Antimuscarinics

Atropine sulfate is now rarely used for premedication but still has an emergency role in the treatment of vagotonic side effects and is also used to treat acute arrhythmias after myocardial infarction.

Hyoscine hydrobromide reduces secretions and also provides a degree of amnesia, sedation and anti-emesis. Unlike atropine it may produce bradycardia rather than tachycardia. In some patients, especially the elderly, hyoscine may cause the central anticholinergic syndrome.

Glycopyrronium bromide reduces salivary secretions. When given intravenously it produces less tachycardia than atropine. It is widely used with neostigmine for reversal of non-depolarising neuromuscular blocking drugs.