PHARMY

Question 1

Antiglaucoma drugs:

Answer 1

1. B-blockers: First line for POAG > and all others
   inhibit B-adrenergic receptors in ciliary body > decreased aqueous production
   Ocular iritation, corneal desens, DED, macular edema
   Bronchospasm, cough, arrythmia, headache, nausea
   Contra. chronic obstructive PD, asthma, Bradycardia
   
   1. Non-selective (B-1/2)
      
      1. Timolol/Levobunolol
         0.25% BID, IOP decreases 25%
   2. Selective (B-1)
      
      1. Betaxolol
         
         • Less side effect; less efficacy
2. Prost-analogues: All but uveitis glauc: Greater IOP reduction, causes inflammtion
   Prodrug metabolized by corneal esterase > binds PGF2a receptor on ciliary muscle > ECM remodeling/MMP regulation > increase uveoscleral outflow
   Iris heterochromia, lid pigmentation, lash lengthening, redness, SPEE
   Contra. Ocular inflammation (HSK), CMO, allergy
   1. Latanoprost (Xalantan)
   0.005% daily, IOP decreased 30%
   
   1. Bimatoprost (Lumigan): 0.03%
   2. Travoprost (Travatan): 0.004%
3. Adrenergic-agonist:
   Stimulate A-2 receptors > adenylate cyclase inhibition > decreased cMAP in ciliary cells > aqueous production loss
   Stimulation of A-1 receptor > vasoconstriction of CB vessels > reduced aqueous production
   
   • Photophobia, blur, stinging
   • Dry mouth, hypotension, fatigue
     
     1. Apraclonidine: selective A2 (weak A1)
        0.5% BID, IOP decrease 20%
        Causes tachyphylaxis
4. Carbonic anhydrase inhib: CA is critical for aqueous formation
   Decreases bicarbonate ion formation > reduced fluid transport in ciliary epith.
   Causes blood acidosis, renal stones, metalic taste, confusion
   Contra. Heart/kidney disease
   1. Acetazolamide (Diamox/Diazamide): IV for Rapid IOP decrease, oral otherwise
   250mg BID, 20% decrease by 4h
   500mg IV, 20% decrease by 30min
   
   1. Dorzolamide (trusopt): topical, fewer systemic affects
      2% 3/d, 20% IOP decrease
5. Hyperosmotics: ^Plasma osmolarity > fluid uptake from ocular tissue
   Nausea, heart faliure, confusion, kertoacidosis
   Contra. DM
   
   1. Glycerol: oral dose 4ml/kg
      20 onset, poor ocular penetration
   2. Mannitol: 20%
      Not contra. for renal faliure
6. Cholinergic agonist: Stimulate muscarinic receptors in CB > Miosis > TM opening > increased outflow
   Accomodative spasm, pupil block, cataract
   Contra. cataract, myopia, young Px
   
   1. Pilocarpine: 2% QID, 15% IOP decrease

Question 2

Acyclovir and ganciclovir:

Answer 2

Antiviral prodrug, metabolized by viral enzymes to acyclovir/ganciclovir triphosphate
1. Competes with dGTP for incorporation into viral DNA
2. Chain terminator for DNA formation / Faulty DNA replication
Viral enzymes have higher affinity for acyclovir than host cells
- HSV: 3% ointment 5/d (up to 10d)
- HSV: 400mg 5/d (up to 10d)
- HZO: 800mg 5/d (up to 10d)
Ganciclovir has high affinity for cyclomegalovirus enzymes, but also affects host cells moreso than acyclovir

Question 3

Prednisolone and Dexamethasone:

Answer 3

Cortico, lipophilic (^penetration)
1. Binds glucocorticoid receptors in cytoplasm
2. Pred.-GR complex moves to nucleus and regulates gene expression
1. Reduces cytokines (IL-1, TNF-a, INF-y)
2. Inhibits cyclooxygenase-2 expression > reduced mediator synthesis (prostaglandins)
3. Inhibits T/B cell proliferation
Dexamethasone (0.1%) has higher potency for faster response, but greater risk (^IOP more)
Same dosage and taper though, Pred 1% QID, or loading dose hourly 6h

Question 3

Cyclosporin:

Answer 3

Immunosuppressive, used when cortico. non-response or risk
Lipophilic ^Penetration
1. Binds cytoplasmic protein cyclophilin
2. CC complex inhibits calcineurin, which normally
1. Protein phosphate for T-cell activation
2. processes transcription factors for IL-2
Commercially used for organ transplant
Side effects:
- HT, kidney damage

