The first use of physostigmine in the treatment of atropine poisoning. A translation of Kleinwachter's paper entitled 'Observations on the effect of Calabar bean extract as an antidote to atropine poisoning'.

This paper describes a clinical experiment performed by Drs Kleinwächter and Niemetschek in Prague in 1864, which showed for the first time that oral Calabar bean extract (which contains physostigmine) reverses the toxic effects of atropine. Kleinwächter’s original paper is translated from the German. This paper relates the earliest known account of the use of physostigmine (as an extract of Calabar bean) in the treatment of systemic atropine poisoning, in Prague in 1864 [1]. It was a bold therapeutic step at the time, in view of the fact that the side effects of too large a dose were known to produce muscular weakness [2] and even paralysis and death [3]. It is significant that the two doctors involved (Dr Kleinwächter and Dr Niemetschek) were ophthalmologists [4], in view of various reports the previous year (1863) that the conjunctival application of an extract of Calabar bean counteracts the mydriatic action of atropine [3, 5–7].