Public health impact of low-dose aspirin on colorectal cancer, cardiovascular disease and safety in the UK - Results from micro-simulation model.

BACKGROUND: Low-dose aspirin therapy reduces the risk of cardiovascular disease and may have a positive effect on the prevention of colorectal cancer. We evaluated the population-level expected effect of regular low-dose aspirin use on cardiovascular disease (CVD), colorectal cancer (CRC), gastrointestinal bleeding, symptomatic peptic ulcers, and intracranial hemorrhage, using a microsimulation study design. METHODS: We used individual-level state transition modeling to assess the impact of aspirin in populations aged 50-59 or 60-69 years old indicated for low-dose aspirin usage for primary or secondary CVD prevention. Model parameters were based on data from governmental agencies from the UK or recent publications. RESULTS: In the 50-59 years cohort, a decrease in incidence rates (IRs per 100 000 person years) of non-fatal CVD (-203 and -794) and fatal CVD (-97 and-381) was reported in the primary and secondary CVD prevention setting, respectively. The IR reduction of CRC (-96 and -93) was similar for primary and secondary CVD prevention. The IR increase of non-fatal (116 and 119) and fatal safety events (6 and 6) was similar for primary and secondary CVD prevention. Similar results were obtained for the 60-69 years cohort. CONCLUSIONS: The decrease in fatal CVD and CRC events was larger than the increase in fatal safety events and this difference was more pronounced when low-dose aspirin was used for secondary compared to primary CVD prevention. These results provide a comprehensive image of the expected effect of regular low-dose aspirin therapy in a UK population indicated to use aspirin for CVD prevention.

Benefits of combining change-point analysis with disproportionality analysis in pharmacovigilance signal detection.

BACKGROUND: Change-point analysis (CPA) is a powerful method to analyse pharmacovigilance data but it has never been used on the disproportionality metric. OBJECTIVES: To optimize signal detection investigating the interest of time-series analysis in pharmacovigilance and the benefits of combining CPA with the proportional reporting ratio (PRR). METHODS: We investigated the couple benfluorex and aortic valve incompetence (AVI) using the French National Pharmacovigilance and EudraVigilance databases: CPA was applied on monthly counts of reports and the lower bound of monthly computed PRR (PRR-). We stated a CPA hypothesis that the substance-event combination is more likely to be a signal when the 2 following criteria are fulfilled: PRR- is greater than 1 with at least 5 cases, and CPA method detects at least 2 successive change points of PRR- which made consecutively increasing segments. We tested this hypothesis by 95 test cases identified from a drug safety reference set and 2 validated signals from EudraVigilance database: CPA was applied on PRR-. RESULTS: For benfluorex and AVI, change points detected by CPA on PRR- were more meaningful compared with monthly counts of reports: More change points detected and detected earlier. In the reference set, 14 positive controls satisfied CPA hypothesis, 6 positive controls only met first requirements, 3 negative controls only met first requirement, and 2 validated signals satisfied CPA hypothesis. CONCLUSIONS: The combination of CPA and PRR represents a significant advantage in detecting earlier signals and reducing false-positive signals. This approach should be confirmed in further studies.

[Fibrates and risk of venous thromboembolism: Case/no-case study in French pharmacovigilance database]. / Fibrates et risques thrombo-emboliques veineux : étude cas/non-cas dans la base nationale de pharmacovigilance.

INTRODUCTION: Several studies have investigated the occurrence of venous thromboembolic events (phlebitis and pulmonary embolism) [VTE] and fibrates. Fibrates could be associated with VTE although published data are contradictory. The objective of this study is to confirm the link between VTE and fibrates. MATERIALS AND METHODS: Retrospective disproportionality analysis (case/non-case method) from observations recorded consecutively in the French pharmacovigilance database between 1985 and 2016. Cases were defined as embolic and thrombotic events, thrombophlebitis; Non-cases were other adverse events reported over the same period. We measured the disproportionality of exposure to each fibrate among cases and no-cases. The analysis was validated with a positive control (drospirenone) and a negative control (paracetamol). RESULTS: We compared 19,436 cases (including 161 mentioning fibrates) to 563,310 non-cases (including 3228 fibrates). Reports of VTE were significantly associated with fenofibrate (ROR=1.83; 95% CI=[1.53; 2.2]) but not with other fibrates: bézafibrate (ROR=0.44; 95% CI=[0.2; 0.99]), ciprofibrate (ROR=1.15; 95% CI=[0.76; 1.73]) and gemfibrozil (ROR=0.91; 95% CI=[0.45; 1.84]). CONCLUSION: With this study, we confirm the link between VTE and fenofibrate. It is therefore advisable to remain cautious when prescribing fenofibrate, in particular in case of past history of VTE and to declare systematically any venous thromboembolic adverse events observed with these drugs.

Reports of sexual disorders related to serotonin reuptake inhibitors in the French pharmacovigilance database: an example of underreporting.

BACKGROUND: Depressive disorders and use of antidepressants are associated with adverse effects on sexual function. In pharmacoepidemiological studies, sexual disorders are reported by more than 50 % of patients taking serotonin reuptake inhibitors (SRIs). OBJECTIVE: The aim of this study was to determine the reporting rate of sexual disorders in association with SRIs, and to investigate the association between reported cases and the use of SRIs. METHODS: All cases of adverse drug reactions (ADRs) involving sexual disorders, spontaneously reported to the French Pharmacovigilance Database from 1 January 1985 to December 2009, were reviewed. Cases of sexual disorders in SRI users were described. We calculated the rate of reported sexual disorders as a percentage of the total ADRs reported for each drug. The association between reported cases and the use of SRIs was assessed using reporting odds ratios (ROR) with 95 % confidence intervals (CIs). RESULTS: A total of 11,863 ADRs in association with SRIs were collected, of which 98 (0.83 %) were spontaneous reports of sexual disorders. Subjects were, on average, 45.0 ± 10.6 years of age and mainly male. Sexual disorders were associated with the use of SRI antidepressants (ROR 4.47; 95 % CI 3.61-5.53), milnacipran (ROR 11.72; 95 % CI 5.79-23.72), fluvoxamine (ROR 6.91; 95 % CI 3.79-12.58), paroxetine (ROR 5.54; 95 % CI 3.92-7.83), venlafaxine (ROR 3.50; 95 % CI 1.93-6.36), fluoxetine (ROR 3.46; 95 % CI 2.26-5.29), citalopram (ROR 2.69; 95 % CI 1.28-5.67) and sertraline (ROR 2.49; 95 % CI 1.03-6.01). CONCLUSION: It is likely that there are instances of underreporting, particularly for ADRs that are embarrassing to talk about spontaneously. Despite the likely underreporting of this well-described adverse effect, this case/non-case study performed in a large national pharmacovigilance database confirms the existence of the risk of sexual disorders associated with SRIs, and is an example of the lack of sensitivity of spontaneous notification to measure ADRs. Minimization of antidepressant-induced sexual dysfunction could be an important factor to avoid unsuccessful treatment. Physicians should advise their patients on the possible sexual adverse effects.