Tertiary adrenal insufficiency is a condition in which the body cannot produce enough cortisol, a hormone essential for life, because the brain’s control center stops sending the right signals to the adrenal glands. The condition most often develops after long-term use of steroid medications for conditions like asthma or arthritis, but once diagnosed, proper treatment can help most people return to normal, active lives.

How Treatment Aims to Replace What the Body Cannot Make

The main goal of treating tertiary adrenal insufficiency is to replace the cortisol that the body can no longer produce naturally. This replacement keeps the body functioning properly, allows patients to respond to stress, and prevents life-threatening complications. Unlike treatments that aim to cure a disease, therapy for tertiary adrenal insufficiency is about substitution, giving the body back what it has lost.^[1]

Treatment must be tailored to each individual because every person has different remaining adrenal function and different rates at which they process medications. The disease stage, age of the patient, and overall health all influence which specific medications are used and how much is needed. Some people need higher doses during periods of illness or physical stress, while their daily maintenance dose might be quite different.^[12]

Medical societies have established standard treatments based on decades of clinical experience, but researchers continue to investigate new therapies that might better mimic the body’s natural hormone rhythms. Clinical trials around the world are testing modified versions of existing medications and entirely new approaches to hormone replacement. Understanding both the established treatments and the experimental options can help patients and their families make informed decisions.^[14]

It is important to understand that tertiary adrenal insufficiency typically requires lifelong treatment. Even after stopping the steroid medications that caused the condition, the adrenal glands may never fully recover their normal function, or recovery may take many years. Some patients do eventually regain adrenal function, but this cannot be predicted reliably, so ongoing medical supervision remains essential.^[1]

Standard Treatment Approaches

Cortisol Replacement Therapy

The cornerstone of treating tertiary adrenal insufficiency is replacing cortisol, the glucocorticoid hormone that helps the body respond to stress, control blood pressure, regulate blood sugar, and manage inflammation. The preferred medication for this purpose is oral hydrocortisone, which is considered the most physiological option available because it closely resembles the cortisol the body would normally make.^[12]

Hydrocortisone is typically given in two to three divided doses throughout the day, with the largest dose taken in the morning. This schedule attempts to copy the natural circadian rhythm of cortisol production, which peaks in the early morning and decreases throughout the day. Most patients take half to two-thirds of their total daily dose when they wake up, with smaller doses in the afternoon or evening. This mimics how healthy adrenal glands work, releasing more cortisol to help the body prepare for the day’s activities.^[12]

The daily dose of hydrocortisone varies considerably from person to person. Adults typically receive between 15 and 25 milligrams per day, but individual needs may be higher or lower. Children require different doses and dosing schedules because they are growing rapidly and their metabolism works differently than adults. Frequent adjustments are often needed in children to support proper growth and well-being.^[13]

Some doctors prescribe prednisolone instead of hydrocortisone. Prednisolone has a longer duration of action, meaning it stays active in the body for more hours, which allows it to be given once daily rather than multiple times per day. However, because it does not match the body’s natural cortisol pattern as closely as hydrocortisone does, many endocrinologists prefer hydrocortisone as the first choice. The equivalent dose of prednisolone is much lower than hydrocortisone, typically around 4 to 6 milligrams daily.^[11][14]

Adjusting Doses During Illness and Stress

People with tertiary adrenal insufficiency must increase their cortisol replacement during periods of physical stress, such as illness, injury, surgery, or severe emotional distress. This is called “stress dosing” or following “sick day rules.” When the body faces stress, healthy adrenal glands automatically produce more cortisol, but in people with adrenal insufficiency, this cannot happen naturally, so medication doses must be increased manually.^[1]

For minor illnesses like a cold or mild infection, patients typically double or triple their usual daily dose of hydrocortisone. For more serious illnesses with vomiting, high fever, or severe infection, even higher doses may be needed, and sometimes emergency injectable hydrocortisone must be used. Patients are usually taught to give themselves or have family members give them emergency injections if they cannot keep oral medication down.^[12]

Surgery requires particularly careful dose adjustments. Before, during, and after surgical procedures, patients may need intravenous hydrocortisone to ensure their body can handle the stress of the operation. The exact dose depends on the type and duration of surgery. Minor procedures might require 50 to 75 milligrams of hydrocortisone on the day of surgery, while major operations might need 100 to 150 milligrams or more.^[9]

Monitoring and Dose Optimization

Unfortunately, there are no simple, reliable blood tests to check whether the cortisol replacement dose is exactly right. This makes managing tertiary adrenal insufficiency more art than science. Doctors rely heavily on how patients feel and on their reported symptoms to adjust and optimize dosing. Some clinicians use cortisol day curves, which involve measuring blood cortisol levels at multiple times throughout the day, to see how well the medication is working and whether adjustments are needed.^[12]

