Glaucoma Consult your pharmacist if you have glaucoma. Code G refers to ophthalmic decongestants and anticholinergics. Ophthalmic decongestants Naphazoline Oxymetazoline Phenylephrine Tetrahydrozoline Anticholinergics Atropine Dicyclomine Gylcopyrrolate Hyoscyamine Propantheline Scopalamine Antihistamines diphenhydramine, dimenhydrinate and doxylamine are coded G for their anticholinergic activity.
Pupillary dilation can precipitate an attack of narrow angle glaucoma in susceptible persons.
Undiagnosed or uncontrolled glaucoma patients may suffer damage to the optic nerve. Those with open angle glaucoma may also have a slight increase in intraocular pressure necessitating an adjustrnent in glaucoma therapy.