Switching from Prednisone to Hydrocortisone

Use of overlap in changing from prednisone to hydrocortisone, from 2.5 mg daily prednisone dosage is as follows:

2.5 mg of pred per day = 10 mg of hydrocortisone per day (divided or single dose)

Double the hydrocortisone = 20 mg per day (and divided dose may be best as shorter duration of action for hydro) for the first 7 to 10 days.

Continue with the normal prednisone dosage for the first 5 days.

After the first 7 to 10 days, reduce the hydrocortisone to 10 mg per day.

So:

Day 1 = 2.5 mg pred and 10 mg hydro in a.m., 10 mg hydro in p.m.;
Day 2 = 2.5 mg pred and 10 mg hydro in a.m., 10 mg hydro in p.m.;
Day 3 = 2.5 mg pred and 10 mg hydro in a.m., 10 mg hydro in p.m.;
Day 4 = 2.5 mg pred and 10 mg hydro in a.m, 10 mg hydro in p.m.;
Day 5 = 2.5 mg pred and 10 mg hydro in a.m. and 10 mg hydro in p.m.;
Day 6 = 10 mg hydro in a.m. and 10 mg hydro in p.m.;
Day 7 = 10 mg hydro in a.m. and 10 mg hydro in p.m.,
Day 8 = 10 mg hydro in a.m. and 10 mg hydro in p.m.,
Day 9 = 10 mg hydro in a.m. and 10 mg hydro in p.m.,
Day 10 = 10 mg hydro in a.m. and 10 mg hydro in p.m,
Day 11 = 10 mg hydro in a.m., or a divided a.m. and p.m. dose may be best due to shorter duration of hydro, and continue at that dosage daily.

Hydrocortisone can be compounded into small dosages, such as 1 mg and up, if more precise dosing is preferred (like 2/3 a.m. and 1/3 p.m. dose).

So, the regular pred is continued for the first 5 days, and the equivalent hydro is doubled for the first 7 to 10 days (both are used together 5 days), and after 7 - 10 days the hydro is halved to the normal dosage, and divided dosage may be best due to the shorter duration of hydro.