Question: How has it been shown that one adrenal gland REALLY makes enough cortisol? My adrenal works, but not enough for periods of stress. What do I do?
Answer: One normal adrenal gland is able to produce sufficient amounts of cortisol, aldosterone and adrenal androgens to fulfill the body’s needs. If one adrenal gland was removed by surgery because it carried a pheochromocytoma (tumor originating from the adrenal medulla and producing too much adrenalin) or a tumor from the cortex that was producing too much aldosterone (aldosteronoma causing high blood pressure), or a tumor not producing any hormones, but removed because its size was suspicious for adrenocortical cancer, the remaining adrenal will produce enough cortisol. With these type of tumors (not those secreting cortisol), there will be no need to take extra amounts of glucocorticoid following surgery. Rarely when an aldosterone secreting tumor is removed, a relative lack of aldosterone from the remaining gland could cause low blood pressure, fatigue and elevation of serum potassium levels and may necessitate taking a synthetic form of aldosterone called fludrocortisone (Florinef™) for a few weeks until natural production of aldosterone is recovered.
If an adrenal tumor (cortisol secreting adenoma or carcinoma) causing Cushing’s syndrome was removed surgically, the excess cortisol will have suppressed (put to rest) the normal production of ACTH from the pituitary gland; as a consequence of this, the remaining adrenal gland is temporarily decreased in size and not able to produce enough cortisol by itself. It usually takes approximately one year for the pituitary and adrenal to fully recover normal function. During that time it is essential to take an average equivalent of 20-30 mg of hydrocortisone in the form of pills by mouth each day to approximate normal cortisol production. This is usually taken in 2-3 fractionated doses of hydrocortisone, for example 10-15 mg as early as possible upon awakening, followed by a second 10 mg dose at mid morning-noon-time and 5 mg at mid afternoon. In cases of illness or severe stress it is necessary to double or rarely triple this amount for a few days. In cases where one is unable to take or absorb the oral medication (for example gastroenteritis with vomiting), it is mandatory to receive a stress dose of medication though intravenous or intramuscular injection in a hospital. A medical bracelet indicating your need for glucocorticoid replacement should be worn in case of an emergency or accident so medical staff know to immediately administer cortisol replacement in stress doses.
Your physician will evaluate how much your remaining adrenal gland has recovered by measuring cortisol and ACTH levels in blood in the early morning, while fasting before the hydrocortisone tablet is taken. These tests are usually done every 2-3 months until cortisol levels in blood are above 12 mcg/dL (or 200 nmole/L). Once cortisol reaches that level, a stimulation test using synthetic ACTH (called cosyntropin) will determine if your adrenal can increase cortisol levels above 18 mcg/dL. Cortisol levels above 18 mcg/dL indicate sufficient recovery of normal function and replacement medication can be discontinued.
In your case it is possible that the pituitary and adrenal glands have recovered enough so that you do not need any more hydrocortisone replacement on a normal day, but that your system cannot double its production during stress episodes. In cases such as this, typically cortisol levels are sufficient fasting in the morning but do not quite reach 18 mcg/dL after an ACTH test. At this stage of recovery, we advise patients to take cortisol supplements for example, 10-20 mg/day of hydrocortisone for mild infections or during periods of stress. It is usually a question of a few more weeks before a full recovery is reached and supplements are no longer necessary even during stress periods.
By Dr. André Lacroix, Spring, 2015