The clinical efficacy of a single afternoon dose of levodopa methyl ester: a double-blind cross-over study versus placebo.

Levodopa methyl ester (LDME) is a highly water soluble derivative produced by esterification of the carboxilic acid moiety of the L-Dopa molecule that is rapidly hydrolyzed to L-Dopa and can be administered orally in an easily dosable liquid form. In this study the relative efficacy and tolerability of a single dose of an oral solution of 250 mg of LDME was compared to that of placebo in reversing afternoon off period. A controlled double-blind cross-over study versus placebo had previously been carried out in 25 idiopathic parkinsonian patients with predictable fluctuations in motor performances. The study design stipulated the sequential administration of LDME and placebo in group A and placebo and LDME in group B on two consecutive days. All patients turned "on" with LDME and none with placebo solution. The mean latency to "on" was 25.3 +/- 13.5 min for the A group and 27.6 +/- 3.9 min for group B (Fig. 2) and the "on" duration was 147.7 +/- 50.3 min and 163.3 +/- 39.3 min for the A and B groups respectively. Five patients suffering from drug resistant "off" phenomena turned "on" with LDME solution showing a mean latency to "on" of 31.4 +/- 6.2 min.