Definition of physostigmine in English:



mass nounChemistry
  • A compound which is the active ingredient of the Calabar bean and is used medicinally in eye drops on account of its anticholinesterase activity.

    A tricyclic alkaloid; chemical formula: C₁₅H₂₁N₃O₂

    • ‘Some authorities have recommended against the use of physostigmine because of its frequent association with increased bronchial secretions and its rare association with asystole.’
    • ‘But since physostigmine could be isolated only from the Calabar bean, the drug was not readily available.’
    • ‘Julian was interested in medicinal plants, particularly the Calabar bean whose active principle, physostigmine, was first isolated by the German chemists Jobst and Hesse in 1864.’
    • ‘Compared with placebo, an infusion of physostigmine produced a 21% decrease in apnea-hypopnea index and a 23% increase in the minimum level of oxygen saturation.’
    • ‘The symptoms of anticholinergic overdose may be treated with physostigmine in a dosage of 1 to 2 mg given intramuscularly or intravenously at 20-minute intervals.’


Mid 19th century: from the modern Latin genus name Physostigma (to which the Calabar bean belongs) + -ine.