Safety of new oral anticoagulants

The efficacy and safety of edoxaban versus warfarin in preventing clinical events in atrial fibrillation: A systematic review and meta-analysis

Atrial fibrillation (AF) is the most common type of arrhythmia. Warfarin reduces the incidence and mortality of strokes in patients with AF. Edoxaban reduces the bleeding risk in patients with AF. This study evaluates the efficacy and safety of edoxaban versus warfarin in preventing clinical events in patients with AF through a meta-analysis of randomized controlled trials (RCTs). RCTs were retrieved from medical literature databases. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated to compare the primary and safety endpoints. In total, five articles (10 trial comparisons) containing 24,836 patients were retrieved. Of these patients, 16,268 (65.5%) received edoxaban and 8,568 (34.5%) received warfarin. Compared with warfarin, edoxaban significantly reduced the incidence of cardiovascular death (CVD), major bleeding, and non-major bleeding (RR: 0.86, 95% CI: 0.80-0.93, I2 : 0.0%; RR: 0.65, 95% CI: 0.59-0.71, I2 : 75.6%; and RR: 0.80, 95% CI: 0.77-0.84, I2 : 79.3%, respectively). Edoxaban did not increase the incidence of stroke, systemic embolic events, myocardial infarction, and adverse events compared with warfarin (RR: 1.00, 95% CI: 0.90-1.11, I2 : 42.8%; RR: 1.00, 95% CI: 0.67-1.49, I2 : 0.0%; RR: 1.08, 95% CI: 0.93-1.27, I2 : 0.0%; RR: 1.00, 95% CI: 0.91-1.10, I2: 46.4%, respectively). This meta-analysis indicated that compared with warfarin, edoxaban can significantly reduce the incidence of CVD and major and non-major bleeding. The anticoagulant effect and safety of edoxaban may be better than those of warfarin.

Safety profile of the direct oral anticoagulants: an analysis of the WHO database of adverse drug reactions

AIM

Direct oral anticoagulants (DOACs) have shown noninferiority to warfarin for stroke prevention in nonvalvular atrial fibrillation (AF) and a more promising safety profile. Unanswered safety aspects remain to be addressed and available evidence on the risk associated with these drugs are conflicting. In order to contribute to the debate on their safety profile, we conducted a comparative analysis of the reports of suspected adverse drug reactions (ADRs) associated with DOACs in VigiBase.

METHODS

Study based on reports of suspected ADRs held in VigiBase as at December 2014, in which a DOAC or warfarin were administered in patients with nonvalvular AF and listed as suspected/interacting drugs. Medical Dictionary for Regulatory Activities was used to classify ADRs. Reporting odds ratio (ROR) with 95% confidence interval were calculated. Results with P ≤ 0.05 were statistically significant.

RESULTS

We retrieved 32 972 reports. We identified 204 ADRs with a ROR >1 (P ≤ 0.05) and we focused on 105 reactions. Positive ROR emerged for DOACs and gastrointestinal haemorrhage compared with warfarin [(1.6 (1.47-1.75)], but no disproportionality with cerebral haemorrhage was found [0.31 (0.28-0.34)]. We identified other potential signals that have not been associated with DOACs previously.

CONCLUSIONS

As well as premarketing authorization clinical trial studies, we found a reduced risk of intracranial haemorrhage, but an increased risk of gastrointestinal haemorrhage in patients treated with DOACs compared to warfarin. We provide new data and we highlight several differences between the three novel oral anticoagulants, in the rate and type of ADRs occurred.