Allergic Eye Disease Flashcards
How do Mast Cell Stabilisers Work?
- Prevents degranulation of mast cells which prevents further histamine release
- Has no effect on current histamine
- Has a 2 week delay before therapeutic effect
Examples of Mast Cell Stabilisers
- Sodium cromoglicate
- Lodoxamide
Sodium Cromoglicate in Allergic Eye Disease
- Topical mast cell stabiliser
- Dose is 4x daily
- No cautions in topical use
- Contraindications only allergy
- Drops sting upon instillation
- Use in pregnancy when benefits outweigh risks, safe in breastfeeding
- Can be GSL, P or PoM
Sodium Cromoglicate GSL Preparations
- Entry level
- Opticrom
- Only licensed for seasonal conjunctivitis
- Not for use in those under 6 yrs
- Suggested to contact healthcare professional if symptoms do not resolve within 14 days
Sodium Cromoglicate P Preparations
- Entry level
- Optrex
- Only licensed for seasonal and perennial conjunctivitis
Sodium Cromoglicate PoM Preparations
- More scope for wider range of conditions
- Allergic conjunctivitis (acute and chronic)
- VKC
- CLAPC
Lodoxamide in Allergic Eye Disease
- IP Level
- 0.1% concentrations
- For all subtypes of allergic conjunctivitis
- Dose is 4x daily
- Contraindications are allergy
- Preferrable to avoid in pregnancy, caution in breastfeeding
When are Systemic Antihistamines Indicated?
- Indicated for both seasonal and perennial allergic conjunctivitis
- Particularly recommended if other systemic symptoms
- Specialists can use for long term management of AKC
Sedating Antihistamines
- Older class of drug
- Causes drowsiness
- No driving or operating heavy machinery
- Example drugs are chlorphenamine and clemastine
Non-Sedating Antihistamines
- Newer class of drug
- Less likely to induce drowsiness
- Longer half life when compared to older generation of drugs
- Example drugs are loratadine and cetirizine
Chlorpenamine in Allergic Eye Disease
- Indications: Hayfever, food allergy, drug reaction
- Dose 4mg every 4-6 hours (max 24mg in 24 hrs In adults)
- Cautions: Epilepsy, urinary retention, prostatic hypertrophy, ACG susceptibility
- Interact with other drugs with anticholinergic actions
- Contraindications: Hypersensitivity, use of MAOIs in previous 14 days
Loratadine in Allergic Eye Disease
- 10mg daily dose in adults
- Interact with other drugs with anticholingeric effects and avoid in combination with antidepressants
- Contraindications: Allergy
- Avoid in pregnancy and breastfeeding
Loratadine GSL/P Preparations Indications and Age
- Indicated for allergic rhinitis and hives
- Over age 2 yrs
Loratadine PoM Preparations
- Indicated for hayfever and hives
Chlorphenamine Side Effects
Drowsiness, HA, fatigue, dizziness
Loratadine Side Effects
Common: Drowsiness, nervousness
Uncommon: Appetite increase, HA, insomnia
Rare: Alopecia, dry mouth, dizziness
Topical Antihistamines
- IP Level
- Example is olopatidine
Olopatidine in Allergic Eye Disease
- IP level
- Anti-histamine and mast cell stabiliser, provides a few hours of instant relief
- Indications: Seasonal allergic Conjunctivitis (and other off label uses)
- Dose: 2x daily for upto 4 months
- Interactions: Any drug with anticholinergic actions
- Contraindications: Hypersensitivity
- Not recommended for pregnancy and breastfeeding
Topical Decongestants in Allergic Eye Disease
- Entry level
- Adrenergic alpha agonist to promote vasoconstriction and reduce eye irritation
- No effect on underlying cause
- Dose: 2x daily
- Naphazoline 0.1% (preserved)
- Contraindications: not used in under 12’s, not used for more than 7 days, excessive use (toxic reaction)
- Side Effects: Mydriasis
- Caution in those with CV disorders, arrhythmia, HBP and DM
