BACKGROUND: Secondary ischaemia is a frequent cause of poor outcome in patients 
with subarachnoid haemorrhage (SAH). Its pathogenesis has been incompletely 
elucidated, but vasospasm probably is a contributing factor. Experimental 
studies have suggested that calcium antagonists can prevent or reverse vasospasm 
and have neuroprotective properties.
OBJECTIVES: To determine whether calcium antagonists improve outcome in patients 
with aneurysmal SAH.
SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register (last 
searched April 2006), MEDLINE (1966 to March 2006) and EMBASE (1980 to March 
2006). We handsearched two Russian journals (1990 to 2003), and contacted 
trialists and pharmaceutical companies in 1995 and 1996.
SELECTION CRITERIA: Randomised controlled trials comparing calcium antagonists 
with control, or a second calcium antagonist (magnesium sulphate) versus control 
in addition to another calcium antagonist (nimodipine) in both the intervention 
and control groups.
DATA COLLECTION AND ANALYSIS: Two review authors independently extracted the 
data and assessed trial quality. Trialists were contacted to obtain missing 
information.
MAIN RESULTS: Sixteen trials, involving 3361 patients, were included in the 
review; three of the studies were of magnesium sulphate in addition to 
nimodipine. Overall, calcium antagonists reduced the risk of poor outcome: the 
relative risk (RR) was 0.81 (95% confidence interval (CI) 0.72 to 0.92); the 
corresponding number of patients needed to treat was 19 (95% CI 1 to 51). For 
oral nimodipine alone the RR was 0.67 (95% CI 0.55 to 0.81), for other calcium 
antagonists or intravenous administration of nimodipine the results were not 
statistically significant. Calcium antagonists reduced the occurrence of 
secondary ischaemia and showed a favourable trend for case fatality. For 
magnesium in addition to standard treatment with nimodipine, the RR was 0.75 
(95% CI 0.57 to 1.00) for a poor outcome and 0.66 (95% CI 0.45 to 0.96) for 
clinical signs of secondary ischaemia.
AUTHORS' CONCLUSIONS: Calcium antagonists reduce the risk of poor outcome and 
secondary ischaemia after aneurysmal SAH. The results for 'poor outcome' depend 
largely on a single large trial of oral nimodipine; the evidence for other 
calcium antagonists is inconclusive. The evidence for nimodipine is not beyond 
all doubt, but given the potential benefits and modest risks of this treatment, 
oral nimodipine is currently indicated in patients with aneurysmal SAH. 
Intravenous administration of calcium antagonists cannot be recommended for 
routine practice on the basis of the present evidence. Magnesium sulphate is a 
promising agent but more evidence is needed before definite conclusions can be 
drawn.