Drugs Used in Optometry Australia PDF

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Summary

A table breaking down the drugs used in optometry Australia including mechanism of action, indications, dosage and contraindications. ...

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KEY NOTES Bacterial conjunctivitis Tx:

Ocular Antibiotics Mechanism of Action of Antibacterial Drugs 1. Inhibit cell wall synthesis 2. Affect cytoplasmic membrane (increase permeability) 3. Affect protein synthesis 4. Affect folic acid 5. Affect DNA synthesis Drug Chloramphenicol 0.5% drops 1% ointment

Dose and notes Every qih, then every 2 hours for 2 days. Q.i.d. continue for 2 days after symptoms cleared – qid for 5 days for milder cases

(chlorsig)

Broad spectrum NOT GOOD FOR PSEUDOMONAS

Quinolones Ciprofloxacin Ofloxacin

Broadspectrum coverage Still good for Pseudomonas sp. – CL wearers Monotherapy for MK

Aminoglycosides

1-2 gtt q4h max 10 days

Gentamycin 0.3% (Genoptic)

Broadspectrum coverage- good for CL wearers and gram neg and staphylococci

Tobramycin 0.3% (tobrex)

Use fortied aminoglycoside with Cephalosporin for old Px with MK

Brolene Propamidine 0.1% drops 0.15% ointment

1-2 drops B.i.d-t.i.d no more than a week

Cephalosporin (cefazolin) 5% drops

1.

Chlorsig is broad spectrum and over the counter

2.

If CL wearer and pseudomonas suspected Mx as MK: o Quinolone (ciprofloxacin) Monotherapy o Aminoglycosides (tobrex, gentamycin)+ Cephalosporin  Cephalosporin is compound @ chemist and only lasts 4 days so new Rx is needed- too troublesome!!!

Mechanism of Action Inhibits peptidyltransferase activity of the 50S ribosomal subunit  inhibit mitochondrial membrane protein synthesis leading to suppression of mitochondrial respiration and ultimately cessation of cell proliferation Bacteriostatic

Use Blepharitis Conjunctivitis Chlamydial conj. Low grade peripheral keratitis Prophylactic Tx

Bacteriocidal Cirpo- gtt qid. In severe infetions every 2 hours for 2 days- max duration of use is 21 days Oflox – gtt every 2 hours for 2 days then qid. – max duration of use is 10 days Aminoclycoside: Causes incorrect reading of mRNA synthesis of non functional protein (at ribosome). Resistance becoming more common Bacteriocidal

For CL wearersPseudomonas and Microbial keratitis

Adverse Effects Gray syndrome: babies don’t have fully functioning liver enzymes Bone Marrow Aplasia: A hypersusceptibility reaction. Skin hypersensitivity ***not available in USA Itchying, burning, stinging, discomfort and photophobia

Contraindications Infants Pregnancy Lactation CYP450: can be interfered by due to inhibiting microsomal enzymes Oral Anti-coagulants pregnancy

CL wearers Blepharitis Conjunctivitis Corneal ulcers Microbial keratitis

Hypersensitivity, conjunctival toxicity after 1 week. External rash around the eye (lid itch, swelling) Delayed re-epithelialisation

Member of the aromatic diamidine group antiseptic – Bacteriostatic (antibacterial and acanthamoeba) Induces leakage of amino acids and inhibit oxygen uptake

Acanthameoba

Blurred vision, Eye pain and irritation Corneal keratopahty in prolonged treatment

Hypersensitivity CL’s use

Q1h Duotherapy with aminoglycoside Synthetic penicillin – must be compounded at chemist  only lasts 4 days

Inihbit cell wall synthesis B-lactam: bind to penicillin binding protein which catalyse cross-linking of cell wall components Bacteriocidal

CL wearersMicrobial keratitis

Vit K deficiency

Known allergy Haemophillia

Macrolides Azithromycin

1-2 drops bid for 3 days

Bacteriostatic

Tetracyclines ointment

Bid or qid continued for 2 days after symptoms have disapeared

Bac conjunctivitis Trachoma Influenza (viral conjuntivitis) Bac conjunctivitis

Tobrex has a secondary anti-inflammatory action  good for blepharitis!

< 8 years old

Ocular Antivirals Drug Acyclovir 3% (Zovirax) ointment

Use Topical: HSV epithelial and stromal keratitis Oral: reduce severity of acute symptoms and reduce recurrence of epithelial/ stromal HSV by 30/50%

Dose and Notes Ointment: 1cm 5x/day for 14 days then 3 days after recovered Oral: 800mg 5x/day for 7 days then 3 days after

Mechanism of Action Acyclovir triphosphate competitively inhibits viral DNA polymerase. When incorporated into viral DNA acts as chain terminator since it lacks deoxyribose 3’-OH end  no DNA synthesis

