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.