Okay, in this video we are going to talk about medications that are used for glaucoma, starting
with a topical beta-blocker which is timolol. So timolol is used to treat primarily
open-angle glaucoma. It is a nonselective beta-blocker, so basically
it decreases the aqueous humor production in the eye which helps to lower intraocular pressure.
In terms of side effects, they're usually pretty mild. It
can cause some temporary stinging in the eye. When your patient is getting this medication,
you want to advise them not to touch the applicator to the eye. And then after they put
the drops in, they want to hold gentle pressure to the nasolacrimal duct or puncta for about one
minute to help prevent systemic absorption. So with systemic absorption, you would
expect some of the side effects that we see with nonselective beta-blockers, so this can include
hypotension, bronchoconstriction as well as bradycardia. As long as they kind of hold
pressure there and don't overdo it on the drops, they should not get those systemic side effects.
Also, keep in mind that the normal intraocular pressure that we want to see in patients is
between 10 and 21 mmHg, so that is the goal. The way I remember this medication is that Tim,
some little kid named Tim, little bully, stuck his finger in my eye and he laughed out loud,
so timolol. And that's how I remember that timolol is for my
eye and it is used to treat open-angle glaucoma. Alright, now we're going to talk about a carbonic
anhydrase inhibitor which is acetazolamide. Acetazolamide can be used to treat glaucoma
as well as heart failure and altitude sickness. So my somewhat lame tip for remembering what
this medication is for if you look at the word acetazolamide, it looks like I can see a zoo.
And I can see that zoo because my glaucoma is fixed thanks to acetazolamide. So that's all
I've got here. If you have another tip then definitely leave it here in the comments.
So acetazolamide inhibits carbonic anhydrase in the eye which decreases
aqueous humor production and helps to lower the intraocular pressure. It also
inhibits carbonic anhydrase in the kidneys which causes increased excretion of sodium, potassium,
bicarb, and water. So it acts as a diuretic as well, which is why it's used for heart failure.
In terms of side effects, flu-like symptoms are very common with this class of medication
in addition to GI upset. And then electrolyte imbalances are
also a risk because we're causing that excretion of sodium and potassium that
can really mess with those electrolyte levels. Another side effect is hyperchloremic acidosis
because we're getting rid of bicarb as well, so that can cause acidosis.
So when we are giving a patient acetazolamide, we're definitely going to want to monitor their
electrolyte levels and their acid-base balance. Keep in mind that our goal for
intraocular pressure is between 10 and 21 mmHg. And we should administer this medication with
food to help prevent GI upset, which is a common side effect with this medication.
Alright. Let's now talk about a direct-acting cholinergic medication used for glaucoma.
Medications that fall within this class include pilocarpine as well as acetylcholine.
These medications are used for open-angle glaucoma.
They work to decrease intraocular pressure by improving aqueous humor outflow.
Side effects may include blurred vision, some stinging, as well as eye pain.
The way I remember pilocarpine is that it kind of looks like pile o' crap. So I can see your big ole
pile o' crap because my glaucoma's been fixed, thanks to this medication! So that's my little
weirdo hint for remembering this medication. Again, you want to teach your patient not to
touch the applicator to their eye, and they should hold pressure to that nasolacrimal duct for a
minute to help prevent systemic absorption. Alright. Now let's talk about prostaglandin
agonists, which include medications such as travoprost and latanoprost. Both of
these end in that -prost at the end. They're used for open angle glaucoma.
They help to reduce intraocular pressure by improving the outflow of aqueous humor.
Side effects can include stinging, which is really common across all of these topical
anti-glaucoma agents, but in addition, this particular medication can cause eyelash growth,
which is kind of awesome, right? I think this is the only med I can think of that has a really
great side effect that you can look forward to. But it can also cause eye color change due
to an increase in iris pigmentation, which may not be something you want.
So my tip for this class of medication, because they end in -prost, prost means cheers in German,
so let's raise our glasses and say "prost" because our glaucoma is fixed, and we have
longer eyelashes because of this little awesome side effect that this class of medication carries.
Keep in mind, we want to do our same teaching that we did with our other anti-glaucoma
agents in terms of not touching the eye with the applicator, monitoring the IOP,
which should be between 10 and 21 mmHg. Okay. The last anti-glaucoma agent
that I want to go over here is a sympathomimetic named brimonidine.
Brimonidine is used for open angle glaucoma. It helps to reduce intraocular pressure
by decreasing production of aqueous humor and also improving aqueous humor outflow.
Side effects include stinging, which is the same thing we've seen with all of these
topical anti-glaucoma agents. In addition, eye pain and drowsiness are possible side effects.
And again, you're going to want to do the same teaching for your patient in
terms of not touching the applicator to the eye, holding pressure at the lacrimal
duct after installation of the eyedrops for about a minute, and then you'll want
to keep an eye on intraocular pressure. It should be somewhere between 10 and 21 mmHg.
So that is it for our anti-glaucoma agents. In my next video, we will get into other nervous system
medications for disorders such as Alzheimer's and Parkinson's disease, so hang in there with me!