Topiramate can induce hypoadrenalism in patients taking oral corticosteroid replacement

doi:10.1136/bmj.39588.561840.BD

Published 8 January 2009, doi:10.1136/bmj.39588.561840.BD
Cite this as: BMJ 2009;338:a1788

Practice

Drug Point

Topiramate can induce hypoadrenalism in patients taking oral corticosteroid replacement

K Jacob, specialist registrar¹, P J Trainer, professor of endocrinology¹

¹ Department of Endocrinology, Christie Hospital NHS Trust, Manchester M20 4BX

drkoshyjacob@gmail.com

The first 150 words of the full text of this article appear below.

A 35 year old woman was taking life long glucocorticoid (dexamethasone)and mineralocorticoid (fludrocortisone, Florinef, Squibb) replacementfor congenital adrenal hyperplasia caused by 21-hydroxylasedeficiency. She started taking topiramate (Topamax, Janssen-Cilag)in March 2005, and the dose was titrated to 100 mg daily foratypical seizures secondary to mesial temporal sclerosis.

Before starting topiramate she had been taking stable dosesof dexamethasone (0.25 mg a day) and fludrocortisone (100 µga day), with biochemical evidence of good control of her congenitaladrenal hyperplasia (figure). Within a few weeks of startingtopiramate she complained of tiredness, nausea, weight loss,and muscle aches.

A diagnosis of hypoadrenalism was supported by raised plasma17- hydroxyprogesterone, adrenocorticotrophin, and plasma reninactivity. The rises in 17-hydroxyprogesterone and adrenocorticotrophinindicate an inadequate replacement dose of glucocorticoid (dexamethasone),and the rise in plasma renin activity indicates an inadequatereplacement dose of mineralocorticoid (fludrocortisone).