Abstract P453: Histamine 2 Blockers and Nimodipine in Aneurysmal Subarachnoid Hemorrhage Patients

Background: Histamine (H) 2 blockers led to a significant increase of the relative bioavailability of nimodipine and therefore may change tolerability of nimodipine in patients with aneurysmal subarachnoid hemorrhage (SAH). Objective: To determine the effect of H2 blockers on outcome of SAH patients being treated with nimodipine on outcomes. Methods: We analyzed data from Cerner Health Facts® which collected data from participating facilities from January 1st, 2000 to July 1st, 2018. We identified SAH patients who underwent endovascular or surgical treatment for intracranial aneurysm and received nimodipine with or without H2 blockers. Outcome was defined by discharge destination and classified into none to minimal disability, moderate to severe disability, or death. Results: A total of 815 (54.8%) of 1488 SAH patients received H2 blockers in addition to nimodipine. There were no differences in rates of cerebral ischemia (8.8% versus 9.8%) or performance of angioplasty (3.8% versus 3.7%) between patients who did or did not receive H2 blockers. There were no differences in rates of intubation/mechanical ventilation (26.0% versus 29.3%) or intra-procedural cerebral infarction (3.4% versus 2.8%) between the two groups. There was no difference in in hospital mortality rates (10.9% versus 10.2%) or none to minimal disability (41.8% versus 38.2%) between patients who did or did not receive H2 blockers. Conclusions: H2 blockers are frequently used with nimodipine in SAH patients and did not appear to adversely affect rates of death or disability. The finding does not support any clinically significant interaction between H2 blockers and nimodipine in SAH patients.