Glaucoma drugs Flashcards Preview

Brain and Behavior Drugs > Glaucoma drugs > Flashcards

Flashcards in Glaucoma drugs Deck (24)
Loading flashcards...
1
Q

What causes open angle glaucoma?

A

Caused by clogging of the trabecular
meshwork with decreased drainage of the aqueous humor.
Often undetected by patients until it is advanced, because it is
not painful. Causes elevated eye pressures, optic nerve
atrophy, and decreased vision once disease is advanced.

2
Q

What causes closed angle (acute) glaucoma?

A

A MEDICAL EMERGENCY. Patients can lose all vision in the eye within hours. Most common
mechanism is a pupillary block. The lens is attached to the iris, and pushes the iris anteriorly, which closes the angle between the
iris and the cornea. As the iris-corneal angle closes, the trabecular meshwork gets blocked. With no exit pathway, fluid builds up in
the chambers and creates a pressure gradient rapidly and acutely, which then damages the optic nerve.

Presentation: Acute eye pain, red eye, poorly reactive pupil, seeing halos, Increased Intra-Ocular Pressure (IOP), N/V

3
Q

What are the prostaglandin analogues?

A

Latanaprost, travaprost, bimatoprost, unoprostone.

“Prost” drugs

4
Q

What is MOA of prostaglandin analogues?

A
Lower IOP by increasing the
rate of fluid outflow from the
eye by increasing uveoscleral
outflow (space between
choroid and sclera)
- Increases the rate of fluid
outflow from traditional
meshwork outflow
5
Q

Prostaglandin analogues: Indications

A
Can be used with all glaucomas
(with rare exceptions).
Contraindicated with herpes keratitis
(viral infection of the eye caused by
HSV; causes rare inflammatory
glaucoma).
6
Q

Prostaglandin analogues: Side Effects

A
  • Ocular irritation and conjunctival injection
  • Increased iris and periocular skin pigmentation
    with longer. Thicker eyelashes

POSSIBLY DANGEROUS:

  • Uveitis
  • Possible herpes activation
  • Cystoid macular edema
7
Q

What are beta-blockers used for glaucoma treatment?

A

Timolol (Non-selective), carteolol (non-selective), levobunolol (non-selective), metipranolol (non-selective), betaxolol (selective)

8
Q

Beta-blockers: MOA

A
All are eyedrops. Reduce IOP
by blocking beta-adrenergic
R’s within the ciliary body
epithelium to reduce the
production of aqueous fluid.
9
Q

Beta-blockers: Indications

A
All types of glaucoma.
Non-selectives are absolutely
contraindicated with asthma, COPD
and greater than 1st degree heart
block. 

All beta-blockers are
absolutely contraindicated with
CHF.

Relative contraindication with sinus
bradycardia, hypotension, hx of syncope, hx of life threatening
depression, brittle insulin dependent
diabetes, impotence.

10
Q

Beta-blockers: Side effects

A
  • Due to topical route: corneal toxicity and
    allergic reaction.
  • Non-selective (1st 4) can be absorbed
    systemically and have SE’s of
    SOB/bronchospasm/CHF; decreased
    libido/impotence’ arrhythmias, bradycardia;
    depression.

To reduce level of beta-blocker absorbed into systemic circulation, pts should be taught
nasolacrimal occlusion method of eye drop
application.

11
Q

What are the alpha-2-agonists?

A

Brimonidine and apraclonidine

12
Q

Alpha-2-agonists: MOA

A

Decrease IOP by: Lowering amount of aqueous fluid produced and increasing the
outflow through the
uveoscleral outflow
pathway.

13
Q

Alpha-2-agonists: Indications

A

Use brimonidine for all types of
glaucoma.
Use apraclonidine for IOP spikes
following laser surgery for glaucoma.

Contraindicated with MAO-inhibitor
use and for patients less than 2 yrs.

14
Q

Side effects of brimonidine?

A

Dry mouth, fatigue, ocular redness,

ocular irritation.

15
Q

Side effects of apraclonidine?

A

Severe allergic blepharitis,
tachyphyalaxis with chronic use, mydriasis, eyelid
retraction and conjunctival branching.

16
Q

Which drugs can cause systemic side effects?

A

Prostaglandin analogues, beta-blockers and CAIs can case systemic side effects

• α-2-agonists don’t have many systemic effects unless used chronically, but do drip into mouth -> dry mouth

17
Q

Which drugs reduce IOP by decreasing amt of aqueous fluid produced?

A

Beta-blockers and CAIs reduce IOP by reducing the amount of aqueous fluid produced

18
Q

Which drugs reduce IOP by increasing outflow of fluid from eye?

A

Prostaglandins reduce IOP by increasing the outflow of fluid from the eye

19
Q

Which drugs reduce production of aqueous fluid and increase outflow?

A

Alpha-2 agonist reduce the production of aqueous fluid AND increase the outflow

20
Q

What reaction does carbonic anhydrase catalyze?

A

Hydration of CO2 and dehydration of bicarbonate.

Parietal cells use CA to secrete stomach into acid.

Pancreatic duct cells use CA to secrete bicarbonate.

RBC convert CO2 to bicarbonate fro transport then back to CO2 to be exhaled by lungs using CA.

Renal tubules secrete H+ to maintain acid-base and fluid balance using CA.

Cells producing CSF, aqueous fluid in eye, endolymph of semicircular canals, cochlear duct, perilymph of scala vestibuli and scala tympnai all contain high levels of CA.

21
Q

What are the carbonic anhydrase inhibitors (CAIs)?

A

Dorzolamide (topical)
Brinzolamide (topical)
Acetazlamide (oral)
Methazolamide (oral)

22
Q

CAI: MOA

A

Inhibiting CA in ciliary body

epithelium. Decreases IOP.

23
Q

CAI: Indications

A

Acetazolamide was first CAI used,
the “prototype”, used as diuretic.

Has
remained in popular use worldwide
for effects on specific tissues as
described above, and today’s main
use is in the tx of glaucoma.
Used topically for all glaucomas.
Can be used orally for rapid
lowering of acute increases in IOP;
when a patient has poorly tolerated
other topical glaucoma medications

Absolute contraindication:
sulfonamide allergy, SCD, aplastic
anemia, thrombocytopenia

Relative contraindication: adrenal
insufficiency, hepatic failure, chronic
respiratory acidosis, renal failure,
metabolic acidosis, repeated kidney
stones.
24
Q

CAI: Side Effects

A

TOPICAL: Stinging, burning, redness /dermatitis / conjunctivitis, allergy, transient
myopia, metallic taste.

ORAL: Parasthesis, frequent urination,
metabolic acidosis, metallic taste.

These drugs are structurally similar to
sulfonamides – so if a patient has an allergy, they
should not take CAIs.