anti-allergy and anti-inflammatory drugs in eyecare

• Inflammation

  Part of the body's response to injury, infection, or irritation (allergen)
• Type 1 Hypersensitivity

  • Hypersensitivity – exaggerated response
  • 1st exposure: Initial inflammation reaction to innocuous substance (allergen), Antibodies (immunoglobulins, Ig) are produced to recognise the allergen in the future
  • Repeat exposure: Antibodies recognise the allergen, Inflammation is initiated, mediated by mast cell degranulation
• Itching, Blood vessel dilation, Increased blood vessel permeability


  What Type 1 Hypersensitivity looks like clinically
• Mast cell stabilisers

  • Prevent mast cells from degranulating, Stop further release of inflammatory mediators (including histamine), No effect on histamine already released, Substantial delay (up to 2 weeks) between beginning treatment and therapeutic effect, Useful for management of long-term allergic eye conditions, Most effective when used for prophylaxis
• Mast cell stabilisers with seasonal/perennial allergic conjunctivitis

  • Seasonal: Ocular component of allergic rhinitis (hay fever), Used prophylactically in weeks leading up to Spring
  • Perennial: Non-seasonal allergen, Used year-round or in preparation for periods of allergen exposure
• Sodium Cromoglicate

  Can be GSL, P and PoM, Differences depend on indication of use, bottle size, duration of tx and px age
• Lodoxamide

  PoM, Covers a wide range of subtypes of allergic conjunctivitis
• Antihistamines

  Antagonistic activity at histamine receptor sites, Block histamine from activating its receptors
• Systemic Antihistamines

  • Indicated for both seasonal and perennial allergic conjunctivitis, Particularly recommended if other systemic symptoms (e.g. nasal congestion) are present, Available as Pharmacy (P) medications, Also available as GSL products in smaller quantities
• Sedating Systemic Antihistamines

  Older class of drugs, May induce drowsiness, Cautions: Driving, operating heavy machinery, alcohol consumption, Ocular side effect: Mydriasis (anti-cholinergic effects)
• Non-sedating Systemic Antihistamines

  Newer class of drugs, Less likely to induce drowsiness, Any systemic antihistamine may induce anti-cholinergic systemic side effects: Dry mouth, headache, gastro-intestinal disturbances
• Systemic Antihistamines: Children

  Specific formulations for children younger than 12 years old, Lower concentration of active ingredient, Liquid syrup, rather than tablet
• Topical antihistamines

  • Indicated for both seasonal and perennial allergic conjunctivitis, May be used in combination with mast cell stabiliser, Only available as Prescription only Medications (PoMs), Typically used 2-4 times per day
• Azelastine

  Not for use in children younger than 4 (seasonal) and 12 (perennial) years old, Six-week maximum treatment period
• Emedastine

  Not for use in children younger than 3 years old, Not currently available in the UK
• Olopatadine

  Has some mast cell stabilising properties, in addition to being an antihistamine, Not to be used in children younger than 3 years old, Typical dose twice daily, Four-month maximum treatment duration
• Topical Ocular Decongestants

  • Active ingredient: adrenergic alpha agonists, Mimic action of sympathetic branch of autonomic nervous system, Promote contraction of smooth muscle which lines conjunctival blood vessel walls, Vasoconstrictive action on conjunctival blood vessels, Reduce conjunctival hyperaemia, No effect on underlying cause of hyperaemia, Allergic eye disease better managed with antihistamines or mast cell stabilisers, May make diagnosing ocular disease more difficult by reducing key clinical signs, Indicated to provide temporary relief from mild eye irritation, May be used with other medications to reduce the acute symptoms of seasonal or perennial allergic conjunctivitis, P medicines, Dosing regimen: 2-3 times per day
• Cautions and side effects of Topical Ocular Decongestants

  Ocular side effect: mydriasis (action on pupil dilator muscle), Systemic adrenergic effects mean that these drugs must be used with caution in patients with cardiovascular disorders, arrhythmia, high blood pressure, diabetes, May interact with monoamine oxidase inhibitors (MAOIs)
• Combination Product

  Includes Antazoline- a topical antihistamine, Includes Xylometazoline- a topical decongestant, Indicated for the acute symptoms of seasonal and perennial allergic conjunctivitis, Used 2-3 times per day (7-day maximum treatment period), Not for use in children under 12 years old
• NSAIDs

  Non-Steroidal Anti-Inflammatory Drugs, Inhibit action of the cyclo-oxygenase (COX) enzyme, COX-1: Normal processes in uninflamed tissues, COX-2: Synthesis of prostaglandins in inflamed tissues, Many NSAIDs are non-selective, Inhibition of COX-1 has the potential to cause gastro-intestinal side effects
• Systemic NSAIDs