Signs that the dose might be too low include ongoing fatigue, weakness, dizziness when standing up, weight loss, nausea, or salt cravings. Signs that the dose might be too high include difficulty sleeping, increased appetite, weight gain, or feeling jittery and anxious. Patients should work closely with an endocrinologist who specializes in adrenal disorders to find the right dose and make adjustments when necessary.^[12]

Regular follow-up appointments are essential. During these visits, doctors assess symptoms, check blood pressure, review weight changes, and discuss any recent illnesses or stressful events. Blood tests may be ordered to check electrolytes (sodium and potassium levels) and blood sugar, although these are not direct measures of cortisol replacement adequacy. The goal is always to use the lowest dose that keeps the patient feeling well and prevents adrenal crisis.^[9]

Difference from Primary Adrenal Insufficiency Treatment

An important distinction is that most people with tertiary adrenal insufficiency do not need aldosterone replacement. Aldosterone is a different hormone, a mineralocorticoid that helps regulate sodium and potassium balance and blood pressure. In tertiary adrenal insufficiency, the problem originates in the brain’s hypothalamus, which does not make enough corticotropin-releasing hormone (CRH). This leads to insufficient adrenocorticotropic hormone (ACTH) from the pituitary gland, which then leads to low cortisol production by the adrenal glands.^[1][3]

However, aldosterone production is controlled by a separate system called the renin-angiotensin system, which is independent of the hypothalamus and pituitary. Therefore, aldosterone levels typically remain normal in tertiary adrenal insufficiency. Patients do not usually need medications like fludrocortisone, which is used to replace aldosterone in primary adrenal insufficiency. This is one of the key differences between the types of adrenal insufficiency and affects the treatment plan significantly.^[2][4]

Treatment Options Being Studied in Clinical Trials

Modified-Release Hydrocortisone Formulations

One of the main challenges with standard hydrocortisone tablets is that they must be taken multiple times per day and do not perfectly replicate the body’s natural cortisol rhythm. Cortisol levels in healthy people are lowest around midnight and start rising in the early morning hours, peaking shortly after waking. Standard immediate-release hydrocortisone tablets cause a rapid spike in cortisol levels that then drops quickly, creating an unnatural pattern.^[12]

To address this problem, researchers have developed modified-release hydrocortisone preparations that are designed to better mimic the physiological circadian rhythm of cortisol. One such medication is Plenadren, a once-daily dual-release hydrocortisone tablet. It has a rapid-release outer coating that delivers some hydrocortisone immediately and a timed-release inner core that releases the rest gradually throughout the day. Patients take Plenadren in the morning, and it provides cortisol coverage for the entire day with a more natural pattern than standard tablets.^[12]

Plenadren has been approved by the European Medicines Agency and is available in some European countries. Clinical trials have shown that it can provide adequate cortisol replacement with once-daily dosing, potentially improving convenience for patients and creating cortisol levels that more closely match what healthy people experience. However, it is not yet available in all countries, and long-term studies are ongoing to determine whether it offers significant advantages in terms of patient well-being, cardiovascular health, or metabolic outcomes compared to standard hydrocortisone.^[12]

Another experimental formulation is Chronocort, which offers delayed and sustained release of hydrocortisone. Unlike Plenadren, Chronocort is designed to be taken at bedtime. It maintains low cortisol levels during the night and then produces an early morning peak, more accurately mimicking the body’s natural overnight cortisol secretion pattern. The manufacturer, Diurnal, is committed to conducting additional clinical studies to evaluate its safety and effectiveness, including studies in the United States.^[12]

These modified-release formulations are being tested in clinical trials involving patients with all forms of adrenal insufficiency, including tertiary adrenal insufficiency. Researchers are measuring whether these drugs improve quality of life, reduce fatigue, improve metabolic markers like blood sugar and cholesterol, reduce cardiovascular risk factors, and make it easier for patients to manage their condition. The trials are typically Phase II and Phase III studies, meaning they are evaluating both the effectiveness of the drugs and how they compare to standard treatment.^[12]

Continuous Subcutaneous Hydrocortisone Infusion

For some people, oral hydrocortisone does not work well because they metabolize the medication very rapidly. Their bodies break down and eliminate hydrocortisone so quickly that blood cortisol levels drop too low between doses, causing symptoms of insufficient replacement. These patients may benefit from continuous hydrocortisone delivery using a subcutaneous infusion pump, similar to insulin pumps used by people with diabetes.^[12]

