shift is wild

Pharmacology · chapter 38 · Ophthalmic Drugs

Antiglaucoma Drugs

The 14 things this section of the textbook says that you are most likely to be asked about — quoted word for word, not retold. Then 6 practice questions with the reasoning.

Skip to the questions ↓

Key points

  1. IOP is the only modifiable risk

    Treatment of POAG focuses on reducing elevated IOP, the only risk factor that can be modified. Although no cure exists, reducing IOP can slow or even cease disease progression.

  2. First-line and second-line classes

    First-line drugs belong to three classes: beta-adrenergic blockers (beta blockers), alpha-2 adrenergic agonists, and prostaglandin analogs. Carbonic anhydrase inhibitors are considered second-line drugs.

  3. Angle-closure glaucoma is an emergency

    The client will complain of severe ocular pain and headache. Permanent vision loss may occur within 24–48 hours if left untreated.

  4. Why clients stop their drops

    These include the asymptomatic nature of the condition such that clients may feel drug therapy is unnecessary, frequent dosing intervals, multiple drugs to administer, and age-related issues (see the box below).

  5. Beta blocker contraindications

    They also are contraindicated in clients with sinus bradycardia, second- or third-degree AV block, cardiogenic shock, or severe heart failure.

  6. Occlude the medial canthus

    Although there is less concern about systemic effects when using beta blockers topically, some systemic absorption can occur when direct pressure is not applied to the medial canthus to occlude the nasolacrimal sac.

  7. Systemic beta blocker effects

    If adequate amounts of drug reach the circulation, the client may experience some systemic adverse effects. These effects may include bradycardia, hypotension, heart block, or worsening of heart failure.

  8. Timolol and lung disease

    Dyspnea and bronchospasm can occur in clients with severe respiratory conditions like chronic obstructive pulmonary diseases (COPD) and asthma who are taking a nonselective beta blocker (timolol) but are less likely to occur with cardioselective agents (betaxolol).

  9. Masked hypoglycemia

    Because of the potential effect on heart rate, beta blockers may mask the symptoms of hypoglycemia in clients with diabetes (DailyMed, Timolol, 2023).

  10. Sulfonamide allergy and carbonic anhydrase inhibitors

    Clients with sulfonamide hypersensitivity can experience severe or even fatal reactions, such as Stevens–Johnson syndrome, toxic epidermal necrolysis, hepatic necrosis, aplastic anemia, or agranulocytosis.

  11. Prostaglandin analogues and cardiac clients

    Prostaglandin analogues are considered first-line agents for glaucoma, especially in clients with cardiac conditions.

  12. Iris darkening is usually permanent

    Be certain the client is aware that the hyperpigmentation of the iris is usually permanent, but the darkened skin of the eyelids more than likely will resolve.

  13. Why prostaglandins are given at bedtime

    Administer the medication at bedtime as ocular pressure is typically highest in the morning, so usage at night is a timely intervention to address an expected higher ocular pressure by morning.

  14. Brimonidine and young children

    Brimonidine is contraindicated in those under age 2 because they are at a higher risk of CNS depression.

Terms to know

Ocular hyperemia
The most common adverse effect is ocular hyperemia, which is engorgement of ocular blood vessels.
Carbonic anhydrase
Carbonic anhydrase is an enzyme found in many tissues of the body, including the eye.
Corneal verticillata
Corneal verticillata (gray-brown opacities) were noted to develop at 4 weeks of therapy.

Practice questions

Stuck on select-all-that-apply? How to take them one option at a time.

The graded version needs JavaScript. Every question is below anyway, with the answer and why.

Every question here, with the answer

  1. A client with open-angle glaucoma is prescribed timolol eye drops. Which history finding should the nurse report before the first dose?

