Fibrates et risques thrombo-emboliques veineux : étude cas/non-cas dans la base nationale de pharmacovigilance

Interest of pharmacoepidemiology for pharmacodynamics and analysis of the mechanism of action of drugs

Pharmacology is often divided in separate branches, such as molecular and cellular pharmacology, pharmacokinetics, pharmacodynamics, experimental and/or preclinical pharmacology, clinical pharmacology (and therapeutics), pharmacogenetics, pharmacogenomics, pharmacovigilance, pharmacoepidemiology, pharmacoeconomics… This enumeration gives a global picture of different scientific areas, which are however dealing with the same question. Another mindset should be a global interactive and continuous approach, which could be designed as "human pharmacology". An original and attractive way to illustrate this continuous approach is to combine pharmacodynamics and pharmacovigilance and/or pharmacoepidemiologic data. Coupling disproportionality analyses in pharmacovigilance databases or computerized health databases, with pharmacological characteristics of drugs (receptor affinity, for example) allows investigating in humans, the mechanism of adverse drug reactions. Examples of such analyses investigating the risk of movement disorders, diabetes related to psychoactive drugs, or the risk of adverse cardiac outcomes with different drugs (classical drugs or protein kinase inhibitors) are given. The increasing number of research works investigating this topic underlines the importance of this relatively new approach, which gives significant inputs for the better knowledge of drug safety.

Association between venous thromboembolism events and fibrates: A comparative study

AIM

Previous studies highlighted a significant association between fibrates and venous thromboembolism (VTE) events in dyslipidemia diabetic patients. Studies in non-diabetic patients are divergent. The present study investigated the association between VTE events and fibrates in diabetic and non-diabetic patients.

METHODS

Two approaches were used: (1) a disproportionality analysis using the World health organization pharmacovigilance database VigiBase^® was used to evaluate the reporting odds-ratio (ROR) of fibrates for VTE events. Clinical and demographic characterizations of patients with fibrates-related VTE reports are described; (2) a case control-study was performed using the Caen university hospital medical information database between January 2008 and December 2012. Cases were dyslipidemia patients who were hospitalized for VTE without an evident provoking factor. Up to four controls per case were selected in dyslipidemia patients hospitalized for a non-VTE event. Controls were matched to cases by age, gender, date of hospitalization, diabetes, chronic kidney disease and hospitalization department. A multivariate conditional logistic regression was performed.

RESULTS

Disproportionality analysis: a total of 946 notifications were identified in VigiBase^® (32.9% of diabetic patients). Fibrates were significantly associated with an increased report of VTE (ROR 1.14, CI 1.07-1.22). Case-control study: a total of 163 cases (21.5% of diabetic patients) and 514 matched controls were recruited. Fibrates were significantly associated with a higher risk of VTE events that required hospitalization in multivariate analysis (odds-ratio (OR) 3.67, CI 1.82-7.37, P=0.0003). The association was only significant for fenofibrate in both approaches.

CONCLUSION

Fenofibrate was associated with a higher incidence of VTE events in diabetic and non-diabetic patients.

What is pharmacoepidemiology? Definition, methods, interest and clinical applications

Clinical evaluation of drugs before approval is based on the experimental design of clinical trial with randomization of drug exposure. Unfortunately, conclusions of clinical trials are necessarily limited to patients included into the trials. It is thus necessary to compare these experimental data coming from clinical trials with the real use of drugs in clinical practice. Pharmacoepidemiology is the study of interactions between drugs and human populations, investigating, in real conditions of life, benefits, risks and use of drugs. Pharmacoepidemiology applies to drugs the methods and/or reasoning of both pharmacology and epidemiology. The development of pharmacoepidemiology should improve the "rational drug use".