Anti inflammatory drugs - NSAIDs, Corticosteroids etc Flashcards
anti inflammatory drugs
- corticosteroids
- non steroidal anti inflammatory drugs (NSAIDs)
- ciclosporin
What are corticosteroids
- hormones produced by adrenal cortex
- include glucocorticoids and mineralocorticoids
- levels are regulated by hormones eg adrenocorticotrophic hormone (ACTH) from the pituitary
- glucocorticoids eg cortisol, maintain normal levels of blood glucose and promote recovery from injury
- mineralocorticoids eg aldosterone affect NA+ balance causing NA+ reuptake and water retention and so influence blood pressure - involved in the control of electrolytes
The two main pharmacological actions of glucocorticoids
1) anti inflammatory and immunosuppressive effects through reduction in activity of inflammatory mediators eg eicosanoids, platelet activating factor and interleukins
2) metabolic effects on carbohydrates, protein and fat
systemic therapeutic uses of corticosteroids
- anti inflammatory effects (systemic or topical) eg asthma, eczema, IBD, rheumatic disease
- replacement therapy for disease of adrenal gland - as these pxs would have lower than usual levels of corticosteroids
- chemotherapy eg acute leukaemia, hodgkin lymphoma
- immunosuppression eg post transplantation
adverse effects of corticosteroids
- common and can be severe
- adverse effects are dependent on dose and duration of treatment
adverse effects include:
- impaired glucose tolerance or sometimes diabetes mellitus
- osteoporosis
- cushings syndrome
- immune suppression
opthalmic corticosteroids - give 3 indications
- used for treatment of actute and chronic inflammation eg anterior uveitis, vernal conjunctivitis
- used to reduce post operative inflammation
- intravitreal steroids used to treat macular oedema ( particularly after retinal vein occlusion) and some cases of posterior uveitis
opthalmic cortiocosteroids - which one to use?
There is no official potency hierachy for topical ocular gluococorticoids, the efficacy of a particular glucocorticoid preparation depends not only upon its strength but:
- the salt used, prednisolone acetate can penetrate deeper into ocular tissues and is more lipid soluble so reduces inflammation more effectively than prednisolone sodium phosphate
- the integrity of the cornea, the drug will penetrate eye better if cornea is abraded
it is generally accepted that prednisolone acetate and dexamethosone are used when inflamm is severe and low strength prednisolone sodium phosphate (0.05 or 0.1%) or hydrocortisone are used in mild inflamm or whne glucocorticoid side effects need to be minimal eg in the presence of a viral infection
available preparations of opthalmic corticosteroids
1) betamethsone (betnesol)
2) dexamethosone - maxidex
3) fluorometholone - FML
4) loteprednol etabonate - lotemax
5) prednisolone - predsole, pred forte
combined preparations with antibiotics eg netnesol n, maxitrol, tobradex - eg after surgery
- intravitreal corticosteroids (ozurdex intravitreal implant of dexamethosone for macular oedema following retinal vein occlusion and non infective posterior uveitis)
opthalmic corticosteroids adverse reactions - cataract
- prolonged use of steroids associated with an increased risk of posterior sub capsular cataract
- dose dependent
- accounts for approcx 4% cartaracts
- usually only occurs in px taking high dose steroids for >1yr
opthalmic corticosteroids adverse reactions- IOP
- principal acute adverse reaction to short term use is raised IOP in steroid responsive individuals - can lead to steroid glauc if undetected
- raised IOP can occur with topical, inhaled or systemic steroids
- acute response
- can occur irrespective of how steroid is delivered
- high potency steroids eg dexamethosone are more likely to cause increase in IOP in steroid responsive individuals
NSAIDs
- topical NSAIDs provide mild to moderate anti inflam potency wihtout the side effects of corticosteroids
- NSAIDs prevent the formation of a family of compounds called eicosanoids
biological action of eicosanoids
- important mediators of inflam response
- principal eicosanoids are prostoglandins and the leukotrienes
- ocular effects of eicosanoids include: vasodilation, increased IOP, miosis, macula oedema
- the anti inflammatory action of NSAIDs is primarily due to the inhibition of the enzyme cyclo-oxygenase (COX)
indications of opthalmic NSAIDs
- reduction of intra operative and post operative ocular inflammation
- in some centers have been used in the reduction of post operative pain - due to analgesic effect
- reduction of pain following corneal trauma (diclofenac sodium)
- allergic conj (diclofenac sodium)
- episcleritis (off license)
available topical NSAIDs
1) diclofenac sodium - voltarol (licensed for pain following corneal epi trauma and also for SAC)
2) flurbiprofen - ocufen
3) ketorolac trometamol - acular
4) nepafenac - nevanac
5) bromfenac - yellox
ciclosporin
- has been used extensively as an immunosuppressant following transplantation
- inhibits the release of cytokines from T lymphocytes and therefore suppresses the cell mediated immune response
- licensed for the treatment of severe keratitis in dry eye disease (which has not improved with ocular lubricants) (Ikervis)
- licensed for treatment of severe vernal conjunctivitis (Verkazia)
