[Adrenal crisis associated with modafinil use]

Adrenal crisis is the most extreme presentation form of adrenal insufficiency and represents a life-threatening endocrinological emergency. This situation can be triggered by different causes including the use of CYP3A4-inducing drugs, which accelerate hydrocortisone clearance. We describe the case of an 85-year-old woman with secondary adrenal insufficiency and chronic renal disease, who presented symptoms compatible with adrenal crisis (asthenia, adynamia, severe hyponatremia associated with neurological symptoms and hypotension) nine days after the start of modafinil treatment. The clinical picture improved rapidly with the suspension of modafinil and the administration of intravenous hydrocortisone. After ruling out the possible triggering causes (infectious, ischemic, pulmonary thromboembolism and failure to take hydrocortisone), it was interpreted that modafinil precipitated the symptoms of adrenal insufficiency by increasing the steroid clearance. Modafinil has the ability to induce the activity of CYP3A4 and consequently decrease the bioavailability of hydrocortisone. We emphasize the need to adjust steroid dose replacement in subjects receiving metabolism-inducing drugs.