Beta Blockers – Glaucoma Medication | Driving with Dr. David Richardson– Series 5 Ep 01
Hello, I’m Dr. David Richardson. I’m a cataract and glaucoma surgeon in Southern California. On my morning commutes, I like to discuss those topics that there’s generally not enough time to discuss in the exam room.
Today, I’d like to talk about a class of glaucoma medications, the beta blocker class.
So let’s go now!
The beta blocker class of medications has been around in medicine for over 50 years. Primarily, this class of medications is used as a pill form to treat things, such as high blood pressure and fast heart rate. So it lowers heart rate. It lowers blood pressure. And as it turns out, it also lowers intraocular pressure or iop. Now the first set of topical beta blockers eye drops used to control glaucoma were not very successful because they were toxic to the corneal surface but, timolol was developed and this turned out to be both effective and well tolerated indeed. Timolol is still the most commonly prescribed beta blocker and one of the most commonly prescribed eye drops as treatment for glaucoma. Now if you are going to be prescribed timolol, it will come in a bottle form in general, unless you get the preservative-free version called Ocudose. The bottles generally have a yellow cap for the one-half percent or a light blue cap for the quarter percent. Timol itself works to reduce the amount of fluid, produced in the eye, so it works on the ciliary body where fluid is produced and it primarily works during the day at night when we’re sleeping. We do not produce much aqueous fluid and so there’s not a whole lot of benefit to using timol at night. With that in mind, we have to consider how it’s dosed traditionally. Timol was dosed twice daily and in many of the formulations that are what are called fixed combinations, so timol plus another class of medication, these have to be taken twice a day because the other class doesn’t work well, unless it’s taken at least twice a day. Those classes are the carbonic anhydrase inhibitors as well as the alpha agonist and, so, the two fixed combination agents are cosopt which is timol plus a carbonic anhydrase inhibitor. And I’ll speak about that class in another video as well as combigan which is timol plus brimonidine which is in the alpha agonist class. And again I’ll speak about that in another video.
So, in any case traditionally, timolol has been prescribed twice daily but, as I just said, timolol doesn’t work all that well at night. Worse the bitter blockers can actually have a negative impact on the profusion of the optic nerve, so the ability of the blood supply to get to the optic nerve especially in people who are called dippers where their systemic blood pressure drops by a certain percentage or more at night. So I’ve actually gotten away from prescribing timolol or any of the beta blocker classes in the evening for those who are on a fixed combination agent where they really do need to use it twice a day. I recommend the first dose in the morning and the second dose in the early afternoon, generally no later than 4 pm because I do not want there to be any adverse impact on the systemic blood pressure. Now how well does timolol work? Timolol during the day works really well. In fact, it is the most effective medical treatment for elevated intraocular pressure with one exception. And that exception is the prostaglandin analog class which again, as discussed in another video, at night not so much as I just mentioned. How about side effects, side effects for the topical beta blockers? Local side effects include some redness, maybe some blurriness which is usually transient, so it’s usually just temporary. And then the other thing is systemic side effects. And this is really the weakness of the beta blocker class. So the beta blockers as an eye drop can have the same side effects that you see with the oral medication, so low heart rate, low blood pressure which we just talked about how that can be an issue at night. Those who have asthma, you can actually get exacerbation of your asthma because you do get some bronchoconstriction. This is also an issue for people who have chronic obstructive pulmonary disease or copd. And those with congestive heart failure should not take beta blockers without first consulting their cardiologist. There are a couple of other things that are worth noting. So relatively uncommon but important to be aware of is the possibility of impotence. There is a mood change that some people notice. So depression there could be some fatigue or, you know, drowsiness and then people who have other medical conditions need to be aware of the potential impact of beta blockers on their conditions. So for example, people who have a condition called myasthenia gravis should not take beta blockers. And then the other thing that is worth noting for those who have diabetes is that beta blockers can mask the symptoms of hypoglycemia, so low blood sugar. So for those who have diabetes, where their blood sugar fluctuates quite a bit, especially on the lower side, this could be dangerous, even life-threatening. So, fortunately, in young healthy adults, this is not so much of an issue but, in those who are older or have these conditions such as diabetes or mice to me gravis, beta blockers are not an ideal choice, and, indeed, sometimes even contraindicated which means they should not be used at all.