  • Wide range of indications, Three major properties: Anti-inflammatory (control inflammatory response), Analgesic (relief from pain), Anti-pyretic (control fever), Available as GSL and P medications, Eye care practitioners may recommend that patients use systemic NSAIDs to manage mild to moderate pain (e.g. corneal abrasion)
• Cautions for Systemic NSAIDs

  Not be used by patients with an allergy to aspirin, Avoid in patients with blood clotting disorders, Avoid in patients with gastro-intestinal problems, May exacerbate asthma, Check BNF before offering systemic medications to Px with any GH problems
• Topical Ocular NSAIDs

  • Greater therapeutic effect on ocular region, Reduced risk of systemic side effects, Minimal ocular side effects, Used to control and provide relief from the symptoms of ocular inflammation, Only available as PoMs, Typical dosing regimen: 2-4 times per day
• Corticosteroids

  Steroids are hormones which naturally occur within the body, Steroids regulate innate responses (e.g. inflammation, allergy, immune system), Corticosteroids: both naturally occurring steroids and the synthetic medications which are designed to mimic their action, Mode of action: inhibit release of phospholipase A2 enzyme, Used to control ocular inflammation, Reduces sensation of pain, Reduces risk of ocular tissue damage due to prolonged inflammatory reactions and scarring, All PoMs
• Corticosteroids Dosing

  Initially intensive (e.g. 1 drop every 2 hours for first 48 hours), Reduce to normal therapeutic dose (e.g. QDS), Abrupt cessation may cause rebound effect, 'Taper' dose gradually over a number of weeks
• Contraindications for Corticosteroids

  Infectious keratitis (e.g. a viral infection of the cornea), Corticosteroids suppress the immune system and reduce the body's ability to fight infection
• Adverse Drug Reactions to Steroids

  Rise in IOP => Steroid Glaucoma, Significant rise in IOP in 'steroid responders', Measure IOP at baseline and every 2-4 weeks, IOP typically returns to normal level 1-2 weeks after cessation of treatment, Steroid cataract (posterior sub-capsular cataract), Delayed corneal healing, Peripheral corneal thinning
• 25 year old female returns 1 week later with persisting bacterial conjunctivitis. She also mentions that she has just found out she is pregnant.What is the most appropriate course of action, for you to advise as an ENTRY LEVEL practitioner?

  Give fusidic acid 1% bds for 1 week
• Is chloramphenicol bactericidal?


  no
• Does chloramphenicol work on bacterial cells by disrupting the plasma membrane?

  no
• Does chloramphenicol inhibit the enzyme DNA gyrase?

  no
• Is chloramphenicol useful in the treatment of acanthamoeba keraatitis?

  no
• Does chloramphenicol bind to the 50S sub-unit of the ribosome, suppressing the enzyme peptidyl transferase?

  yes
• A 54 year old man presents with a recurrent flare up of his posterior blepharitis.He is compliant with lid cleaning and compresses bds and hypromellose prn but still feels burning, itchy and gritty eyes. You see this appearance on the slit lamp What should you do next?


  Give fusidic acid 1% bds, apply to eyelid margins, for 2 weeks

  OR

  Give chloramphenicol 1% bds, apply to eyelid margins, for 2 weeks
• A 54 year old man presents with a recurrent flare up of his posterior blepharitis.He is compliant with lid cleaning and compresses bds and hypromellose prn but still feels burning, itchy and gritty eyes. You see this appearance on the slit lamp. How are you going to arrange for the patient to get the ointment?

  provide a written order for PoM chloramphenicol
• Give an example of prophylaxis (fingernail)?

  supplying chloramphenicol drops for a cornea versus fingernail injury
• What is the treatment for herpes simplex keratitis?

  ganciclovir 0.15%
• Why would being pregnant or breastfeeding mean that you can't have ganciclovir 0.15%?

  avoid unless no suitable alternative
• A 39 year old female presents with an acutely painful, photophobic and blurry left eye. She wears monthly lenses and buys them online. She has been wearing the same pair for 3 months.You assess the eye on the slit lamp and see a large stromal infiltrating corneal lesion and hypopyon. She requires an immediate referral to HES for contact lens associated bacterial keratitis.What is the most likely initial treatment she would receive?


  Olfoxacin 0.3% eyedrops every 2 hours
• What happens after the activation of a mast cell, after the binding of the allergen to IgE antibodies?


  itching, blood vessel dilation, increased blood vessel permeability