Dopamine D(1) agonists can induce a full antiparkinsonian response but do not support previous hypotheses suggesting that D(1) agonists are more or less likely to produce dyskinesias than levodopa.

Studies in animal models show a selective D1 receptor agonist with full functional efficacy compared with dopamine to have antiparkinsonian efficacy of similar magnitude to levodopa, without the same propensity for inducing dyskinesia. To date, no such agent has been tested in humans. ABT‐431 is the prodrug of A‐86929, a full, selective D1 receptor agonist. Subjects (n = 14) with levodopa‐responsive Parkinson's disease received five doses of ABT‐431 (5, 10, 20, 30, and 40 mg) and one of placebo after a 12‐hour levodopa holiday. Response was assessed by using the Unified Parkinson's Disease Rating Scale motor subsection. Dyskinesia was separately graded. ABT‐431 showed efficacy significantly superior to placebo at doses of 10 mg and more, and of similar magnitude to that seen with levodopa. Dyskinesia was reduced in several patients after receiving ABT‐431. There were no serious adverse events, the most common minor events being nausea and emesis, dizziness, and hypotension. Assuming that ABT‐431 is not transformed in humans into an unknown active D2 metabolite, and remains selective for D1 receptors, it is the first dopamine D1 receptor agonist to demonstrate a full antiparkinsonian effect in patients with Parkinson's disease. These preliminary findings also suggest that it may exhibit a reduced tendency to provoke dyskinesia. The emergence of a well‐tolerated D1 agonist should allow for the development of a better understanding of the relation between motor efficacy and dyskinesia in Parkinson's disease. Ann Neurol 1999;45:736–741

This study provides further evidence for a mild defect in frontal cognitive processing in ALS patients that evolves only slowly, if at all, with time.

No abstract

This paper describes the psychomotor and mnesic effects of single oral doses of etifoxine (50 and 100 mg) and lorazepam (2 mg) in healthy subjects. Forty-eight healthy subjects were included in this randomized double blind, placebo controlled parallel group study [corrected]. The effects of drugs were assessed by using a battery of subjective and objective tests that explored mood and vigilance (Visual Analog Scale), attention (Barrage test), psychomotor performance (Choice Reaction Time) and memory (digit span, immediate and delayed free recall of a word list). Whereas vigilance, psychomotor performance and free recall were significantly impaired by lorazepam, neither dosage of etifoxine (50 and 100 mg) produced such effects. These results suggest that 50 and 100 mg single dose of etifoxine do not induce amnesia and sedation as compared to lorazepam.