Ocular Pharm: L12: Other Oral and IV Drugs: Fluoroquinolones and CAIs

Question 1

Evolution of Fluoroquinolones

1. First Gen (1)
2. Second Gen (3)
3. Third Gen (1)
4. 4th Gen (2)
5. What improves in Later generations?

Answer 1

1. Nalidixic Acid
2. Ciprofloxacin, Ofloxacin, Norfloxacin
3. Levofloxacin*
4. Gemifloxacin, Moxifloxacin*
5. Improved POTENCY, Increased broadness of Activity (more Gram +) and Safety in later generations
   * = Most Frequently Used

Question 2

Resistant Organisms

1. Resistant Organisms have been found in what 4 CLASSES?
2. Mechanisms of Resistance
   a. PLASMID MEDIATED: What protein mutations?

b. Mutations in what 2 enzymes?
c. What’s impaired that causes resistance?

Answer 2

1. a. MRSA, Pseudomonas, Enterococci, Coagulase-Negative Staphylococci
2. a. Qnr Protein Mutations
   b. in Gyrase and Topoisomerase
   c. Impaired Entry and Enhanced Efflux of Drug

Question 3

Pharmacokinetics

Answer 3

*Listen to lecture to see what we need to know…

Question 4

Side Effects (1)

1. What are the Most frequent side effects?
2. What are the next most frequent?
3. What other ones are possible?
4. What are other ones?

Answer 4

1. GI (Nausea and vomiting, anorexia)
2. Nervous system (dizzy, hallucinations, delirium)
3. Peripheral Neuropathy, Rash and other allergic issues, Phototoxicity RxNs, Drug fever, Arthropathy (cartilage erosions), Tendinopathy and Tendon Rupture.
4. QT interval Prolonged and Arrhythmia, Transaminitis and Liver Failure, Hyper and Hypoglycemia (AVOID in DIABETICS), Hematologic,

RETINAL DETACHMENT (according to Canadian Study; However, Denmark Study said that Fluoroquinolones are not associated w/increased risk of Retinal Detachment)

Question 5

Drug Interactions

1. Reduced Absorption of what 5 things?
2. Impaired Elimination of what?
3. What may EXACERBATE CNS Effects?
4. fluoro’s can INTERACT with DRUGS that prolong what?
5. May effect Pharmacokinetics of what 2 drugs?

Answer 5

1. Antacids, Vitamins w/Zinc, Ferrous Sulfate, and Didanosine
2. of Methylxanthines
3. NSAIDs
4. that Prolong the QT interval
5. of Cyclosporine and Warfarin

Question 6

Issues w/Newer Agents

1. Grepafloxacin: Why was it withdrawn?
2. Trovafloxacin: Why was it withdrawn?
3. Gatifloxacin: Why was it withdrawn?
4. Gemifloxacin: What % of women under 40 develop a RASH when taking it for LONGER than SEVEN DAYS?

Answer 6

1. Adverse Cardiac Events
2. risk of Hepatic Toxicity
3. Increased Frequency of Hypoglycemia and Hyperglycemia compared to other marketed Fluoroquinolones
4. 14% *mainly avoid this by doing just a 5 day course of treatment

Question 7

General Guidelines for Use

1. What should be used for DEEP or SEVERE Ocular BACTERIAL INFECTIONS?
   a. What other situation?
2. Why do we have to be careful when using Fluoroquinolones?
3. Why do we have to be conservative in the use of these drugs?

Answer 7

1. Oral or IV Fluoroquinolones.
   a. or for bacterial infections that DONT RESPOND to OTHER ORAL TREATMENTS
2. they can cause serious side effects: (Avoid when CONTRAINDICATED (Arryhtmia’s). Monitor for Side Effects (liver function). Limit Duration of Use
3. Due to resistance already starting to develop. (Use an older class of antibiotic if that will work first…and make sure patient uses the ENTIRE Course of care)

Question 8

Bacterial Keratitis

1. What is it?
2. What will the patient have/feel?
3. Often Associated with what?
4. Main infecting organism in CL wearers that we’re wary of?

Answer 8

1. Focal, White Opacity in the Corneal Stroma; May have OVERLYING ULCER
2. Conj. Injection, FBS or Pain, Decrease VA, Photophobia, Discharge (Purulent or Mucopurulent)
3. CL Wear
4. Pseudomonas Aeruginosa.
   * Also, Staph Aureus and Epidermidis and Pneumoniae. Strep Viridians, Etc.

Question 9

Bacterial Keratitis Treatment

1. What 2 Topical Drugs can be used?
2. When should you use SYSTEMIC THERAPY?
   a. Why are Fluoroquinolones useful?
   b. Why do we use the newer agents?
3. What is the DOSAGE?

