Ocular allergy are a group of external ocular conditions resulting from one or more types of hypersensitivity reactions to allergens. Anti Allergic eye drops are liquid medicine used to treat symptoms of eye allergies.

1. UNIVERSITY OF GONDAR
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college of Medicine and health sciences
Department of Optometry
Topic-anti allergic drugs
by Group 3

2. Objectives
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 After complete presentation of this topic you are expected to
 Define ocular allergy
 Describe anti allergy drugs & their classification
 List and describe different anti allergy drugs
 Explain the mechanism by which Anti allergy drugs work

3. outline
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 Introduction
 Mechanism of action
 Classification
 Decongestant
 Antihistamine
 Mast cell stabilizer
 NSAIDs
 Corticosteroid

4. Introduction
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 Allergy means altered reaction
 A hypersensitivity to a specific substance that causes the body to
react to any contact with that substance
 Ocular allergy are a group of external ocular conditions resulting
from one or more types of hypersensitivity reactions to allergens
 Four types of allergic responses
 Type I- Immediate/anaphylactic reaction
 Type II- Cytotoxic reaction
 Type III- Immune complex reaction
 Type IV- cell mediated immunity

5. Con…
5
 Cross linkage of adjacent Ig E antibodies by antigen activates the mast cell and it
granulates.
 Which cause release of mediators Histamine , protease , prostaglandin ,
leukotriene and cytokines.
 Cause vascular and smooth muscle reaction , late phase reaction and
inflammation.
 Risk factor-Trigger by some thing like pollen , dust and pet tender

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 Symptoms include-burning
-itching
-red eye
-Swallowed eye lid
-Tearing
 Anti Allergic eye drops are liquid medicine used to treat
symptoms of eye allergies.
 Avoiding object that trigger may be the best solution.

7. Mechanism of action
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 Antigen /Allergan Exposed
 activates immune system
 IgE antibodies
 Binds to mast cells & sensitized
 Calcium channel opening
 Degranulation of mast cell

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Release of preformed mediators membrane
phospholipid
 Histamine
 Tryptase Arachidonic
acid
 Cytokines
 Chymase
 heparin cyclooxygenase
Lipooxgenase
-prostacyclin -
leukotriene
-prostaglandin

9. Main classes of anti-allergy drugs
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1. Ocular Decongestants
2. Antihistamines
3. Mast Cell Stabilizers
4. NSAIDS
5. Corticosteroids

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11. 1.Ocular Decongestants
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 Cost effective choice for mild allergies
 Use with cold compresses
 Artificial tears necessary
 Mechanism of action
• This drugs are adrenergic agonist mainly alpha 1 receptor
 Local vasoconstrictor, temporarily reduces redness and
swallowen blood vessel
 Does not treat itching and sneezing

12. CONT….
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Drug available
 Phenylephrine 0.12% and 0.125%
 Naphazoline (0.012%, 0.05%, 0.1%)
 Tetrahydrozoline (0.05%) Imidazole derivatives
 Oxymetazoline (0.025%)

13. Phenylephrine13
 Mechanism of action-selective alpha one agonist that weakens
beta-adenergic activity.
 It causes vasoconstriction of arterioles and also dilate the pupil.
• used to relive eye redness ,dryness , burning and irritation
Dosage -0.25% to 2.5% solution

14.  SIDE EFFECT OF
DECONGESTION Short duration of action
 It may cause burning and stinging sensation
 Chronic use lead to conjunctiva inflammation and
hyperemia
 Corneal opacity
 Papillary dilation
 Dry eye
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15. 2.Anti-histamines- ocular
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 Mechanism of action
 Blocks H1 receptors which control
. Itching
.Capillary dilation
.Increase in capillary permeability
 Thus providing symptomatic relief from histamine activity
• histamine induced capillary dilatation, increase in capillary
permeability & pain.
 Reduces itching caused from already released histamine
from mast cells and basophils
 Almost always combined with ocular decongestant

16. Con…
16 -Activation of H1 histamine receptors stimulate itching, whereas
H2 receptors are involved in vasodilation.
-Topical ocular antihistamines bind to H1 receptors in the
conjunctiva and this reduces itching but does not reduce redness
 Side effect of anti histamine
-topical antihistamines do not have a long duration of action.
- Adverse reactions can include burning and stinging on
instillation, headache, and dry mouth.

17.  Drugs available
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 Pheniramine, antazoline combined with naphazoline
 Levocabastine HCl ophthalmic suspension 0.5% (Livostin)
 Emedastine difumarate 0.05% (Emadine)
 All QID dosing for 2 weeks

18. Emedastine
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 Mechanism of Action
Histamine H1 antagonist, inhibits vascular permeability
 Emedastine is a selective H1 receptor antagonist that also inhibits
histamine release from mast cell
 Emedastine significantly reduces itching and redness within 10
minutes of instillation,with a duration of action of at least 4 hours.
 It is formulated as a 0.05% solution (Emadine),and the
recommended dosage is four times per day.(QID)
 Emedastine is approved for use in patients 3 years of age and older.

