RT Journal Article SR Electronic T1 Effect of indomethacin on cerebral blood flow, carbon dioxide reactivity and the response to epoprostenol (prostacyclin) infusion in man. JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 51 OP 55 DO 10.1136/jnnp.47.1.51 VO 47 IS 1 A1 Pickles, H A1 Brown, M M A1 Thomas, M A1 Hewazy, A H A1 Redmond, S A1 Zilkha, E A1 Marshall, J YR 1984 UL http://jnnp.bmj.com/content/47/1/51.abstract AB Cerebral blood flow (CBF) has been measured using a non-invasive Xenon133 clearance technique in six normal subjects after 2 days pretreatment with oral indomethacin at a dose of 100 mg/day. The results were compared with placebo given in a double blind balanced cross-over design. Indomethacin was found to result in a reduction in resting CBF of about 25% but the reactivity of the cerebrovascular circulation to carbon dioxide was preserved at normal levels. Infusions of epoprostenol (prostacyclin, PGI2) at a dose of 5 ng/kg/min resulted in a reduction of CBF of about 10% after placebo but no significant change in CBF after indomethacin. The results suggest that prostaglandins are involved in the maintenance of cerebrovascular tone but not in the mechanism of cerebral vasodilation accompanying hypercapnia. The combination of indomethacin and PGI2 has been proposed as a treatment of cerebral artery spasm and the findings suggest that the combination therapy would not be accompanied by undesirable intracerebral steal.