The Role of Parenteral Dantrolene in the Contemporary Management of Cerebral Vasospasm in Aneurysmal Subarachnoid Hemorrhage: A Systematic Review

Objective Cerebral vasospasm remains a significant source of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage. Dantrolene has shown promise in several animal studies in the treatment of cerebral vasospasm. The present study seeks to critically review the evidence of its use in human subjects, aiming to 1) describe the forms and dosages used, 2) describe its safety profile, and 3) describe its effectiveness in treating cerebral vasospasm. Methods A systematic review of intra-arterial dantrolene use in cerebral vasospasm was performed. A total of 86 articles were identified across all databases, 6 of which were ultimately included in the present study. Primary outcomes included a description of the form and dosage of dantrolene prescribed, the incidence of adverse effects after dantrolene use, and its efficacy for the treatment of cerebral vasospasm. Results Study designs included 2 randomized controlled trials (33.3%), 2 case series (33.3%), and 2 case reports (33.3%). Both the intra-arterial and intravenous administration of dantrolene has been performed with varying dose regimens. Although there exists limited clinical information regarding side effects, a case of liver toxicity was reported. All existing studies reported benefit in vasospasm measured either by transcranial Doppler or digital subtraction angiography. The level of evidence was low, consisting largely of retrospective studies that had a high likelihood of bias. Conclusions Dantrolene is a promising new therapeutic agent in the treatment of cerebral vasospasm. Although existing reports of its use are encouraging, high-quality prospective randomized trials are necessary for recommendations pertaining to dose, route, indications, and efficacy.