Now, for those who are taking them, how can you minimize the side effects of the beta blockers? Traditionally what is taught is what’s called digital punctal occlusion in which you place the drops in your eyes, close your eyes lightly and then place your fingers right where the eyelids come together centrally and press in. So you feel a little notch and you just press in on that notch. Unfortunately, many people perform this incorrectly and essentially just put their fingers on the tips of the bridge of their nose and that’s not effective. You need to actually get it where the drainage system is which is in the eyelids where they come together. Now, there’s a recent study that suggests that an easier method may be even more effective and that’s to just simply take a tissue, ball it up after you’ve put the eye drop in and push it right here in the corner where the eyelids come together toward the nose. That’s much easier and as long as you’ve got tissue around works really well, then there’s also the option of using an eye drop applicator. Most bottles of eye drop medications have more medication in the individual drop than you need, so you end up with it running down through your nasal lacrimal duct into your sinus back to your throat and that’s how it gets into the systemic system into the body. So, if you put in less than a full eye drop, that will also help.
Well, how do you put in less than a full eye drop? There are drop applicators that you can purchase. They tend to be very inexpensive. There’s one available through amazon.com, for example, called the Simply Touch that I recommend to my patients frequently because it just works so well. It’s inexpensive and, actually, the other benefit is that if you use less drops, you end up extending the time that you will have drops in the bottle. And, there is an issue with the bottles not necessarily having enough drops to last for an entire month. So, when might the beta blockers be prescribed? They are very commonly prescribed as one of the first two medications for patients. With newly diagnosed glaucoma, the prostaglandin analog class is pretty much neck and neck with the beta blockers and then, of course, there’s a question of, ‘Well, how much do they cost?’ Fortunately beta blockers as a generic version of timol is probably the most covered medication in glaucoma. And, one of the medications that both Target and Walmart have for under 10, basically no matter what your insurance no matter where your pharmacy is. If you’re paying more than 25 dollars for generic timolol, you’re getting ripped off. So find another pharmacy. Now, branded beta blockers, such as beta mall or ocados, which is the preservative free version, can be very expensive. They can be over a hundred dollars. They’re not always covered by insurance. And so, you know, cost can be an issue there. What I recommend is that if you are going to be prescribed a branded version and your physician thinks that you need that branded version and it’s not covered, I generally recommend a website called Goodrx, g-o-o-d-r-x. I’ll have the link below the video which shows you where you can get really good cash prices on medications. A quick note about preservative free ocudose. In general, I do prefer preservative-free topical medications when available and affordable because the most common preservative in eye drops back then, zeliconium chloride, is the full name. It can be damaging to the epithelium, the surface of the eye with chronic use. And there is some evidence that it can be toxic to the trabecular meshwork which is what we’re trying to treat because most open-angle glaucoma has its source or problem at the trabecular meshwork.
So, in any case, another video that’s gone longer than anticipated but this is all I think is important information for those who are prescribed beta blockers or considering them as an option.
So, in summary, the beta blockers have been around a long time. They’ve got a good track record of working well. They’re easy to use and that you only need to use them in the morning. They’re available both generically and with brand. And, you know, for the right person who is healthy and doesn’t have the conditions I spoke about and is using some form to reduce the amount of systemic absorption, it can be a very effective good value and well tolerated glaucoma medication.
David Richardson, MD
Medical Director, San Marino Eye
David Richardson, M.D. is recognized as one of the top cataract and glaucoma surgeons in the US and is among an elite group of glaucoma surgeons in the country performing the highly specialized canaloplasty procedure. Morever, Dr. Richardson is one of only a few surgeons in the greater Los Angeles area that performs MicroPulse P3™ “Cyclophotocoagulation” (MP3) glaucoma laser surgery. Dr. Richardson graduated Magna Cum Laude from the University of Southern California and earned his Medical Degree from Harvard Medical School. He completed his ophthalmology residency at the LAC+USC Medical Center/ Doheny Eye Institute. Dr. Richardson is also an Ambassador of Glaucoma Research Foundation.