Corticosteroid replacement therapy: twice or thrice daily?

Although glucocorticoid replacement is conventionally administered twice daily, the pharmacokinetics of hydrocortisone would predict very low levels of plasma cortisol by mid-afternoon. This study compared plasma cortisol day profiles in 7 hypoadrenal patients while on twice daily and thrice daily hydrocortisone replacement. The twice daily regimen was associated with very low levels of cortisol at 16.00 and 18.00 h. This was eliminated by administering the same total dose in a thrice daily regimen. Furthermore, estimates of 'well-being' by visual analogue scale correlated significantly with simultaneous plasma cortisol levels and 5 of the patients expressed a preference for the thrice daily regimen. The findings suggest that thrice daily glucocorticoid replacement therapy should be adopted routinely.