Hypotension and bradycardia possibly associated with intraocular injection of acetylcholine

Topically applied drugs are an important part of the pharmacologic management of cataract extraction and lens implant surgery. Acetylcholine facilitates this procedure via its miotic effect on the ciliary body of the eye. Systemic effects can occur with topically administered ophthalmic medications. Acetylcholine has been implicated in several cases of systemic cholinergic effects, such as hypotension, bradycardia, and bronchospasm, following intraocular administration. The patients we present experienced profound hypotension and bradycardia occurring up to 45 minutes after intraocular injection of acetylcholine. Both patients were over 90 years of age and had a history of first-degree atrioventricular block. As cataract surgery and lens implantation become more prevalent in the older ambulatory segment of the geriatric population, healthcare professionals should be aware that these patients may be more sensitive to the pharmacologic effects of medication used during surgery. Monitoring for adverse effects must be performed intraoperatively and several hours postoperatively. Additionally, patients with known conduction abnormalities prior to surgery should be monitored closely and proper emergency equipment and personnel should be available. Pharmacists who investigate adverse drug reactions should consider ophthalmic medications as potential causes for unexplained or suspected adverse drug reactions.