Clinical study of OKY-046, a thromboxane synthetase inhibitor, in prevention of cerebral vasospasms and delayed cerebral ischaemic symptoms after subarachnoid haemorrhage due to aneurysmal rupture: a randomized double-blind study.

A double-blind study was conducted at 48 neurosurgical services in Japan to investigate the usefulness of OKY-046, an imidazole derivative and a thromboxane synthetase inhibitor, on cerebral vasospasm and cerebral ischaemic symptoms in patients with ruptured cerebral aneurysms. OKY-046 was administered in two daily doses of 80 mg (L group) and 400 mg (H group), and compared with a group given a placebo (P group). The following results were obtained: the occurrence of cerebral vasospasm was significantly lower in the L group than in the P group; the development of low density area (LD) in CTs was significantly lower in both the L and H groups than in the P group; motor paralysis in the L group improved significantly sooner, and that in the H group tended to improve sooner than that in the P group; in subjects with severe vasospasm, the incidence of LD was significantly lower, with better functional prognosis, in the L group than in the P group; in subjects with severe grades on the Glasgow Coma Scale (GCS), Japan Coma Scale (JCS) or High Density (HD) Score the functional prognosis at 1 month after the aneurysmal rupture was significantly better in the L group than in the P group, though no significant differences were seen in the overall investigation; there were no significant differences among the three groups in the development of either laboratory-determined abnormality or of adverse reactions. It is thus concluded that OKY-046 is clinically useful at a dose of 80 mg/d for cerebral vasospasm and cerebral ischaemic symptoms after subarachnoid haemorrhage (SAH) caused by aneurysmal rupture.