Angiotensin-converting enzyme inhibitors do not impair the safety of Hymenoptera venom immunotherapy build-up phase.

BACKGROUND: There is an ongoing debate on whether angiotensin-converting enzyme inhibitors (ACEI) should be substituted prior to initiation of venom immunotherapy (VIT) for safety reasons. OBJECTIVE: We aimed to assess the influence of ACEI medication on the incidence of systemic reactions (SR) during the build-up phase of VIT in a large and homogeneous cohort of patients. METHODS: The frequency of SR during 775 consecutive cycles of VIT initiation was analyzed in relation to cardiovascular medication, age, sex, venom, reactivity in diagnostic tests, severity of preceding sting-induced anaphylaxis, comorbidities, latency before the initiation of VIT, and treatment protocols. ACEI were routinely maintained throughout VIT, beta-blockers replaced if appropriate. RESULTS: During VIT-initiation, 190 (24.5%) patients were on some kind of cardiovascular treatment, 90 (11.6%) on ACEI, 23 (3.0%) on beta-blockers. VIT-related SR rates were 11.7% (any documented reactions including subjective symptoms) and 3.0% (reactions fulfilling objective diagnostic criteria of anaphylaxis). Medication with ACEI (P = 0.097) or beta-blockers (P = 1.0) was not significantly related to the incidence of SR. A reduced rate of SR in patients taking cardiovascular drugs was not statistically significant in the final multivariate regression model. A prolonged latency before the initiation of VIT (P = 0.018, odds ratio = 1.010), and use of 5-day compared to 3-day rush protocols (P = 0.008, odds ratio = 3.522) increased the frequency of SR. CONCLUSIONS AND CLINICAL RELEVANCE: Study data do not provide evidence of an ACEI-mediated increase of VIT-related SR, supporting the continued use of these valuable and hard-to-replace substances throughout VIT.