Doxepin Use in Open-Angle Glaucoma
Yes, a patient with open-angle glaucoma can safely take doxepin, as tricyclic antidepressants pose minimal risk in open-angle glaucoma—the primary concern with anticholinergic medications is angle-closure glaucoma, not open-angle glaucoma.
Key Distinction: Open-Angle vs. Angle-Closure Glaucoma
The critical factor here is understanding which type of glaucoma poses risk with anticholinergic medications:
- Anticholinergics (including tricyclic antidepressants like doxepin) should be used with caution in narrow-angle glaucoma, but are less problematic in open-angle glaucoma 1
- The package insert warnings about "glaucoma" on medications that may dilate the pupil can essentially be ignored for patients with any type of glaucoma in practical clinical use 2
- The real danger in open-angle glaucoma comes from chronic corticosteroid use (especially eye drops), not from anticholinergic medications 2
Understanding the Mechanism
The concern with anticholinergic medications relates to pupillary dilation and angle closure:
- Tricyclic antidepressants, certain SSRIs, and other antidepressants have been reported to precipitate acute angle-closure glaucoma in predisposed individuals with narrow anterior chamber angles 3, 4
- Open-angle glaucoma, by definition, has an open anterior chamber angle on gonioscopy and is not susceptible to this mechanism of acute pressure elevation 5
- The mydriasis (pupil dilation) caused by anticholinergic effects is only problematic when the anatomical angle is already narrow 3
Clinical Recommendations
For your patient with open-angle glaucoma considering doxepin:
- Proceed with doxepin without significant concern for worsening glaucoma 1, 2
- Ensure the patient continues their regular glaucoma medications (typically prostaglandin analogs as first-line therapy) 6, 7
- Maintain regular ophthalmologic follow-up to monitor intraocular pressure and optic nerve status, as recommended for all open-angle glaucoma patients 1
- Counsel the patient on medication adherence, as nearly 45% of glaucoma patients take fewer than 75% of prescribed doses 6, 7
Important Caveat
Verify that the patient truly has open-angle glaucoma and not narrow-angle or angle-closure glaucoma, as this distinction is critical for medication safety 3, 4. If there is any uncertainty about the glaucoma type, consultation with the patient's ophthalmologist is warranted before initiating doxepin 3.