BNF for Children 2011-2012

370 6.3.2 Glucocorticoid therapy BNFC 2011–2012Florinef c (Squibb) ATablets, scored, fludrocortisone acetate 100 micrograms.Net price 100-tab pack = £5.05. Label: 10,steroid cardExtemporaneous formulations available seeExtemporaneous Preparations, p. 6Note Bioavailability uncertain, tablets may result in morereliable absorption and may be dispersed in waterBetamethasone and dexamethasone also have a longduration of action and this, coupled with their lack ofmineralocorticoid action makes them particularly suitablefor conditions which require suppression of corticotropin(corticotrophin) secretion. Some esters of betamethasoneand of beclometasone (beclomethasone)exert a considerably more marked topical effect (e.g.on the skin or the lungs) than when given by mouth; useis made of this to obtain topical effects whilst minimisingsystemic side-effects (e.g. for skin applications andasthma inhalations).Deflazacort has a high glucocorticoid activity; it isderived from prednisolone.6.3.2 Glucocorticoid therapy6 Endocrine systemIn comparing the relative potencies of corticosteroids interms of their anti-inflammatory (glucocorticoid) effectsit should be borne in mind that high glucocorticoidactivity in itself is of no advantage unless it is accompaniedby relatively low mineralocorticoid activity (seeDisadvantages of Corticosteroids below). The mineralocorticoidactivity of fludrocortisone (section 6.3.1) isso high that its anti-inflammatory activity is of noclinical relevance. The table below shows equivalentanti-inflammatory doses.Equivalent anti-inflammatory doses of corticosteroidsThis table takes no account of mineralocorticoid effects,nor does it take account of variations in duration ofactionPrednisolone1 mg: Betamethasone 150 micrograms: Cortisone acetate 5 mg: Deflazacort 1.2 mg: Dexamethasone 150 micrograms: Hydrocortisone 4 mg: Methylprednisolone 800 micrograms: Triamcinolone 800 microgramsThe relatively high mineralocorticoid activity of cortisoneand hydrocortisone, and the resulting fluid retention,make them unsuitable for disease suppression on along-term basis. However, they can be used for adrenalreplacement therapy (section 6.3.1); hydrocortisone ispreferred because cortisone requires conversion in theliver to hydrocortisone. Hydrocortisone is used on ashort-term basis by intravenous injection for the emergencymanagement of some conditions. The relativelymoderate anti-inflammatory potency of hydrocortisonealso makes it a useful topical corticosteroid for themanagement of inflammatory skin conditions becauseside-effects (both topical and systemic) are less marked(section 13.4); cortisone is not active topically.Prednisolone has predominantly glucocorticoid activityand is the corticosteroid most commonly used by mouthfor long-term disease suppression.Betamethasone and dexamethasone have very highglucocorticoid activity in conjunction with insignificantmineralocorticoid activity. This makes them particularlysuitable for high-dose therapy in conditions where fluidretention would be a disadvantage.Use of corticosteroidsDosages of corticosteroids vary widely in different diseasesand in different children. If the use of a corticosteroidcan save or prolong life, as in exfoliativedermatitis, pemphigus, acute leukaemia or acute transplantrejection, high doses may need to be given,because the complications of therapy are likely to beless serious than the effects of the disease itself.When long-term corticosteroid therapy is used in somechronic diseases, the adverse effects of treatment maybecome greater than the disabilities caused by thedisease. To minimise side-effects the maintenancedose should be kept as low as possible.When potentially less harmful measures are ineffectivecorticosteroids are used topically for the treatment ofinflammatory conditions of the skin (section 13.4). Corticosteroidsshould be avoided or used only underspecialist supervision in psoriasis (section 13.5).Corticosteroids are used both topically (by rectum) andsystemically (by mouth or intravenously) in the managementof ulcerative colitis and Crohn’s disease (section1.5 and section 1.7.2).Use can be made of the mineralocorticoid activity offludrocortisone to treat postural hypotension in autonomicneuropathy.High-dose corticosteroids should be avoided for themanagement of septic shock. However, low-dose hydrocortisonecan be used in septic shock (section 2.7.1) thatis resistant to volume expansion and catecholamines,and is accompanied by suspected or proven adrenalinsufficiency.The suppressive action of glucocorticoids on the hypothalamic-pituitary-adrenalaxis is greatest and mostprolonged when they are given at night. In most adultsa single dose of 1 mg of dexamethasone at night issufficient to inhibit corticotropin secretion for 24hours. This is the basis of the ‘overnight dexamethasonesuppression test’ for diagnosing Cushing’s syndrome.Betamethasone and dexamethasone are also appropriatefor conditions where water retention would be adisadvantage.A corticosteroid can be used in the management ofraised intracranial pressure or cerebral oedema thatoccurs as a result of malignancy (see also p. 19); highdoses of betamethasone or dexamethasone are generallyused. However, a corticosteroid should not be usedfor the management of head injury or stroke because itis unlikely to be of benefit and may even be harmful.