Answer 9

1. Topical Fluoroquinolones and Topical Fortified Antibiotics
2. When there is SCLERAL or INTRAOCULAR SPREAD of infection.
   a. Because Most of the common infecting bacteria are GRAM NEGATIVE
   b. it will DECREASE TREATMENT FAILURES due to resistance
3. 320-500 mg/kg po BID or QD, depending on the drug.

Question 10

Preseptal Celulitis

1. Pt may have a HISTORY of what 3 things?
2. What are the 3 common Symptoms?
3. May also have a MILD what?
4. Pt will NOT HAVE what?
5. Infecting Organism is usually what 3?

Answer 10

1. Abrasion, Insect Bites, or Sinusitis
2. Tenderness, Redness, Swelling of Eyelid and Periorbital Area
3. a MILD Fever
4. No Proptosis, Optic neuropathy, restriction of Eye movement, or pain w/Eye Movement
5. Staph Aureus, Strep, Haemophilus, Influenzae
   (Gram + and -)

Question 11

Preseptal Cellulitis Treatment: Mild

1. Augmentin
   a. Children dosage?
   b. Adults dosage?
2. What else can be given with similar dosing as Augmentin?
3. Another drug?
4. What drug can be given but is CI in children? (Dosage?)

Answer 11

1. a. 20-40 mg/kg/day po in 3 divided doses
   b. 400 mg po q8h for adults
2. Cefaclor, po
3. Trimethoprim/Sulfamethoxazole (Bactrim), po
4. Moxifloxacin (400 mg, po/iv qd)

Question 12

Preseptal Cellulitis Treatment Moderate or Severe

1. Who would be considered mod or severe?
2. What should you do?
   a. What should be given?

Answer 12

1. CHILD LESS THAN 5 YEARS OLD, who appears TOXIC, or a PATIENT who DOES NOT improve on ORAL Antibiotics
2. Admit to the hospital for IV Antibiotics.
   a. Ampicillin/Sulbactam (Unasyn), Ceftriaxone, Moxifloxacin, Vancomycin

Question 13

Traumatic Endophthalmitis

1. May be due to what?
2. Usual infecting organisms?

Answer 13

1. Occult or Missed IOFB

2. Bacillus sp., Staph Epidermidis, Strep sp., other Negative Bacteria

Question 14

Endophthalmitis Treatment

1. Treat what if necessary?
2. What Topical Antibiotics?
3. What 3 Systemic Antibiotics and Dosages?

Answer 14

1. Ruptured globe if necessary
2. Fortified Tobramycin q1h, alternating w/Fortified Cefazolin or Vancomycin Every HALF HOUR
3. a. Ciprofloxacin, 400 mg, iv, q12h
   b. Moxifloxacin, 400 mg, po, qd
   c. Cephazolin, 1g, iv, q48h

Question 15

CAIs: Acetazolamide

1. MOA?
2. Ocular Use?
3. Not generally used how to treat Glaucoma?

Answer 15

1. Blocks Carbonic Anhydrase in CB, Decreases Aq. Humor Production
2. Tx of ACUTE ANGLE CLOSURE
3. ORALLY

Question 16

CAIs: Acetazolamide: Adverse Effects

1. What are they? (5)
2. AVOID in Pt with what disease?

Answer 16

1. a. Metabolic Acidosis (mild)
   b. Potassium Depletion
   c. Kidney Stone Formation
   d. Drowsiness
   e. Paresthesia
2. with Liver disease

Question 17

CAIs: Acetazolamide: Major Interactions

1. Can interact with what 5 drugs?

Answer 17

1. Methenamine
2. NSAIDs
3. Pepto-Bismol
4. Topiramate
5. Salicylates

Question 18

Acute Angle Closure

1. Symptoms
   a. What happens RAPIDLY?
   b. What might they feel?
   c. What will happen in SEVERE Cases?
2. Signs
   a. Ciliary
   b. AC
   c. Pupil
   d. Iris BVs?
   e. IOP?

Answer 18

1. a. Rapidly Progressive UNILATERAL Vision Loss
   b. Periocular Pain and and Edema (may be mild)
   c. Nausea and Vomiting in Severe cases
2. a. Ciliary Flush
   b. Shallow AC w/Corneal Edema, Iridocorneal Contact, and/or Cells and Flare

c. Oval, Fixed Pupil
d. Dilated Iris BVs
e. SEVERELY ELEVATED IOP (50-100 mmHg)

Question 19

Acute Angle Closure Treatment

1. Option 1?
   a. Do this provided there’s no what?
2. Option 2
   a. Start with what?
   b. Then do what?
   c. If using DIAMOX SEQUELS for ORAL Dosing, give them what?
3. If there’s EMESIS, consider using ONLY what?

Answer 19

1. 500 mg iv and 500 mg po
   a. no emesis
2. a. 500 mg po
   b. then 125-250 mg po/iv q4h

c. give 500 mg BID
3. only IV dosing