The pump is a small device worn on the body that delivers hydrocortisone continuously through a thin tube inserted under the skin. The infusion can be programmed to deliver different amounts at different times of day, creating a very precise cortisol pattern that mimics the natural circadian rhythm. Some pumps can be programmed to deliver a higher rate of infusion in the early morning and lower rates in the afternoon and evening.^[12]

While pumps are not widely used for adrenal insufficiency, they can be an excellent option for patients who are doing poorly on oral steroids. Clinical studies are investigating whether pump therapy improves symptoms, quality of life, and metabolic health compared to standard oral therapy. The technology is still considered experimental in many places, and not all insurance plans cover it. However, for selected patients with severe symptoms despite optimal oral therapy, pump therapy may offer significant benefits.^[12]

Ongoing Research into Optimal Dosing Strategies

Clinical trials are also examining the best dosing strategies for existing medications. For example, researchers are conducting randomized crossover controlled trials comparing different doses and timing schedules of hydrocortisone to determine which approach produces the best outcomes. These studies typically involve giving patients different regimens for several weeks each and measuring various outcomes, including symptoms, quality of life, blood pressure, blood sugar, cholesterol levels, and cortisol levels throughout the day.^[13]

One trial compared doses of 5 milligrams twice daily versus 10 milligrams twice daily of hydrocortisone, measuring outcomes after one week of each regimen. Another trial compared three different daily dosing patterns: 20 milligrams in the morning and 10 milligrams in the afternoon; 10 milligrams in the morning and 10 milligrams in the afternoon; and 10 milligrams in the morning and 5 milligrams in the afternoon. These were six-week trials that measured how each regimen affected patients’ well-being and metabolic markers.^[13]

These trials help establish evidence-based guidelines for glucocorticoid replacement therapy. The National Institute for Health and Care Excellence in the United Kingdom and other medical organizations have reviewed this evidence to create clinical practice guidelines that help doctors choose the most effective and safest treatment approaches. As more research is published, these guidelines continue to evolve.^[13]

Understanding Clinical Trial Phases

When reading about experimental treatments, it helps to understand what different phases of clinical trials mean. Phase I trials are small studies, usually involving 20 to 80 healthy volunteers or patients, designed primarily to test whether a new drug is safe and to determine what dose range should be studied further. Phase II trials involve larger groups, typically 100 to 300 patients, and focus on whether the treatment is effective for its intended purpose and what side effects might occur. Phase III trials are large studies, often involving thousands of patients, that compare the new treatment directly with the current standard treatment to determine which works better.^[12]

Most of the modified-release hydrocortisone formulations have completed Phase II and Phase III trials showing that they are safe and can effectively replace cortisol. However, researchers are still conducting additional studies to better understand their long-term effects and to determine which patients might benefit most from these newer formulations compared to standard therapy.^[12]

Preventing and Managing Adrenal Crisis

One of the most critical aspects of treating tertiary adrenal insufficiency is preventing adrenal crisis, a life-threatening emergency that occurs when cortisol levels become dangerously low. Adrenal crisis can develop rapidly during severe illness, injury, surgery, or other major physical stress if medication doses are not increased appropriately. Symptoms include severe weakness, confusion, very low blood pressure, low blood sugar, severe abdominal pain, vomiting, and loss of consciousness.^[3][10]

Preventing adrenal crisis requires patient education about stress dosing and recognition of warning signs. All patients should carry emergency medical identification, such as a bracelet or card, stating that they have adrenal insufficiency and require hydrocortisone in emergencies. Many patients are prescribed emergency injection kits containing hydrocortisone that they or family members can administer if oral medication cannot be taken due to vomiting.^[1]

If adrenal crisis is suspected, immediate treatment with high doses of intravenous hydrocortisone and intravenous fluids is essential. This is a medical emergency requiring hospital care. Healthcare providers should not wait for laboratory test results before treating suspected adrenal crisis, because delays can be fatal. Treatment typically begins with 100 milligrams or more of hydrocortisone given intravenously, along with fluids and monitoring.^[12]

Studies have shown that adrenal crisis occurs in approximately 6 to 8 episodes per 100 patient-years in people with adrenal insufficiency, and mortality from crisis is about 0.5 per 100 patient-years. The most common triggers are gastrointestinal infections and other infectious diseases. With proper education, emergency preparedness, and prompt treatment, most episodes of adrenal crisis can be prevented or successfully managed.^[9]

Special Considerations for Children

Children with tertiary adrenal insufficiency face unique challenges because they are growing and their hormone needs change frequently. Doses must be adjusted regularly to support normal growth and development. Children also may have difficulty recognizing their symptoms or communicating that they feel unwell, making parental vigilance and education especially important.^[3][10]

