Limaprost.

Limaprost, an alprostadil (prostaglandin E1) analogue, is a vasodilator that increases blood flow and inhibits platelet aggregation. The efficacy of oral limaprost was evaluated in adult Japanese patients in three randomised, double-blind, 6-week trials. One study included patients with thromboangiitis obliterans and two trials included patients with lumbar spinal canal stenosis. Limaprost was generally well tolerated and serious adverse events were uncommon. THROMBOANGIITIS OBLITERANS: In a randomised, double-blind trial in Japanese patients primarily with thromboangiitis obliterans (n=136), there was no significant difference between patients receiving limaprost 30 microg/day and those receiving oral ticlopidine 500 microg/day in the improvement of ischaemic symptoms. LUMBAR SPINAL CANAL STENOSIS: Limaprost 15 microg/day was superior to limaprost 3 microg/day for overall drug usefulness and overall improvement from baseline to study end in a phase III trial in 146 patients with lumbar spinal canal stenosis. Assessment of overall improvement considered various objective symptoms (e.g. muscle strength, walking ability) and subjective symptoms (e.g. pain or numbness in extremities), while overall usefulness also considered safety issues. The efficacy of limaprost 15 microg/day was not significantly different from that of 30 microg/day, but tended to be better than that of 6 microg/day in a phase II trial in patients with lumbar spinal canal stenosis and normal straight leg raise test results. The optimal dosage of limaprost for this indication was therefore deemed to be 15 microg/day.