    1. Second-degree AV block
    2. Seasonal allergies
    3. Myopia
    4. Recent cataract surgery on the other eye

    Answer: Second-degree AV block

    Ocular beta blockers are contraindicated in sinus bradycardia, second- or third-degree AV block, cardiogenic shock and severe heart failure, because enough drug can be absorbed to cause bradycardia and heart block. The other findings are not listed contraindications.

  2. A client with asthma needs a beta blocker eye drop for glaucoma. Which statement reflects the section?

    1. Beta blocker eye drops never reach the lungs.
    2. Bronchospasm is less likely with a cardioselective agent such as betaxolol.
    3. Asthma is only a concern with prostaglandin analogues.
    4. Timolol is preferred because it is nonselective.

    Answer: Bronchospasm is less likely with a cardioselective agent such as betaxolol.

    Dyspnea and bronchospasm can occur in clients with COPD or asthma taking nonselective timolol but are less likely with cardioselective betaxolol. Systemic absorption can occur, so the drops can affect the lungs.

  3. A client asks why latanoprost must be taken at bedtime rather than in the morning. What is the best explanation?

    1. Eye pressure is typically highest in the morning, so a night dose targets it.
    2. It must be taken on an empty stomach.
    3. It causes drowsiness.
    4. It only works in the dark.

    Answer: Eye pressure is typically highest in the morning, so a night dose targets it.

    Prostaglandin analogues are given at bedtime because ocular pressure is typically highest in the morning, so the night dose addresses the expected rise. The other reasons are not given in the section.

  4. A client is starting latanoprost for primary open-angle glaucoma. Which information should the nurse include? Select all that apply.

    1. Darkened eyelid skin will likely resolve.
    2. Follow-up pressure checks are no longer needed once drops start.
    3. Remove contact lenses and wait 15 minutes after the drop before reinserting.
    4. The iris may darken, and this change is usually permanent.
    5. Eyelashes may become longer.

    Answer: Darkened eyelid skin will likely resolve., Remove contact lenses and wait 15 minutes after the drop before reinserting., The iris may darken, and this change is usually permanent., Eyelashes may become longer.

    Iris hyperpigmentation is usually permanent, eyelid darkening usually resolves, eyelashes may lengthen, and contact lenses should be out during and 15 minutes after administration. Clients should not skip follow-up IOP measurements.

  5. An older adult with diabetes and heart failure is prescribed timolol eye drops. Which nursing actions are appropriate? Select all that apply.

    1. Monitor heart rate and rhythm.
    2. Monitor for signs of hypoglycemia.
    3. Teach the client to press on the inner corner of the eye after instilling.
    4. Teach the client to change positions slowly.
    5. Tell the client that eye drops cannot affect the heart.

    Answer: Monitor heart rate and rhythm., Monitor for signs of hypoglycemia., Teach the client to press on the inner corner of the eye after instilling., Teach the client to change positions slowly.

    Timolol can be absorbed systemically, causing bradycardia and worsening heart failure, and can mask hypoglycemia; occluding the inner canthus limits absorption, and slow position changes reduce falls. The drops can affect the heart, so the last statement is wrong.

  6. Dorzolamide eye drops are prescribed for a client. Which allergy in the client's history is most important to report?

    1. Shellfish allergy
    2. Latex allergy
    3. Sulfonamide allergy
    4. Pollen allergy

    Answer: Sulfonamide allergy

    Clients with sulfonamide hypersensitivity can have severe or fatal reactions to carbonic anhydrase inhibitors, and allergy to sulfonamides is a contraindication for dorzolamide. The other allergies are not mentioned for this drug.

Where every quote comes from

Section 38.4 Antiglaucoma Drugs of Pharmacology for Nurses by Tina Barbour-Taylor, Leah Mueller (Sabato), Donna Paris, Dorie Weaver, OpenStax, 2024. Read the whole section free at openstax.org.

The textbook is licensed under CC BY-NC-SA 4.0. This page quotes it word for word and adds the headings, the order and the practice questions; references to the book's figures and stray spaces left by its formatting are removed. The page is shared under the same licence. Nothing here is sold.