Friday 9 January 2009

NSAIDS, Corticosteroids & Their Ophthalmic Use

Inflammation of tissues if not too severe can be managed by anti-histamines and NSAIDs. If the inflammation is more severe then corticosteroids are useful.

Corticosteroids can act as anti-inflammatory agents as well as having a number of other effects on the body. Therapeutic corticosteroids work to directly block the production of inflammatory mediators (prostaglandins) while NSAIDs act as inhibitors of the enzymes that produce the prostaglandins.

OCULAR NSAIDs

Uses
  • For seasonal allergic conjuntivitis eg diclofenac sodium 0.1% avail as PoM Voltarol Ophtha Multidose 5ml. For use QDS to reduce redness, discomfort and lacrimation assoc w/SAC. Supplemental anti-histamines will probs be needed to reduce residual itching etc. They shouldn't normally be used for more than a few weeks - then mast cell stabilisers can take over.
  • As a topical analgesic. Again diclofenac sodium 0.1% can be used in the management of pain/discomfort after abrasions of the cornea and conj and also after refractive surgery. This is usually for a short period of time eg QDS for 2 days.
  • Before & after general surgery to the eye eg cataract surgery or the extraocular muscles in strabismus surgery
The use of anti-inflammatory drugs on the eye has been promoted whenever there was evidence of the possible development of inflammatory signs/where clear inflammation was present or the eye had been subjected to trauma where inflammation was an expected sequel to the trauma. By reducing the tissue production of prostaglandins NSAIDs can be very effectively used prophylactically.

Different Preparations
  • DICLOFENAC SODIUM is marketed as PoM Voltarol multidose w/a unit dose for those w/allergy to preservatives (thiomerosal). As a NSAID is can reduce the risk of CM oedema post-cataract ops. It also maintains mydriasis during surgery and has sufficient anti-inflammatory efficacy to be used to manage general ocular inflammation after surgery too for up to 4-6wks. It means narcotic analgesics (corticosteroids) can be used less. There is now a P oral diclofenac that an optom can sell or at least recommend.
  • KETOROLAC TROMETAMOL ophthalmic solution 0.5 (PoM Acular 5ml bottle) is indicated as a prophylactic for inflammation and associated symptoms following cataract surgery. Its use is similar to diclofenac eg TDS for the day prior to surgery and then TDS for up to three wks (ie better than Voltarol)
  • FLURBIPROFEN ophthalmic solution (PoM Ocufen 10x0.4ml SDUs) 0.03%soln in 1.4% PVA. Only indicated for intensive use as a general anti-inflamm drug for cataract ops, esp in case where corticosteroids are contraindicated.
Additional Supply optoms can use topical diclofenac sodium to control pain following eg recurrent corneal erosion w/chronic tear film instability - painful episodes of loss of poorly adherent epithelium.

CORTICOSTEROIDS FOR OPHTHALMIC USE

  • Corticosteroids take a relatively long time to work ie days so way need to be given for several days before any effect is obvious whereas NSAIDs can produce effects in hours. Antihistamines can produce effects between minutes and hours
  • No routine access to optoms but should be on future lists. Px currently has to go to GP or ophthalmologist since nurse prescribers can only access non-ocular steroids.
Indications for use

Primarily for non-infectious inflammatory disorders
  • Assoc w/chronic chemical or drug irritation of the eyelids that leads to oedema of the eyelid margins and palp. conj. eg those w/severe allergic reactions of any type, seasonal allergies, acute or subacute allergic blepharitis from airborne sources or contact w/chemicals or drugs etc
  • Chronic irritation of palp/bulbar conj assoc w/repeated exposure to allergens (eg Vernal Conjunctivitis) or assoc w/mechanical-chemical irritation (eg CLPC)
  • For superficial punctate keratitis of almost any aetiology, generalized diffuse keratitis of a non infectious aetiology, toxic keratitis and when there's non-ulcerating active stromal involvement
  • For acute/subacute/chronic inflammatory conditions of the sclera, anterior uveal, iris and cornea assoc w/mechanical, chemical or bacterial trauma
  • Adjunct use in generalized iritis & anterior uveitis
CLINICAL USE OF CORTICOSTEROIDS

