Q: I was found to have moderate bone thinning and have been on alendronate 10mg tablets on every morning on an empty stomach and nothing else to eat or drink for one and a half hours afterwards (including tablets) so I now take my Addison’s morning tablets after this time has lapsed. About 11am I start to feel slightly wrong but I take another tablet at midday so at dinner time I feel Ok for the rest of the day, is there anyway of overcoming this? I also take one calcium 500mg per day. (Cannot change alendronate tablets as the other type have citric acid in calcium tablets you take with them in the pack and citric acid gives me migraine).

A: Therapy such as alendronate must be taken on an empty stomach. It would be quite inappropriate however to delay taking the morning dose of hydrocortisone since this could have seriously adverse effects. In this situation I would advise my patients to take their normal morning dose of hydrocortisone, with water but not food. I would then tell them to wait thirty minutes before taking their alendronate and then a further thirty minutes before eating breakfast. They should of course remain upright for at least thirty minutes after the dose. It is not necessary to have nothing to eat or drink for one and a half hours afterwards but only to wait thirty minutes providing the stomach is empty. I am not surprised that the patient feels unwell by midday as her cortisol levels would be very low.

If hydrocortisone is taken after breakfast rather than on an empty stomach then absorption is slow. It would not be right to take one dose of hydrocortisone at 11am and another at midday since the effects of these would coincide giving levels that are too high.

It must be remembered that circulating hydrocortisone levels in subjects who do not have Addison’s disease are normally at their highest about thirty minutes after the usual time of waking. By taking the hydrocortisone with a little water on an empty stomach the normal pattern of hydrocortisone secretion is most closely mimicked. Calcium tablets can be taken at any time of the day.