1. There is no other drug, save nicotine, that is routinely delivered via smoke inhalation. Useful drugs are delivered by drops, orally, IV, IM, and topically. Yes, we have nebulizers/inhalers to treat respiratory disease, but inhalation is not the way to treat systemic disease. That’s because the risks include lung cancer, emphysema, and bronchiolitis. Life-threatening lung damage is not a good trade-off for treating glaucoma.
2. The duration of action of marijuana is at best about 2 hours. That is not practical for glaucoma treatment. Most patients cannot adhere to 4x daily pilocarpine, so it’s usage has nearly disappeared. The cutting edge of drug research is now in extended release formulations (subconj, intracameral) that work for months per dose. Knowing that nonadherence is rampant, why would I choose a drug needing 12x daily dosing? It’s too short-acting to be useful. Until someone comes out with a THC ocular implant, I won’t be recommending it.
This outline was created by Dr. Jeff Kalenac and this information is endorsed by the Gulf Coast Glaucoma Clinic.