NICE summary of review conclusions Limited evidence suggests that oral nimodipine demonstrates increased benefits by reducing the risks of poor outcome and secondary ischaemia, with only modest risks. Evidence shows that the harms of intravenous calcium antagonists for aneurysmal subarachnoid haemorrhage may outweigh the benefits. The intravenous administration of calcium antagonists should not be offered for routine use, given the limited evidence to support its use, higher costs and potentially higher risk of hypotensive effects. Consider replacing intravenous calcium antagonists with oral nimodipine for routine use in the management of aneurysmal subarachnoid haemorrhages, which may lead to improved patient outcomes and patient safety through reduced adverse events. The 'Implications for practice' section of the Cochrane review stated: 'Based on our conclusions, we recommend oral nimodipine (60 mg every 4 hours, to be continued for 3 weeks) as standard treatment in patients with aneurysmal subarachnoid haemorrhage. Although the evidence about the beneficial effect of nimodipine is not beyond all doubt, and is mainly based on one large study where aneurysms were treated with surgical clipping, we recommend oral nimodipine given the potential benefits and modest risks associated with it. Intravenous administration of calcium antagonists is more expensive and potentially hazardous in view of hypotensive effects, and is therefore not recommended.'