4 - Anesthetics, Antihistamines

Question 1

Topical ocular anesthetics

• MOA
• structure
• amide vs ester

Answer 1

Block nerve conduction and change membrane permeability by stopping influx of Na+ ions into nerve cytoplasm
-w/o Na+ entry, nerve cannot depol

Aromatic residue = lipophilic
Intermediate chain = incr length + potency
Amino group = hydrophilic

Bond b/w intermediate chain + amino group = amide vs ester

• A: LONGER duration of action, metabolized by LIVER, LESS toxic, LIDOCAINE
• E: shorter duration of action, metabolized locally, ALL TOPICALS, INCL OCULAR (gtts)

Question 2

Proparacaine

• type of drug
• SE

Answer 2

Topical anesthetic (ester)

Corneal melting

Question 3

Benoxinate

• type of drug
• use
• SE

Answer 3

Topical anesthetic (ester)

Fluoress = benoxinate + fluorescein

Corneal melting

Question 4

Antihistamines

-MOA

Answer 4

Block type 1 HS reactions = minimize red/watery/itchy effects

• block cell receptors
• do NOT prevent release of histamine from mast cells and basophils

Question 5

Emedastine

• type of drug
• use

Answer 5

H1 antihistamine

In combination with a vasoconstrictor agent (e.g. Naphcon A) for mild-mod allergic conj-itis

Question 6

Cromolyn sodium

• type of drug
• MOA
• use

Answer 6

Mast cell stabilizer

Acts on exposed mast cells to inhibit degranulation upon reexposure to Ag: stabilizes membrane, PREVENTING Ca2+ INFLUX, and degranulation

Chronic allergic conj-itis: effects begin days-weeks after starting
Vernal conj-itis or atopic keratoconj-itis

Question 7

Lodoxamide

• type of drug
• MOA
• use

Answer 7

Mast cell stabilizer

Acts on exposed mast cells to inhibit degranulation upon reexposure to Ag: stabilizes membrane, PREVENTING Ca2+ INFLUX, and degranulation

Chronic allergic conj-itis: effects begin days-weeks after starting
Vernal conj-itis or atopic keratoconj-itis

Question 8

Pemirolast

• type of drug
• MOA
• use

Answer 8

Mast cell stabilizer

Acts on exposed mast cells to inhibit degranulation upon reexposure to Ag: stabilizes membrane, PREVENTING Ca2+ INFLUX, and degranulation

Chronic allergic conj-itis: effects begin days-weeks after starting
Vernal conj-itis or atopic keratoconj-itis

Question 9

Nedocromil

• type of drug
• MOA
• use

Answer 9

Mast cell stabilizer

Acts on exposed mast cells to inhibit degranulation upon reexposure to Ag: stabilizes membrane, PREVENTING Ca2+ INFLUX, and degranulation

Chronic allergic conj-itis: effects begin days-weeks after starting
Vernal conj-itis or atopic keratoconj-itis

Question 10

Bepotastine

• type of drug
• use

Answer 10

Mast cell stabilizer + Antihistamine

Long-term and acute allergic symptoms

Question 11

Epinastine

• type of drug
• use

Answer 11

Mast cell stabilizer + Antihistamine

Long-term and acute allergic symptoms

Question 12

Olopatadine

• type of drug
• use
• 0.10% vs 0.20%

Answer 12

Mast cell stabilizer + Antihistamine

Long-term and acute allergic symptoms

0. 10% = patanol
1. 20% = pataday

Question 13

Ketotifen

• type of drug
• use

Answer 13

Mast cell stabilizer + Antihistamine

Long-term and acute allergic symptoms

Question 14

Azelastine

• type of drug
• use

Answer 14

Mast cell stabilizer + Antihistamine

Long-term and acute allergic symptoms