Because of their pharmacological properties, antimuscarinic drugs expose patients to reductions in saliva production, in bronchial and mucus secretions, and in perspiration. These drugs also reduce tear production and can therefore cause ocular dryness, which is often reversible when the medication is discontinued. The symptoms of dry eye disease range from discomfort to pain all the way to corneal lesions that can cause scars and impaired vision. According to a report by the French Ophthalmological Society, dry eye accounts for some 25% of consultations with ophthalmologists.

Medications with antimuscarinic effects are commonly used in many different situations. With most antimuscarinics used in urinary incontinence, dry eye is mentioned as a frequent adverse reaction; often dose-dependent, its frequency is highly variable and difficult to assess.

Some antidepressants (imipramine and related drugs) have antimuscarinic effects and are implicated in dry eye disease.

Many other drugs have antimuscarinic effects including some neuroleptics, H1 antihistamines, antiparkinsonian drugs and bronchodilators.

The addition of several antimuscarinic drugs increases the frequency and intensity of dry eye symptoms. Dry eye is the most important cause of dissatisfaction and discontinuation of contact-lens use.

©Prescrire 1 May 2020

"Antimuscarinic drugs: dry eyes" Prescrire Int 2020; 29 (215): 132. (Pdf, subscribers only).

Share