Benadryl and Glaucoma

Various drugs have the prospective to elevate eye pressure and increase the risk of developing glaucoma. This post explores the classes of medications that may impact the open-angle and angle-closure types of glaucoma.

Benadryl (diphenhydramine) is an antihistamine that reduces the impacts of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.

Benadryl is used to treat sneezing, runny nose, watery eyes, hives, skin rash, itching, and other cold or allergy symptoms.

Benadryl is likewise used to treat movement sickness, to induce sleep, and to treat certain symptoms of Parkinson’s disease.

benadryl and glaucoma
Benadryl when you have glaucoma

Most medications that might negatively impact glaucoma, or increase the opportunity of establishing glaucoma, have the prospective to narrow the drain angle of your eye, called the trabecular meshwork. This would prevent eye fluid from exiting appropriately resulting in high eye pressure. The “angle” that is being described is the angle in between the iris, which makes up the colored part of your eye, and the cornea, which is the clear window front part of your eye.

Therefore, if you have a recognized history of narrow angles or the condition known as angle-closure glaucoma, you need to absolutely call your ophthalmologist prior to using any medication that has a glaucoma warning.

The list below elements increase risk for developing medication-induced angle closure:

  • advanced age
  • female gender
  • hyperopia (farsightedness).
  • Asian ethnic background.
  • favorable family history of angle-closure glaucoma.
  • understood preexisting narrow angles.

How does Benadryl affect to people with glaucoma? As an anti-allergy over-the-counter drugs which contain diphenhydramine put patients with narrow angles and angle-closure glaucoma at risk.

So if you have open-angle glaucoma, the risk of side effects from Benadryl is nearly absolutely no.

Reyus Mammadli (Eyexan Team Leader)/ author of the article

My name is Reyus Mammadli. I’m the author and editor of this health blog, active since 2008. With a background in medical and biotechnical devices, I focus on making health and self-care topics—especially in ophthalmology—clear and accessible.

Although I’m not a licensed physician, I’ve spent over 15 years working with medical literature and guidelines, with particular attention to trusted ophthalmic sources such as the American Academy of Ophthalmology, National Eye Institute, and PubMed. I also follow the latest updates in diagnostics and treatment technologies.

My aim is to help readers better understand eye diseases, tests, and treatment options—so they can feel more confident when consulting a doctor.

Note: This blog does not provide medical diagnoses or treatments. It offers clear, reliable health information to support informed conversations with healthcare professionals.