Richard Peatfield, MD FRCP
Princess Margaret Migraine Clinic, Charing Cross Hospital, London W6 8RF, U.K.
Prof. Dr. Carlos M. Villalón PhD
Departamento de Farmacobiología, Cinvestav-‐Coapa, Deleg. Tlalpan, 14330 México D.F., MEXICO
Many hypnotic and tranquillising drugs can also induce amnesia, an effect exploited by anaesthetists when performing potentially distressing medical procedures such as endoscopies in anxious patients. Unfortunately, many of the drugs have also found a place in criminal youth culture, enabling the unscrupulous to render victims powerless to resist sexual assault or even theft. As a result some of these agents, including flunitrazepam (Rohypnol) have been withdrawn from sale. Many are benzodiazepines, and are sedative, which is often useful in legitimate clinical practice, but (it may be assumed) less so when such drugs are used for criminal purposes. The muscarinic receptor antagonist scopolamine (l-‐hyoscine), derived from Henbane in Europe, has been used as an anaesthetic premedication for many years, as it simultaneously inhibits vagal reflexes, dries oral secretions and impairs memory, without suppressing respiration.