anti allergic drugs
DESCRIPTION
EDUCATIONTRANSCRIPT
ALLERGIC CONJUNCTIVITIS It is the inflammation of conjunctiva due
to reaction from allergy causing substances like pollen, dander , house dust e.t.c
Clinical classification Acute Allergic Conjunctivitis (AAC) Intermittent/Seasonal Allergic
Conjunctivitis (IAC/SAC) Persistent/Perennial Allergic
Conjunctivitis (PAC) Giant Papillary Conjunctivitis (GPC) Vernal Keratoconjunctivitis (VKC) Atopic Keratoconjunctivitis (AKC)
The milder forms of allergic eye diseases have fluctuating symptoms of itching, tearing, and swelling.
Chronic form of the disease give rise, in addition, to more severe symptoms including pain, visual loss from corneal scarring, cataract or glaucoma, and disfiguring skin and lid changes.
NON PHARMACOLOGICAL APPROACH Allergen avoidance including physical
barriers, eg, hat, sunglasses, allergen-impermeable pillow and mattress covers
Cold compresses
Preservative-free tears
Slide 6Modes and sites of action of allergic conjunctivitis therapies
Mast cell
B cell
T cell(mast cell) Eosinophil
IL-4
IL-3, -5
GM-CSF
VCAM-1
IgE
Immediate symptoms• Itch, redness, edema,chemotaxis, edema, vascular permeability•Sensitized nerves, enhanced pain, edema, redness
Chronic symptoms•cell destruction•disruption of ocular surface
HistamineLeukotrienesProstaglandins
Allergen
Allergen
avoidance
Immuno-therapy
AntihistaminesOlopatadine
Sodium cromoglycateOlopatadine
Steroids
Eosinophil and Neutrophil chemotactic factors:
Anti-IgE
ANTIHISTAMINICS Used during acute attacks
Topical antihistamines
Azelastine 0.05%, emedastine0.05%, levocabastine0.05% used 4 times a day
Topical antihistamine plus vasoconstrictor
antazoline-naphazoline , cetirizine-pseudoephedrine , pheniramine-naphazoline
Oral antihistamines - Less effective than topical therapies - unwanted effects of ‘dry eye’ - indicated for multiple allergic symptomatology - non-sedating oral antihistamines:
loratadine, fexofenadine, cetirizine
Side efffects Headache – most common Bad taste Blurred vision Burning or stinging Corneal infiltrates Dry eye Rhinitis sinusitis
Mast cell stabilizers They produce stabilization of mast cell
membrane & prevent its degranulation Takes days to weeks to reach its peak
efficacy – so not used in acute attacks Can be used for prophylaxsis
Disodium cromoglycolate 4% : QID
Nedocromil 2% : Twice daily
Lodoxamide 0.1% : Highly potent, rapid relief anti-eosinophilic effect
Pemirolast 0.1 % : Twice or four times daily dosing,
effective for itch
Side effects Burning , stinging and discomfort upon
installation Do not produce immediate relief of
symptoms Headache , rhinitis , cold & flu
symptoms
Dual-action antihistamine/mast cell stabilizer Have mast cell antagonism & H1 antagonism
Olopatadine 0.1% Highly effective, rapid onset & atleat 8 hrs of action . Used twice daily
Olopatidine 0.2% used once daily
Side effects - burning ,stinging , foreign body sensation , dry eye , hypermia , keratitis , eyelid edema , pruritis , asthenia , rhinitis , sinusitis
Ketotifen 0.025% twice daily
Side effects – conjunctival injection , headache , rhinitis
Azelastine0.05% Approved for itch
Non steroidal anti -inflammmatory drugs
Block the cyclo-oxygenase pathway, limiting production of prostaglandins and thromboxanes
Analgesic. Can be used for acute attacksCommon drugs used Diclofenac 0.1% Ketorolac 0.5% (Acular ) Ketorolac 0.4% (Acular LS), Ketorolac 0.45% (Acuvail )
Nepafenac 0.1% (Nevanac ) Bromfenac 0.09% SIDE EFFECTS
Persistent epithelial defect. Stromal infiltration. Ulceration. Thinning. Perforation.
Corticosteroids - topical Corticosteroids, the gold standard for
inflammation control, prevent the formation of arachidonic
acid, effectively block both the cyclooxygenase and lipoxygenase pathways
suppress inflammatory cell migration and fibroblast function and reduce capillary permeability
fluorometholone 0.1% , 0.25% loteprednol etabonate 0.5% , 0.2% prednisolone acetate 0.12% ,1% Dexamethasone phosphate 0.1%, Difluprednate 0.05% Rimexolone 1%
Side effects Ocular discomfort. Delayed epithelial healing. HSV flare up. Increase IOP. Posterior subcapsular cataract Ptosis Mydriasis.
Local injection. VKC. AKC.
Oral. For severe cases of AKC.
Cyclosporine Cyclosporine (cyclosporine A ) is a
selective immunosuppressant inhibits IL2 and T-cell activation. also has
an inhibitory effect on eosinophils activation.
Topical 2% drops - effective as steroid sparing drug in severe VKC and AKC.
effect is usually transient. S/E:
• Intense stinging.• Keratitis.
• Systemic CsA has been used in patients with AKC.
Newer drugs Anti IgE -- Omalizumab Decreases free IgE levels and down-regulates IgE receptors on basophils used for seasonal and perennial allergic conjunctivitis immonotherapy Long term administration of low but progressively increasing doses of the offending allergen until the evoked clinical reaction is reduced or eliminated. sublingually, nasally, bronchially, ocularly, and subcutaneously (usual route ) Recent meta-analysis showed that it is useful for allergic conjunctivitis.