Common symptoms in children include fatigue, weakness, and slow recovery from illness. Severe or prolonged illness or infection can result in vomiting, which may quickly progress to adrenal crisis. Children in crisis experience low blood pressure, low blood sugar, lethargy, and possible loss of consciousness. These symptoms require immediate emergency treatment.^[3][10]

School staff and caregivers must be educated about the child’s condition and emergency action plans. Schools should have written protocols detailing when to give extra medication, when to call parents, and when to call emergency services. Emergency hydrocortisone injections should be available at school, and designated staff should be trained to administer them if needed.^[3][10]

Living with Tertiary Adrenal Insufficiency

While tertiary adrenal insufficiency is a serious condition requiring lifelong treatment, most people can live happy, normal, and active lives with proper management. The key is understanding the condition, taking medications consistently, adjusting doses during stress or illness, and maintaining regular follow-up with healthcare providers. Patients should develop a strong partnership with an endocrinologist who has experience managing adrenal insufficiency.^[3]

Education is crucial. Patients and family members should understand what triggers adrenal crisis, how to recognize warning signs, when to increase medication doses, and how to give emergency injections. Many support organizations provide educational materials, online forums where patients can connect with others who have the condition, and resources for medical professionals. The Addison’s Disease Self-Help Group, for example, offers extensive information about tertiary adrenal insufficiency, including patient stories and guidance from clinical advisors.^[1]

Employment considerations are also important. People with tertiary adrenal insufficiency can work in most occupations, but they may need workplace accommodations such as flexibility to attend medical appointments, permission to carry medication and medical supplies, and understanding from supervisors about the need for sick days during illness. Some patients find it helpful to inform their employers about the condition and provide written information about adrenal insufficiency and emergency treatment.^[1]

Recovery of adrenal function after stopping the steroid medications that caused tertiary adrenal insufficiency varies greatly among individuals. Some people gradually regain normal adrenal function and can eventually stop cortisol replacement therapy, but this process can take months to years and requires careful medical monitoring. Other people never fully recover adrenal function and require lifelong replacement therapy. Doctors can perform stimulation tests to check whether adrenal function has returned, but these tests cannot predict who will recover or when recovery might occur.^[1][14]

Most Common Treatment Methods

• Oral Hydrocortisone (Standard Immediate-Release)
  • The preferred and most commonly used medication for cortisol replacement in tertiary adrenal insufficiency
  • Typically given in two to three divided doses daily, with the largest dose in the morning
  • Doses range from 15 to 25 milligrams per day in adults, adjusted based on individual needs
  • Designed to mimic the body’s natural cortisol rhythm as closely as possible
  • Must be increased during illness, injury, surgery, or severe physical or emotional stress
• Oral Prednisolone
  • An alternative glucocorticoid with longer duration of action than hydrocortisone
  • Can be given once daily, typically 4 to 6 milligrams
  • May be used when multiple daily doses of hydrocortisone are not practical
  • Does not match the body’s natural cortisol pattern as closely as hydrocortisone
• Modified-Release Hydrocortisone (Plenadren)
  • Once-daily dual-release hydrocortisone tablet taken in the morning
  • Contains a rapid-release coating and a timed-release inner core
  • Approved by the European Medicines Agency and available in some European countries
  • Designed to better mimic the natural circadian rhythm of cortisol production
  • Still being studied to determine long-term benefits compared to standard hydrocortisone
• Modified-Release Hydrocortisone (Chronocort)
  • Delayed and sustained-release formulation taken at bedtime
  • Maintains low cortisol levels during sleep with an early morning peak
  • Under clinical investigation in multiple countries
  • Not yet widely available but showing promise in clinical trials
• Continuous Subcutaneous Hydrocortisone Infusion (Pump Therapy)
  • Small pump device that delivers hydrocortisone continuously through a tube under the skin
  • Can be programmed to deliver different amounts at different times of day
  • Used for patients who metabolize oral hydrocortisone very rapidly
  • Considered experimental in many places and not widely available
  • May significantly improve symptoms in selected patients who do poorly on oral therapy
• Emergency Injectable Hydrocortisone
  • High-dose hydrocortisone given by injection during adrenal crisis
  • Patients typically carry emergency injection kits for use if oral medication cannot be taken
  • Can be given intramuscularly by patients, family members, or trained caregivers
  • In hospital settings, given intravenously along with fluids for treatment of severe crisis
  • Typical emergency dose is 100 milligrams or more for adults
• Stress Dosing Protocols
  • Guidelines for increasing cortisol replacement during physical stress
  • Minor illness typically requires doubling or tripling the usual daily dose
  • Major surgery may require 100 to 150 milligrams or more of hydrocortisone
  • Each patient receives individualized sick-day rules based on their baseline dose and medical condition
  • Essential for preventing adrenal crisis during times of increased cortisol need