Speaker: Education key in treating glaucoma patients on multiple medications

ATLANTA – It is essential that optometrists educate themselves, doctors of other disciplines and patients about conflicting drugs when treating glaucoma, according to a speaker here at SECO.

Tammy Than, MS, OD, FAAO, discussed on Saturday the dangers of different types of medication that could cause drug-induced glaucoma or exacerbate existing glaucoma.

Glaucoma patients tend to be older, Than explained.

Tammy Than

“They are on multiple medications systemically, so you kind of have a perfect storm,” she said. “You've got older patients, patients with thicker lenses who are predisposed to angle closure and they also have impaired metabolism, so their medications are staying longer."

Cholinergic agonists, cholinergic antagonists such as antihistamines, antidepressants, chronic occlusive pulmonary disease and emphysema medications, overactive bladder medications and sympathomimetics can cause or worsen open-angle glaucoma, according to Than's presentation.

She also warned that not all drugs with potential conflicts come from another doctor. Many are sold over-the-counter, and patients are not educated on how they could be affected.

Optometrists should be concerned about antihistamines that are strongly sedating, Than said.

“Those are the ones that have the greatest level of anticholinergic properties and, therefore, the most likely to cause pupillary dilation and angle closure," she said.

Benadryl (diphenhydramine, McNeill Consumer) is commonly used, “so that would be the one to mostly be concerned about,” Than said.

She also cautioned against nutritional supplements including jimson weed and valerian root, which can also poorly affect glaucoma patients.

Than reviewed drugs that can contribute to idiosyncratic angle closure, such as Topamax (topiramate, RW Johnson) and Qsymia (phentermine and topiramate, Vivus), as well as oral steroids, cancer medications and caffeine, which can further open the angle.

Than stressed the importance of closely monitoring patients taking agents that may cause adverse ocular effects.

Drug history is important, as is communicating with the prescriber, she said.

“Lastly, if you see something that has not been previously reported, report it to MedWatch,” she concluded. “That's really important." – by Chelsea Frajerman

Disclosure: Than has no relevant financial interests.