19. 3.Chronic Care Drugs: Mast cell stabilizers
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• These are among the newest drugs.
• Not effective in acute disease
• Must be used regularly for better performance
 Mechanism of action
-Mast cell stabilizers work by inhibiting mast cell degranulation
thereby reducing the release of inflammatory substances.
- However, these agents do not eliminate inflammatory mediators that
have released prior to drug instillation.
Mast cell stabilizers inhibit the degeneration of sensitized mast cells
when exposed to specific antigens by inhibiting the release of
mediators from the mast cells. These agents block calcium ions from
entering the mast cell.

20.  Drug available
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 First generation (older)
• Cromolyn Sodium (Sodium cromoglycate) 4% -BD
• Lodoxaminde 0.1%
• Second generation- BD dosing, same efficacy as first
generation
• Pemirolast potassium 0.1% (Alamast)
• Nedocromil sodium 2% (Alocril)

21. Cromolyn Sodium 4.0 %21
 Mechanisms of action
• Traditional view was that it inhibits mast cell degranulation & release
of mediators of allergic disease by preventing calcium influx.
• However the mast cell stabilizers containing Cromolyn may also act
via other mechanisms. These include inhibition of the activation of
other cell types, including neutrophils,monocytes,and eosinophils.
• Cromolyn may also prolong the tear breakup time in patients with
chronic conjunctivitis
• Its main mode of action is to prevent mediator release and its
subsequent clinical manifestations.

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 USE
Effective in treating ocular allergic reactions like vernal
conjunctivitis & keratitis, allergic keratoconjunctivitis & giant
papillary conjunctivitis.
 Side effect
-frequent-stinging
-burning after in installation
-Infrequently- conjunctiva injection,
-watery or itchy eyes,
-dryness around the eye,
- puffy eyes and stys can be seen.

23. 4. Anti-histamines combined with Mast cell
stabilizers23
 Stabilizes mast cell membranes and controls immediate
itching
 Very successful and effective
 Names are: Olopatadine hydrochloride 0.1% (Patanol)
Ketotifen fumarate 0.025% (Zaditor)
Azelastine HCl 0.05% (Optivar)

24. Side Effects
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 Adverse reactions for these multiaction drugs include
burning,
foreign body sensation,
dry eye,
 Systemic side effects may include headache, flu-like
syndrome,and rhinitis.
 Most common to all these drugs is headache, burning and
stinging

25. Olopatadine (Patanol ®)25
 Mechanism of action-
Inhibit release of histamine from mast cells and histamine induced effect
 Indications: treatment of the signs and symptoms of allergic conjunctivitis.
 Dosing: The recommended dose is one drop in each affected eye two times per day at an
interval of 6 to 8 hours.
 Supplied: [0.1% soln,0.2%]
 Side effect –headache
-blurred vision
-dry eye
-foreign body sensation

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

27. Azelastine
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 Mechanism of action- :
• Azelastine hydrochloride is a relatively selective histamine H1 antagonist and
an inhibitor of the release of histamine and other mediators from cells (e.g.
mast cells) involved in the allergic response.
 INDICATIONS AND USAGE:
• Treatment of itching of the eye associated with allergic conjunctivitis.
 CONTRAINDICATIONS:
 Persons with known or suspected hypersensitivity to any of its components
 Dosage- [Supplied: 0.05% ophthalmic solution
- one drop instilled into each affected eye twice a day.
- For patients above 3 years of age.

28. Adverse Effects
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 Transient burning/stinging
 Headache
 Bitter taste

29. Epinastine 0.05%
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 Mechanism of Action
Histamine H1 antagonist, inhibits vascular permeability and release of histamine and other
mediators involved in allergic response; has affinity for H2 alpha1, alpha2
 Dosage BID
 Onset: 3-5 min
 Duration: 8 hr
 Half Life: 12 hr
Total Body Clearance: 56 L/hr
Excretion: Urine 55%; feces 30%

30. 5, NSAID30 • Used regularly in the treatment of allergic reaction
• Used mainly in acute allergic conjunctivitis
• Does not affect IOP, pupillary response or visual acuity.
 Mechanism of action
 NSAIDs inhibit prostaglandin production from arachidonic acid by
blocking cyclooxygenase. which results in vasoconstriction, decrease
in vascular permeability and leukocytosis In turn, this relieves itching
and hyperemia.
 It penetrates the cornea & reaches concentrations that reduces prostaglandin E
levels in the aqueous humor.
 Topical NSAIDs provide good relief of ocular itching and redness.

