Introduction

Anticholinergic alkaloid agents, such as atropine and scopolamine, exist in the roots, seeds and leaves of a variety of plants. Atropa belladonna (deadly nightshade) and Datura stromonium (jimsonweed, stinkweed, devil's apple or thorn apple) contain atropine, whereas the alkaloid scopolamine (hyoscine) is found in the shrub Hyoscyamus niger and Scopolia carnolica. These plants have been used in herbal remedies for many centuries. The earliest written record of their medical use is from seventeenth-century Aryuvedic literature discussing the use of Datura specifically for asthma. They were introduced into Europe in 1802 by General Gent who, while stationed in Madras, had found that smoking stramonium alleviated his asthma as well as in others. In 1859, it was reported that a severe asthma attack was successfully treated by injection of atropine into the vagus nerve. By the end of the nineteenth century, anticholinergic alkaloids enjoyed enormous use as bronchodilators. Their use declined after the discovery of adrenaline in the 1920s, followed soon by ephedrines, other adrenegic agents and then methylxanthines. Natural anticholinergic agents such as atropine produced many side effects that resulted in poor acceptability by patients. More recently, advances in the understanding of the role of the parasympathetic system in controlling airway tone, and the improved side effect profile of synthetic topically active derivatives of atropine have renewed interest in anticholinergic agents, particularly in the therapy of COPD.