The Risk of Venous Thromboembolism (VTE) in Men with Benign Prostatic Hyperplasia Treated with 5-Alpha Reductase Inhibitors (5ARIs).

BACKGROUND: Many men receive 5-alpha reductase inhibitors (5ARIs) for ongoing treatment of benign prostatic hyperplasia (BPH). The increased risk of cardiovascular complications with 5ARIs has been documented in BPH studies and the occurrence of cerebral venous thrombosis, presumably due to increased estrogen level following 5ARI use, was described in multiple case reports. The objective of this study was to determine if 5ARIs with or without alpha blockers (AB) were associated with an increased risk of venous thromboembolism (VTE) in males with BPH. METHODS: We conducted a nested case–control study among a population of men ages 40–79 who received at least one 5ARI or AB prescription for treatment of BPH between 1995 and 2015 in the UK-based Clinical Practice Research Datalink GOLD. Cases of incident VTE (pulmonary embolism [PE] or deep venous thrombosis [DVT]) and matched controls were identified from this population. We used descriptive analyses and conditional logistic regression to evaluate the risk of VTE in users of 5ARIs compared to users of ABs. RESULTS: For 5ARI only users, the adjusted odds ratios (aORs), (95% CI) for VTE were 1.51 (0.98–2.32) in current 5ARI users and 1.23 (0.70–2.17) in recent/distant past, compared to AB only users. However, the aOR (95% CI) in men who had 50 or more current 5ARI prescriptions compared to users of ABs only was higher: 2.29 (1.14–4.63). For 5ARI with AB use, the aORs, (95% CI) for VTE were 1.16 (0.64–2.10) in current 5ARI+AB users and 1.93 (0.71–5.25) in recent/distant past, compared to AB only users. The aOR (95% CI) in men who had 50 or more current 5ARI+AB prescriptions compared to users of ABs only was 1.65 (0.64–4.26). CONCLUSION: Current use of 5ARI, particularly long-term use, is associated with an increased risk of incident idiopathic VTE compared to patients treated with AB use only.