RT Book, Section A1 Butterworth IV, John F. A1 Mackey, David C. A1 Wasnick, John D. SR Print(0) ID 1161426954 T1 Anticholinergic Drugs T2 Morgan & Mikhail's Clinical Anesthesiology, 6e YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9781259834424 LK accessanesthesiology.mhmedical.com/content.aspx?aid=1161426954 RD 2024/04/25 AB KEY CONCEPTS The ester linkage is essential for effective binding of the anticholinergics to the acetylcholine receptors. This competitively blocks binding by acetylcholine and prevents receptor activation. The cellular effects of acetylcholine, which are mediated through second messengers, are inhibited. Anticholinergics relax the bronchial smooth musculature, which reduces airway resistance and increases anatomic dead space. Atropine has particularly potent effects on the heart and bronchial smooth muscle and is the most efficacious anticholinergic for treating bradyarrhythmias. Ipratropium solution (0.5 mg in 2.5 mL) seems to be particularly effective in the treatment of acute chronic obstructive pulmonary disease when combined with a β-agonist drug (eg, albuterol). Scopolamine is a more potent antisialagogue than atropine and causes greater central nervous system effects. Because of its quaternary structure, glycopyrrolate cannot cross the blood–brain barrier and is almost devoid of central nervous system and ophthalmic activity.