American Glaucoma Society Position Statement: Marijuana and the Treatment of Glaucoma

The federal government has given this woman, Elvy Musikka, medical marijuana to treat her glaucoma for decades now.

American Glaucoma Society Position Statement: Marijuana and the Treatment of Glaucoma

Henry Jampel, MD, MHS

One of the commonly discussed alternatives for the treatment of glaucoma by lowering IOP (inter-ocular pressure) is the smoking of marijuana. It has been definitively demonstrated, and widely appreciated, that smoking marijuana lowers IOP in both normal individuals and in those with glaucoma, and therefore might be a treatment for glaucoma. Less often appreciated is marijuana’s short duration of action (only 3 to 4 h), meaning that to lower the IOP around the clock it would have to be smoked every 3 hours.

You write that as if it were a bad thing.  How many prescriptions with much more deleterious side effects than cannabis do we regularly recommend to patients to take every three hours?

Furthermore, marijuana’s mood-altering effects would prevent the patient who is using it from driving, operating heavy machinery, and functioning at maximum mental capacity.

You know what else prevents people from driving and operating heavy machinery?  Blindness.

This illustrates the ignorance of the author in that he assumes that someone smoking cannabis every three hours would be so baked they would be incapable of basic functioning.  People who use cannabis consistently develop a tolerance to the psychoactive effects and are as capable as most people using other prescription medications.

The FDA-approved cannabinoid prescription, Marinol (100% potent THC), has the following warning: “Do not drive a car or operate machinery until you know how MARINOL Capsules affects you.” Which tells me that once you do know how Marinol effects you, go right ahead and drive.  So if that’s the warning for 100% pure THC, why again are we supposed to fear the 10%-20% THC cannabis user on the road?

The notion that regular cannabis use affects maximum mental capacity is also bunk.  Studies in 2002, 2006, and 2009 all show that regular cannabis use does not lead to cognitive decline.

Marijuana cigarettes also contain hundreds of compounds that damage the lungs, and the deleterious effect of chronic, frequent use of marijuana upon the brain is also well established.

Any smoke contains compounds that damage the lungs.  However, cannabis can be vaporized and studies have proven that to be a safe and effective delivery method.  Even for those that smoke rather than vaporize, we find that regular cannabis use does not lead to declines in pulmonary function or conditions like chronic obstructive pulmonary disease.

Although marijuana can lower the IOP, its side effects and short duration of action, coupled with a lack of evidence that its use alters the course of glaucoma, preclude recommending this drug in any form for the treatment of glaucoma at the present time.

So instead, your doctor can recommend to you a bunch of other drugs to be taken in eye-drop form (side-effects emphasis by me):

(Mayo Clinic)

• Beta blockers. These reduce the production of aqueous humor. Examples include levobunolol (Betagan), timolol (Betimol, Timoptic), betaxolol (Betoptic) and metipranolol (OptiPranolol). Possible side effects include difficulty breathing, slowed pulse, hair loss, lower blood pressure, impotence, fatigue, weakness, depression and memory loss. If you have asthma, bronchitis or emphysema, medications other than beta blockers may be recommended because beta blockers may worsen breathing problems. Your doctor also may recommend avoiding beta blockers if you’re taking insulin for diabetes.
• Alpha-agonists. These reduce the production of aqueous humor and increase drainage. Examples include apraclonidine (Iopidine) and brimonidine (Alphagan). Possible side effects include fatigue; dizziness; red, itchy or swollen eyes; dry mouth; and allergic reactions.
• Carbonic anhydrase inhibitors. These also reduce the production of aqueous humor. Examples include dorzolamide (Trusopt) and brinzolamide (Azopt). Frequent urination and a tingling sensation in the fingers and toes are possible side effects, occurring more often with oral carbonic anhydrase inhibitors than with anhydrase inhibitor eyedrops. If you have an allergy or sensitivity to sulfa drugs, don’t use these medications unless there’s no alternative.
• Prostaglandin-like compounds. These eyedrops increase the outflow of aqueous humor. Examples include latanoprost (Xalatan), bimatoprost (Lumigan) and travoprost (Travatan). Possible side effects include mild reddening and stinging of the eyes and darkening of the iris, changes in the pigment of the eyelid skin, and blurred vision from swelling of the retina.
• Miotic or cholinergic agents. These also increase the outflow of aqueous humor. Examples include pilocarpine (Isopto Carpine, Pilopine) and carbachol (Isopto Carbachol). Possible side effects are pain around or inside the eyes, brow ache, blurred or dim vision, nearsightedness, allergic reactions, a stuffy nose, sweating, increased salivation, and occasional digestive problems.
• Epinephrine compounds. These compounds, such as dipivefrin (Propine), also increase the outflow of aqueous humor. Possible side effects include red eyes, allergic reactions, palpitations, increased blood pressure, headache and anxiety.

Oral medications
If eyedrops alone don’t bring your eye pressure down to the desired level, your doctor may also prescribe an oral medication. Doctors commonly prescribe carbonic anhydrase inhibitors, such as acetazolamide (Diamox Sequels) and methazolamide (Neptazane), for glaucoma. Take these pills with meals to reduce side effects. Add bananas and apple juice to your diet to minimize the potassium loss caused by these medications.

Initially, carbonic anhydrase inhibitors may cause frequent urination and a tingling sensation in your fingers and toes. After several days, these symptoms usually disappear. Other possible side effects of carbonic anhydrase inhibitors include rashes, depression, fatigue, kidney stones, lethargy, stomach upset, a metallic taste in carbonated beverages, impotence and weight loss.

Gee, “marijuana’s mood-altering effects” don’t seem like that big a deal now, do they?