Side Effects Mild stinging Superficial punctate keratopathy

Contradictions Avoid CL use

MK Review peroid:  Next day  Day 3  Every 1-2 days until lesion gets better  Once a week for 2-3 weeks after recovery If by day 7 lesion has not altered, Px should be referred to an opthalmologist MK Antibiotic Tx Empirical:  Quinolone monotherapy (Ciprofloxacin 0.3%) OR  Cephalosporin + Aminoglycoside Cefazolin 5%+ Gentamicin 1.5%

Ocular Steroids Drug

Use

Penetration

Mechanism of Action

Side Effects

Contradictions

Prednisolone acetate 1% (PredForte)

Fluorometholone with acetate 1% (Flarex) Fluorometholone with alcohol 0.25% (FML Forte) Fluorometholone SUSPENSION 0.1% FML Dexamethasone sodium 0.1% (Maxidex) Hydrocortisone 0.5% or 1% ointment

Acute anterior uveitis Qih for 1 hr, then every one for 1 day. Qid for 1-2 days and taper gradually. Reduce by one drop every week (4 week taper) Post LASIK Sx to reduce graft rejection Iritis Inflammation and infection

Allergic conjunctivitis GPC, sterile infiltrates Episcleritis Dry eye Qid for 1 week then taper Treat short-term inflammatory eye conditions, conjunctivitis, iritis, uveitis, keratitis Tid for temporary relief of anterior blepharitis, seborrheic dermatitis

Best penetration into AC

Glucocorticoid inhibit the edema, fibrin deposition, capillary dilation, and phagocytic migration of the acute inflammatory response, as well as capillary proliferation, deposition of collagen, and scar formation.

Use for 18months  Posterior Subcapsular Cataract

Surface acting, 2.5x stronger potency then prednisolone

Corticosteroids  inhibit inflammatory response oedema, capillary dilation and proliferation, leukocyte migration and scar formation associated with inflammation

4 months  PSC

Surface acting

Work by induction of phosolipase A2 inhibitory proteins, these proteins control biosynthesis of mediators or inflammation such as prostaglins and leukotrienes by inhibiting the reliase of their precursor – arachionic acid.

Surface acting, low penetrance

High potency, good penetration Rapid acting- short duration

Corticosteroid  decrease inflammation 1. Decrease lymphocytes, monocytes ect 2. Inhibit synthesis of interleukins, cytokines 3. Stablise lysomal membranes

Viral Fungal Mycobacterium infectious Purulent conditions of the eye After FB removal Undiagnosed red eye Glaucoma – corticosteroids increase IOP Herpetic Keratitis Tuberculosis

Discomfort in eye, FB sensation

Ocular Penetrance (most to least): 1. Acetate 2. Alcohol 3. Phosphate

Anti Glaucoma Drug

Mechanism of Action

Dose and Notes

Side Effects

Contraindications

1 drop once a day in the evening

Prostagaladin Analogue:

Increase uveoscleral outflow (upregulation production of various metaloprotinases →

Stinging, burning Periorbital pigmentation

Inflammatory disease Hx of CMO HSV keratitis

Anti Glaucoma Drug

Mechanism of Action

Dorzolamide 2% (Trusopt)

Carbonic anhydrase inhibitor: Brinzolamide 1% (Azopt)

decrease aqueous production Decrease IOP 10 -20%

Acetazolamide 250mg (Diamox) tablet

Decrease IOP 20-30%

Dose and Notes

Side Effects

Contraindications

Monotherapy: gtt t.i.d Adjunctive therapy: bid (good adjunctive therapy to B-blocker) gtt t.i.d Better tolerance than dorzolamide due to more physiological pH

Ocular: Stinging/burning Hypersensitivity Irreversible corneal decompensation Corneal oedema, haze (children)

Ocular: Corneal endothelium compromise

Common: Paraesthesia of hands & feet Nausea vomiting, fatigue & weight loss Depression Uncommon: Bone marrow depression  aplastic anaemia Ocular: Browache Stinging/ irritation Ciliary spasm (myopia) Miosis Papillary block - advanced cataract Retinal detachment - high myopia Cataract –long term use Systemic (uncommon): Headache Dyspnea Bradycardia/arrhythmia Salivation, sweating Diarrhoea/vomiting GI disturbance

Hypersensitivity to sulfonamides Marked renal or hepatic problem Pregnancy

250mg Tablet: 1-4 times a day 500mg Capsule 1-2 times a day

Pilocarpine 1% (Pilopt)

Direct acting muscarinic agonist: act on mACh receptors  contaction ciliary muscle and sphincter papillae  open up spaces in TM and causes miosis  further opens up angle

Carbachol 1.5% (Isopto Crbachol)

Decrease IOP 20-25%

Cholinergic Agonist

gtt q.i.d for open angle 3 drops over 30 minutes for closed angle It has been shown to decrease uveoscleral outflow, which may have a significant clinical effect in the eye with compromised TM outflow Tid More potent than pilocarpine - may be used to control IOP where pilocarpine is ineffective or in cases of pilocarpine sensitivity

Systemic: Hypersensitivity to sulfonamides

Ocular: High myopia Cataracts Inflammation Infection Previous Hx of RD Neovascular & uveitic glaucoma – vasodilation & increase inflammation Px...