Pharms Flashcards
Diagnostic agents
- Fluorescein
- Topical anaesthetics: proxymetacaine, benoxinate, tetracaine.
- Mydriatics and cyclopegics
Parasympathetic: Cyclopentolate, Tropicamide, Atropine
Sympathetic: phenylephrine HCl 2,5%.
Ocular side effects of Corticosteroids
- Posterior subcapsular cataracts.
2. Glaucoma.
Ocular side effects of Chloroquine
- Corneal deposits: Reversible and usually asymptomatic, but may cause photophobia or glare.
- Maculopathy: Dose related and initially asymptomatic, but on prolonged exposure it becomes progressive and irreversible, and produces a decrease in visual acuity.
Ocular side effects of Digitalis
- Dull vision
- Chromatopsia (abnormal colour vision).
- Ocular toxicity occurs with high doses, and classically everything appears yellow to the patient, although other colour aberrations may occur.
Ocular side effects of Phenytoin
Indication: Epilepsy and trigeminal neuralgia.
- Cerebellovestibular effects: Horizontal nystagmus in lateral gaze, vertical nystagmus in upward gaze, vertigo, ataxia
- Ophthalmoplegia: > blood levels may produce diplopia.
Ocular side effects of Ethambutol
Indication: TB.
- Optic neuropathy: 1 month of starting treatment. May be slow recovery or may be irreversible.
10 mg/kg/day - 1% probability
25 mg/kg/day - 5% probability
50 mg/kg/day - 15% probability
Ocular side effects of Phenothiazines
- Chlorpromazine:
- reversible punctate corneal epithelial opacities
- irreversible lenticular opacities. - Thioridazine:
- pigmentary retinopathy that can resemble retinitis pigmentosa.> l000 mg/day.
FLUORESCEIN
Characteristics:
- A nonirritating, water soluble, orange dye
- fluoresces bright yellow-green under cobalt blue light.
MOA:
- stains collagen and mucus.
Indication:
- Corneal damage: only stain if epithelial cell layers absent and underlying basement membrane or stroma is exposed.
Contraindication:
- soft contact lenses are in the eye – it stains the contact lenses
TOPICAL ANAESTHETICS
Examples: proxymetacaine, benoxinate, tetracaine.
Indication:
- Assist in examining painful corneal conditions
- Schiøtz tonometry
- Foreign body removal from the cornea or conjunctiva.
MOA:
- 15 min
- anaesthetise cornea and conjunctiva
Contraindications:
- Never prescribe to take home–> Corneal damage if longterm use
Side effects:
- Seldom local or systemic allergic reactions
- Dont prescribe home–> Corneal damage: toxic to the epithelium–> Inhibit mitosis and cell migration
MYDRIATICS & CYCLOPLEGICS:
PARASYMPATHOLYTICS (ANTICHOLINERGICS)
PARASYMPATHOLYTICS (ANTICHOLINERGICS)
Examples: Cyclopentolate, Tropicamide, Atropine
Indication: According to time of action
• Atropine: Hyphaema where total immobilisation of the iris is desired to prevent 2° haemorrhage and little tendency to form posterior synechiae.
• Cyclopentolate: anterior uveitis for pain relief, but where some movement of the pupil is desired as there is a strong tendency to form posterior synechiae. (Occasionally omit dose to allow pupil to constrict further and break incipient posterior synechiae)
• Tropicamide: Diagnostic purposes because of its short duration of action.
MOA:
- Cause paralysis of sphincter pupillae and the ciliary muscle.
- < duration of action and cycloplegic potency:
Atropine sulphate 0.5% or 1% (longest acting and most potent cycloplegic)
Cyclopentolate HCl 0.5%
Tropicamide 0.5% or 1% (shortest acting and weakest cycloplegic)
Side effects:
- nausea, vomiting
- pallor
- vasomotor disturbances.
