Suspecting HPA suppression
Small studies in healthy volunteers found that short (5-7 days) courses
of high dose (40-50mg) prednisolone did not produce sustained HPA
suppression [18, 28]. However, adrenal suppression was observed in
steroid-naïve COPD patients after taking prednisolone 40 mg daily for 14
days. This persisted in some patients for at least 21 days [29].
Treatment cessation guidelines in the British National Formulary reflect
this, identifying patients who have received more than 40 mg
prednisolone (or equivalent) daily for more than week or who have
received glucocorticoid treatment for more than 3 weeks as requiring
gradual treatment withdrawal [30].
Other patients who are likely to have HPA suppression secondary to
glucocorticoid therapy include those who have been given repeat doses in
the evening, have recently received repeat courses (particularly if
longer than 3 weeks) and those who take a new short course of
glucocorticoids within 1 year of stopping therapy [30].
The rate of treatment withdrawal in all patients is determined both by
disease control and by suspicion of adrenal suppression. The rate of
reduction from the initial treatment dose down to physiological doses
(equivalent to prednisolone 7.5 mg) is determined by the treatment
requirements of the underlying disease (e.g. table 2). The rate of
reduction from physiological doses to zero is determined by the rate of
HPA recovery and the need for exogenous glucocorticoid cover while
endogenous glucocorticoid secretion recovers. After relatively short
courses of glucocorticoids, HPA suppression can recover in days to
weeks. However, where treatment duration has been long enough for
adrenal atrophy to occur, recovery may take months to years or may not
occur at all, necessitating long term adrenal replacement.