Intracranial Administration of Nicardipine After Aneurysmal Subarachnoid Hemorrhage: A Review of the Literature

Background: Intrathecal (IT), intraventricular (IVt), and intracisternal administration of nicardipine deliver treatment directly into the central nervous system. This route of drug delivery is being investigated as a potential treatment of vasospasm following aneurysmal subarachnoid hemorrhage (aSAH). Objective: The authors reviewed the existing literature regarding the direct administration of nicardipine into the intracranial space for the treatment of vasospasm following aSAH. Methods: An electronic search of literature published between 1994 and 2018 was performed using PubMed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. A variety of combinations of the search terms “intrathecal nicardipine,” “intraventricular nicardipine,” and “nicardipine prolonged-release” were used. Results: A total of 17 studies were included in this systematic review, 3 of which were studies in animals. The studies consistently demonstrated that IT nicardipine successfully reverses vasospasm, but the effect, as shown in some studies, was limited to the immediate vicinity of drug release. The data regarding long-term clinical outcomes are variable, with some studies demonstrating marked improvement whereas others fail to demonstrate improved outcomes when compared with patients who receive standard of care. Although adverse sequalae were uncommon, IT and IVt administration and therapy were associated with adverse effects including headache, meningitis, and hydrocephalus. Conclusions: Given the findings presented in these studies, IT, IVt, and intracisternal (pellet) nicardipine administration can be useful treatment adjuncts for vasospasm following aSAH, especially in cases refractory to conventional forms of treatment. However, larger, controlled clinical trials are warranted.