ANS Drugs Used in Ophthamology

Question 0

Miosis (pupillary constriction): Agents

Answer 0

Parasympathomimetics
   - Direct-acting
         - Carbachol
         - Pilocarpine
   - Indirect- acting
         - Physostigmine
Utilized in glaucoma to facilitate outflow of aqueous humor

Question 1

Mydriasis occurrence (pupillary dilation)

Answer 1

Cholinergic (parasympathetic) blocking agents (atropine)

Sympathomimetics (alph-adrenergic agonist)

Question 2

Glaucoma: Most common type of glaucoma

Answer 2

Open-angle glaucoma

Question 3

Aqueous humor: Secretion

Answer 3

Produced in ciliary body
Requires carbonic anhydrase
Secreted into posterior chamber of the eye
Circulates around the iris into the anterior chamber
Exits the anterior chamber via the trabecular meshwork and canal of Schlemm

Question 4

Primary open-angle glaucoma: Characteristics

Answer 4

Progressive optic nerve damage with eventual impairment of vision
Devoid of symptoms until significant and irreversible optic nerve injury has occurred

Question 5

Primary open-angle glaucoma: Risk factors

Answer 5

Elevation of intraocular pressure
African- American (3x more than whites)
Family history
Advancing age

Question 6

POAG: Goals of treatment

Answer 6

Directed at reducing elevated IOP
   - The IOP is a risk factor
       - Only modifiable risk factor
       - Can have glaucoma without elevated IOP
Can be lowered via
   - Facilitating aqueous humor outflow
   - Reducing AH production
Preferred route
   - Topical

Question 7

Glaucoma Drugs: First Line

Answer 7

Beta-adrenergic blocking agents
   - Timolol
Prostaglandin analogs
   - Latanoprost
Alpha-2 adrenergic agonists
   - Brimonidine

Question 8

Glaucoma: Autonomic drugs

Answer 8

Miotics (pilocarpine, physotigmine)

Question 9

Autonomic drugs: Miotics action

Answer 9

Decrease IOP by increasing outflow of aqueous humor
Alpha-adrenergic agonists and beta blockers decrease IOP
- Beta decrease production
- Alpha increase outflow

Question 10

Autonomic Drugs: Miotics: Acetazolamide

Answer 10

Inhibits the carbonic anhydrase and decreases formation of AH

Question 11

Cholinergic blocking agents (atropine)

Answer 11

Can increase IOP and should not be used except in single, small doses

Question 12

Angle-closure glaucoma: Precipitated

Answer 12

Displacement of the iris that prevents the exit of aqueous humor

Question 13

ACG: Other features

Answer 13

Develops rapidly: medical emergency

No treatment will result in irreversible loss of vision in 1-2 days

Question 14

ACG: Treatment

Answer 14

Laser iridotomy

Iridectomy

Question 15

Beta-adrenergic blocking agents

Answer 15

Timolol

Question 16

Timolol: Mechanism and Use

Answer 16

Lower IOP by decreasing production of AH
Used primarily for open-angle glaucoma
Initial therapy and maintenance therapy

Question 17

Timolol: Adverse effects

Answer 17

Local: minimal effects
Systemic: Heart and lungs if absorbed in sufficient amount (bradycardia, bronchospasm)
Asthma patients recommended to use cardioselective

Question 18

Protaglandin Analogs: Agent

Answer 18

Latanoprost

Question 19

Latanoprost: Mechanism

Answer 19

Lowers IOP
- Facilitates AH outflow
As or more effective than beta-blockers

Question 20

Latanoprost: Adverse effects

Answer 20

Can cause harmless brown pigmentation of the iris
Redness, irritation
Increased growth of eye lashes

Question 21

Alpha2-Adrenergic Agonists: Agents

Answer 21

Apraclonidine (short term therapy)

Brimonidine (First-line drug for long-term therapy)

Question 22

Alpha2- Adrenergic Agonists: Common side effects

Answer 22

Dry mouth, local burning and stinging, headache, blurred vision, foreign body sensation

Question 23

Pilocarpine: Mechanism

Answer 23

Direct-acting cholinergic agonist
   - Miosis
   - Contraction of the ciliary muscle
Increase in output
   - Realigns the angle of outflow

Question 24

Pilocarpine: Side-effects

Answer 24

Headache
- Based off of accommodation due to long period of contraction
Could produce muscarinic manifestations
SLUDGE

Question 25

Carbonic Anhydrase inhibitor: Drugs

Answer 25

Dorzolamide (Topical)
- Decreases IOP by decreasing AH
Acetazolamide
- Systemic CAI used for mountain sickness

Question 26

Cycloplegics and Mydriatics: Drugs

Answer 26

Cycloplegics
- Paralyze ciliary muscles
Mydriatics
- Dilate the pupil

Question 27

Cycloplegics and Mydriatics: Uses

Answer 27

Adjunct to measurement of refraction
Intraocular examination
Intraocular surgery
Treatment of anterior uveitis

Question 28

Cycloplegics and Mydriatics: Adverse Effects

Answer 28

Blurred vision and photophobia
Precipitation of angle-closure glaucoma
Anticholinergic effects