31. Con….
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Available drugs
• Ketorolac troethamine (Acular)- First NSAID approved for
topical ocular use in seasonal allergic reactions

32. Ketorolac tromethamine
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 Ketorolac tromethamine is a member of the pyrrolopyrrole
group of NSAIDs
 Mechanism of action-
 It inhibit prostaglandin biosynthesis
 Used to relive itching eyes
 Used to prevent and treat eye swelling due to certain type of eye
surgery
 Work by blocking certain natural substance in your body to reduce
pain and swelling
 Dosage -0.5%

33.  Side effect
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-Transient stinging & burning occurs frequently
-Allergic reactions & superficial keratitis rarely occurs.
 Contraindications
- In patients wearing contact lenses.
-Patient who have previously exhibited sensitivity to acetylsalicylic
acid, phenylacetic acid derivatives & other NSAIDs.

34. 6.Corticosteroids
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 Corticosteroid treatment has a role for managing inflammation
 Used for short term intervention in sever disease.
 Mechanism of action
-One of anti inflammatory protein induced by corticosteroid is
(lipocorine) which interact with and inhibit phospholipase A2 .
-There by blocking release of arachidonic acid and its
subsequent conversion to eicosanoids.
-Inhibition of degranulation of mast cells, basophils and neutrophils
-This drugs are lipophilic which can easily cross cell membrane
and gain access to cytoplasm.

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 Control of inflammatory and immunologic diseases of eye.
 Reduction in capillary permeability and cellular exudation.
 Act on both early and late phase of the allergic reaction by suppressing
mast cell proliferation , inhibiting the production of inflammatory mediators
Available drugs
 Has 4 groups
1 ,hydrocortisone-contain prednisone/1%/ and hydrocortisone/0.5%/
2,Acetonide- contain triamcinolone and actinide
3,Betamethasone –dexamethasone/0.1%/
4,Ester betamethasone-methyl prednisolone.

36. Classification
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 Short acting
Hydrocortisone, cortisone, prednisolone
 Intermediate acting
Triamcinolone, Fluprednisolone
 Long acting
Dexamethasone ,betamethasone

37. Dexamethasone
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 Dexamethasone is available as an alcohol or phosphate
derivative in the form of a 0.1% ophthalmic suspension or
solution.
 It is also formulated as dexamethasone sodium phosphate
ointment,0.05%
 Used to treat certain eye condition due to inflammation or
injury.
 Experimental studies indicate that dexamethasone alcohol is
superior in anti-inflammatory activity to dexamethasone sodium
phosphate,

38. Cont...
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 Works by reliving symptoms such as swelling , redness and
itching
 Comes us oral tablet , oral solution , eye drop.
 It’s also available us an injection solution or intraocular solution
 Approximately 4% patient develop high pressure >31 mm hg
after 6 weeks use of this drug.
 Observations suggest that dexamethasone is resistant to
metabolism after penetration into the aqueous humor.
 Peak levels occur between 90 and 120 minutes

39. Side effects
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 Dexametasone may bring
Cataract
Glaucoma
Exophthalmose
 stunning of growth in children
 Impaired myocardial contractility ( prolonged use of it)
 Osteoporosis

40. Fluorometholone 0.1%
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 Unlike prednisolone and dexamethasone, which are structurally
related to cortisol,fluorometholone is a fluorinated structural
analogue of progesterone.
 Formulated both as an alcohol and acetate
derivative,fluorometholone has proven to be an effective agent
in external ocular inflammations,with relatively low potential for
elevating IOP
 After topical application to the eye, fluorometholone alcohol
penetrates and is rapidly metabolized within the aqueous
humor.

41. Cont ...
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 Clinical evaluation of patients with conjunctivitis, episcleritis,
and scleritis indicates that fluorometholone acetate improves
clinical signs and symptoms of inflammation significantly more
than fluorometholone alcohol.
 Furthermore, when fluorometholone acetate 0.1% was
compared with prednisolone acetate 1.0% in patientswith
moderate inflammation, no difference in the antiinflammatory
effects of the two steroids was observed.

42. Prednisolone
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 A synthetic analogue of the major glucocorticoid hydrocortisone
(cortisol), prednisolone has proven an effective anti-
inflammatory agent in patients with external and intraocular
inflammations.
 It is commercially formulated as an acetate and a phosphate.
 Prednisolone acetate is available in 0.125% and 1.0%
concentration
 1% prednisolone acetate is generally considered the most
effective anti-inflammatory agent for anterior segment ocular
inflammation.

43. SIDE EFFECT of corticosteroid
 Ocular -cause cataract
-increasing IOP
-Immune suppression
-Ptosis
-Scleral melting
- midrasis
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46. References
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 www.webmed.com
 www.medscape.com
 Fundemental principle of opthamology
 Pharmacology handout

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