension, erectile dysfunction, ejaculation dysfunction (EjD), thirst/dry mouth, and constipation; however, reports on naftopidil, silodosin, and urapidil were not enough to compare with the other 4 A1Bs. Signal scores for EjD were higher for tamsulosin, and those for dizziness/vertigo were lower for doxazosin than for the other 3 drugs.

CONCLUSIONS

Tamsulosin-associated EjD, which was found in clinical studies, was reproduced in this analysis with markedly higher signal scores, and these results strongly suggest the necessity of well-organized clinical studies on A1B-associated adverse events.