SAN DIEGO — Marijuana is not recommended for glaucoma treatment, but with its increasing acceptance, clinicians need to be ready for patients to ask about it, Anurag Shrivastava, MD, said at Glaucoma Subspecialty Day at the American Society of Cataract and Refractive Surgery annual meeting.
Neither the American Academy of Ophthalmology nor the American Glaucoma Society recommend the drug for glaucoma treatment.
The drug does have an IOP lowering effect that is unrelated to its hypotensive effect, Shrivastava said. The mechanism of action is thought to be due to decreased aqueous secretion and enhanced uveoscleral outflow.
“The duration of action is one of the most spoken about reasons why this is not the right therapy for our patients,” he said.
Using an inhaled route of administration, the effects would last 3 to 4 hours, necessitating every 3-hour dosing around the clock. Apart from an unsustainable dosing regimen, other considerations include side effects of lung cancer with prolonged use, somnolence, euphoria, tachycardia and central nervous system effects, including memory loss, mood alteration and difficulty concentrating.
Another consideration is the increased potency of the drug since the 1970s. The concentration of THC (tetrahydrocannabinol), the main psychoactive component in marijuana, is 10-fold greater now than it was then, he said.
“This has actually led the American Psychiatric Association to come up with the diagnosis of CUD, which is cannabis use disorder, which is probably going to become more diagnosed in coming years as utilization continues,” he said. “There’s also an effect on blood pressure and decreased perfusion [of the optic nerve], so these are all things we have to think about in our talks with patients.” – by Patricia Nale, ELS
Reference: Shrivastava A. Weeding out glaucoma therapies. Presented at: American Society of Cataract and Refractive Surgery annual meeting; May 3-7, 2019; San Diego.
Disclosure: Shrivastava reports no relevant financial disclosures.