Topical ocular agents
- Decongestants:
- Naphazoline HCl 0.12%,
- Phenylephrine HCl 0.12%
- Tetrahydrozaline HCl 0.05% - Antimicrobial agents:
- Sulphacetamide
- Neomycin
- gentamicin
- tobramycin
- trimethoprim
- chloramphenicol
- bacitracin + polymyxin B
- tetracycline
- various fluoroquinolones (ciprofloxacin and ofloxacin are 2nd generation agents; gatifloxacin and moxifloxacin are 4th generation agents). - Antivirals:
- Acyclovir - Antifungals
- Amphotericin B
- Natamycin. - NSAIDS
- indomethacin (Indocid®)
- Na diclofenac (Naclof®). - Corticosteroids
- prednisolone
- betamethasone
- dexamethasone
- fluoromethalone. - Antiallergy agents
- Levocabastine (Livostin®)
- Lodoxamide (Alomide®)
- Emedastine (Emadine®)
- Spaglumate (Naaxia®)
- Olopatidine (Patonol®)
- Epinastine HCl (Relestat®)
- Ketotifen (Zaditen®)
- Naphazoline (vasoconstrictor) and antazoline (anti-histamine) - (Antistin Privine® and Spersallerg®).
- Sodium chromoglycate 2% (Opticrom®) - Agents used in glucoma
- Cholinergic agonists:pilocarpine
- Adrenergic agonists: adrenaline, apraclonidine (Iopidine®), brimonodine (Alphagan®)
- Nonselective β-blockers: timolol maleate (Timoptol®), levobunolol (Betagan®)
- Cardioselective β-blockers: betaxolol (Betoptic®)
- Carbonic anhydrase inhibitors: acetazolamide, dorsolamide, brinzolamide.
- Prostaglandin agonists: latanoprost, bimatoprost, travoprost.
- hyperosmotic–> acute angle closure glaucoma - Artificial Tears:
- Cellulose derivates
(a) Hydroxypropylmethylcellulose (HPMC): IsoptoPlain®, Spersatears®, Viscotraan®.
(b) Carboxymethylcellulose: Refresh Liquigel®.
- Polyvinyl alcohol: Liquifilm®, Tears Plus®.
- Mucomimetics: HPMS plus Dextrane 70: Tears Naturale®.
- Carbomers: Viscotears®
- HP-Guar derivatives: Systane®
- Petrolatum ointments: Duratears®.
Decongestants
Examples:
Naphazoline HCl 0.12%, Phenylephrine HCl 0.12%, Tetrahydrozaline HCl 0.05%
Indications:
MOA:
- weak adrenergic–> vasoconstrictor
- make the eyes whiter
Contraindications:
- not used >4x daily
- not used > 3 or 4 days
- precipitate angle closure glaucoma due to mydriasis in predisposed patients.
Side effects:
- rebound vasodilation
worsening of redness
irritation.
Artificial tears
Examples:
- Cellulose derivates
(a) Hydroxypropylmethylcellulose (HPMC): IsoptoPlain®, Spersatears®, Viscotraan®.
(b) Carboxymethylcellulose: Refresh Liquigel®. - Polyvinyl alcohol: Liquifilm®, Tears Plus®.
- Mucomimetics: HPMS plus Dextrane 70: Tears Naturale®.
- Carbomers: Viscotears®
- HP-Guar derivatives: Systane®
- Petrolatum ointments: Duratears®.
Indications
- dry eyes
- Abnormal tear film
- Lacrimal gland abnormality
Side effects:
- preservative sensitivity
- irritation.
- Gels provide > relief, but interfere with vision –> @ night
- Ointments cause»_space; blurring vision–> only severe cases.
SYSTEMIC SIDE EFFECTS OF OCULAR MEDICATIONS: β-BLOCKERS
AGENTS USED IN GLAUCOMA
- Bronchospasm: Avoid in asthma and COAD.
- Aggravate cardiac conduction defects and cardiac failure.
- Aggravate peripheral vascular disease.
- > blood glucose, so use with caution in DM
SYSTEMIC SIDE EFFECTS OF OCULAR MEDICATIONS: PARASYMPATHOMIMETICS (CHOLINERGIC AGONISTS)
AGENTS USED IN GLAUCOMA 5-10x the recommended dose 1. lacrimation 2. salivation 3. perspiration 4. nausea, vomiting 5. diarrhoea.
