Anterograde and Retrograde Amnesia after Lormetazepam and Flunitrazepam

In a pharmacopsychological study, memory impairments after single oral doses of benzodiazepines or placebo were investigated in 40 healthy men aged 20–40 years. The study was designed as a double-blind and placebo-controlled trial. Four independent groups of 10 subjects randomly received either 1 mg lormetazepam, 2 mg lormetazepam, 2 mg flunitrazepam, or placebo. The tests consisted of word lists, picture tests, and syllable pairs (consonant-vowel-consonant tri-grams). Tests were performed before drug ingestion, and 1, 2, 3, and 5 h after application. Different test versions were used on each occasion. The target variables were immediate recall (after presentation and a 10-s distraction task) and delayed recall and recognition (after 30 min). Recognition was also tested after 24 h for all five versions.