DOSING
  • Should be started at 3-4x a day when the presenting signs are mild to moderate, in very severe cases every two hours for the first 24 only. In many cases you're only going to use them short term anyway and up to 3wks maximum. Should show improvement in 48h and definite improvement in 7 days. In some cases if there isn't a great improvement in primary care might need to be referred to ophthalmologist. In special cases the therapy can continue for many months and we have to start paying attention to the various side/adverse effects
  • Therapy shouldn't be abruptly discontinued. Slowly reducing dose should allow us to see how inflamed the eye actually is and avoid there being an acute rebound response. Reduce to twice a day then once a day after a day or so and monitor. Should allow us to see true status of corneal/conj surfaces including any sign of infection
FOLLOWUP
  • Mild-Moderate -review after a week, more severe every three days til substantial resolution of condition has occurred. Periodic examinations (every 2 weeks) are necessary for longer term treatments to monitor the efficacy of the steroid regimen, to allow appropriate changes in regimen and monitor the adverse effects
  • Assessment should include general inspection inc eyelid eversion, slit lamp w/anterior chamber assessment for cells/flare and evaluation of pupil/iris esp for signs of acute inflammatory reaction. Patient records should include notes as to inflamm magnitude. Allow safety of use of drugs should be reconsidered every time - is an infection (bacterial, viral, fungal, protozoan) present? Are adverse reactions developing?
WARNINGS
  • Generally contraindicated in purulent infections. Can mask and interfere with concurrent bacterial infections in which lots of gunk may obscure other conditions/underlying infections. Any infection should be managed properly using an antibiotic. Get infection under control before starting w/steroids generally. The eye quietening effects of the roids may not show all of the expected early signs and symptoms of an infection
  • Excessive topical ocular roid therapy may retard the natural re-surfacing/healing processes of the surface membranes. Do not overuse - nothing more that q4 or q6 except in initial treatment of v.severe conditions (see above) Can lead to stromal thinning and loss of cornea!
  • IOP may be raised and 'steroid glaucoma' induced. IOP should be periodically assessed. Only really 'common' in a specific bunch of people who are predisposed ('steroid responders'). Time period where IOP rise can be detected = 2 to 3 weeks - this is why steroid use is normally limited to around this time cos any chance of a rise happening within the first two to three weeks is minimal. Check the IOPs beforehand!
CONTRAINDICATIONS
  • Concurrent active HSV infection. Can exacerbate it. Initial slit lamp w/flu should rule HSV out
  • Concurrent fungal/protozoan infections. Again may exacerbate
  • Active tuberculosis infections. Same again
PRODUCTS (more potent as you go down)
  • Hydrocortizone as eyedrops/ointment can be used for relatively superficial non-infectious inflammatory conditions of the eyelids or conjunctiva where there is no major defect or sign of ulceration 1% PoM eyedrops 10ml bottle, 0.5% PoM generic ointment 3g tubes. Used by hospitals and GPs
  • Betamethasone is indicated for use in moderate inflammatory conditions of eyelids, conj, cornea and ant seg assoc w/allergic, chemical or mechanical trauma. 0.1% eyedrops (PoM Betnesol) or 3g tube ointment PoM Betnesol white soft paraffin/liquid paraffin
  • Dexamethasone is generally for moderate inflammations but can be used intensively for severe inflammations including as a post-op steroid. Avail as eye drops 0.1% w/hypromellose 0.5 in 5ml or 10ml bottles and also minims for post-op use. Some combos w/antibac drugs are also available
  • Prenisolone is indicated for moderate or severe inflammations. Prednisolone sodium phosphate ophthalmic solution is available at 0.5% in a 10ml bottle and minims are available for A&E or post-op one off uses. PoM Pred Forte 1.0% is also avail in 5ml and 10ml bottles. No generic products but some in combo w/antibacs
  • Fluorometholone - potent but used in UK at 0.1% for mild-moderate inflammations when a rapid response is deemed appropriate. Avail as eye drops at 0.1% concentration w/PVA in PoM FML Liquifilm 5ml or 10ml bottles
  • Rimexolone and loteprednol are indicated for intensive use either to manage uveitis or for post-op use. They are 'soft' corticosteroids that have substantial anti-inflam effects but are biotransformed so rapidly to what appear to be inactive metabolites that the side effects profile is lessened

No comments: