Drugs to Treat Eye and Ear Disorders

Question 1

commonly used antibacterial agents for conjunctivitis

Answer 1

• Bacitracin
• erythromycin (Ilotycin)
• azithromycin (AzaSite)
• the fluoroquinolones

combination drugs
- Polytrim (polymyxin B/trimethoprim)
- Polysporin (polymyxin B/bacitracin)

Question 2

bacitracin pharmacodynamics - conjunctivitis

Answer 2

 Bacteriostatic
 Inhibits the incorporation of amino acids and nucleotides into the cell
 Active against gram positive and gram-negative organisms

Question 3

erythromycin pharmacodynamics - conjunctivitis

Answer 3

• A bacteriostatic macrolide antibiotic
• Binds to the 50S ribosomal subunit, inhibiting bacterial protein synthesis
• Active against gram positive organisms

Question 4

sulfacetamide - conjuntivitis

Answer 4

A synthetic sulfonamide that inhibits bacterial dihydrofolate synthetase

Question 5

tobramycin - conjunctivitis

Answer 5

A broad-spectrum aminoglycoside

Question 6

gentamicin - conjunctivitis

Answer 6

 A broad-spectrum antibiotic
 Active against gram-positive and gram-negative organisms

Question 7

azithromycin (AzaSite) - conjunctivitis

Answer 7

 A second-generation macrolide antibiotic
 Active against gram-positive organisms

Question 8

the fluoroquinolones - conjunctivitis

Answer 8

Bactericidal
- Inhibit DNA gyrase -> cell death

Question 9

polytrim pharmacodynamics

Answer 9

an ophthalmic antibacterial preparation that combines polymyxin B and trimethoprim

Polymyxin B
- Binds to cell membranes w/ high affinity, specifically the phospholipids in the cell wall
- increases cellular permeability
- Generally active against gram-negative bacteria

Trimethoprim
- Inhibits bacterial dihydrofolate reductase
- Has both gram-positive and gram-negative activity

Question 10

polysporin ophthalmic pharmacodynamics

Answer 10

Contains polymyxin B and bacitracin
- Activity against gram-positive and gram-negative

Question 11

common causative agent of conjunctivitis in newborns

Answer 11

ophthalmia neonatorum

Question 12

common causative agent of conjunctivitis in preschool children

Answer 12

bacterial conjunctivitis

Question 13

common causative agent of conjunctivitis in school children

Answer 13

viral etiology (adenovirus)

Question 14

common causative agent of conjunctivitis in adolescents and adults

Answer 14

N. gonorrhea needs to be excluded

Question 15

common causative agent of conjunctivitis in adults

Answer 15

viral or bacterial conjunctivitis

Question 16

Ophthalmia Neonatorum

Answer 16

Conjunctivitis occurring within the first 4 weeks of life
- Most common cause: chlamydia
- Most serious cause: gonococcal conjunctivitis
–> Concerns that the bacteria will cause blindness

Question 17

treatment for gonococcal conjunctivitis

Answer 17

IM ceftriaxone once
* If there are extraocular manifestations -> 7-day course of IM or IV ceftriaxone
* Prophylaxis is recommended as soon as possible after delivery -> erythromycin ointment 0.5%

Question 18

treatment for chlamydial conjunctivitis

Answer 18

Requires treatment with systemic erythromycin for 14 days or 3 days of azithromycin

Question 19

bacterial conjunctivitis

Answer 19

Considered a self-limited disease, but patients who receive topical antibiotic therapy have faster clinical improvement
- Most schools require treatment for the child to return to school

Question 20

uncomplicated conjunctivitis can be treated with:

Answer 20

• erythromycin ointment
• trimethoprim/polymyxin B (Polytrim)
• bacitracin/polymyxin B (Polysporin)
• fluoroquinolone drops

Question 21

conjunctivitis-otitis syndrome

Answer 21

The syndrome of conjunctivitis accompanied by otitis media
* predominantly occurs in children younger than age 6 years
- causative organisms: H. influenzae
- treatment: amoxicillin-clavulanate (Augmentin)