Question 4

Antiglaucoma drugs:

Answer 4

1. B-blockers: First line for POAG > and all others
   inhibit B-adrenergic receptors in ciliary body > decreased aqueous production
   Ocular iritation, corneal desens, DED, macular edema
   Bronchospasm, cough, arrythmia, headache, nausea
   Contra. chronic obstructive PD, asthma, Bradycardia
   
   1. Non-selective (B-1/2)
      
      1. Timolol/Levobunolol
         0.25% BID, IOP decreases 25%
   2. Selective (B-1)
      
      1. Betaxolol
         
         • Less side effect; less efficacy
2. Prost-analogues: All but uveitis glauc: Greater IOP reduction, causes inflammtion
   Prodrug metabolized by corneal esterase > binds PGF2a receptor on ciliary muscle > ECM remodeling/MMP regulation > increase uveoscleral outflow
   Iris heterochromia, lid pigmentation, lash lengthening, redness, SPEE
   Contra. Ocular inflammation (HSK), CMO, allergy
   1. Latanoprost (Xalantan)
   0.005% daily, IOP decreased 30%
   
   1. Bimatoprost (Lumigan): 0.03%
   2. Travoprost (Travatan): 0.004%
3. Adrenergic-agonist:
   Stimulate A-2 receptors > adenylate cyclase inhibition > decreased cMAP in ciliary cells > aqueous production loss
   Stimulation of A-1 receptor > vasoconstriction of CB vessels > reduced aqueous production
   
   • Photophobia, blur, stinging
   • Dry mouth, hypotension, fatigue
     
     1. Apraclonidine: selective A2 (weak A1)
        0.5% BID, IOP decrease 20%
        Causes tachyphylaxis
4. Carbonic anhydrase inhib: CA is critical for aqueous formation
   Decreases bicarbonate ion formation > reduced fluid transport in ciliary epith.
   Causes blood acidosis, renal stones, metalic taste, confusion
   Contra. Heart/kidney disease
   1. Acetazolamide (Diamox/Diazamide): IV for Rapid IOP decrease, oral otherwise
   250mg BID, 20% decrease by 4h
   500mg IV, 20% decrease by 30min
   
   1. Dorzolamide (trusopt): topical, fewer systemic affects
      2% 3/d, 20% IOP decrease
5. Hyperosmotics: ^Plasma osmolarity > fluid uptake from ocular tissue
   Nausea, heart faliure, confusion, kertoacidosis
   Contra. DM
   
   1. Glycerol: oral dose 4ml/kg
      20 onset, poor ocular penetration
   2. Mannitol: 20%
      Not contra. for renal faliure (no renal metabolism)
6. Cholinergic agonist: Stimulate muscarinic receptors in CB > Miosis > TM opening > increased outflow
   Accomodative spasm, pupil block, cataract
   Contra. cataract, myopia, young Px
   
   1. Pilocarpine: 2% QID, 15% IOP decrease

Question 5

Chemotherapeutic agents topical:

Answer 5

Indicated for OSSN as corneal extension or contacting more than half the limbus
Mitomycin C (0.02%): inhibits DNA/protein synthesis, cell migration, ECM production
- causes hyperemia, punctate erosions, DED
5-fluorouracil (1%): inhibits thymidylate synthetase, DNA/RNA syntesis
- causes conj. hyperemia, lid erythema
Interferon a2b 1million IU/ml: anti-microbial
- causes SPEE, follicular conjunctivitis

Question 6

50S subunit drugs:

Answer 6

Antibacterial, binds 50s ribosomal subunit, inhibiting peptide formation
- Chloramphenicol
- Azithromycin
- Erythromycin .5%

Question 7

Quinolones:

Answer 7

BS antibacterial
Inhibition of topoiosomerase-2 (DNA gyrase) and topoisomerase 4 > transcription/replication loss
- Ciprofloxacin .3%
- Ofloxacin .3%
- moxifloxacin

Question 8

30S subunit drugs:

Answer 8

Aminoglycosides: bactericidal via faulty protein synthesis
- Gentamicin: Gram-ve species
- Tobramycin .3%
- Framycetin
Tetracyclines: Bacteriostatic via inhibited protein synthesis
- Tetracycline: alternate trachoma management
- Doxycycline

Question 9

NSAIDs

Answer 9

COX enzyme inhibition > loss of prostaglandin synthesis
- Ketorolac .5 QID
- Diclofenac .1%