September, 29 2025
Addison’s Disease Dosage Calculator
Enter your details to calculate recommended daily hormone replacement doses for Addison’s disease.
TL;DR
- Addison’s disease needs lifelong hormone replacement to mimic missing cortisol and aldosterone.
- Hydrocortisone (or equivalent) is the go‑to glucocorticoid; fludrocortisone covers mineralocorticoid loss.
- Stress dosing - extra pills during illness or surgery - prevents life‑threatening crises.
- Regular labs and symptom checks keep doses in the sweet spot.
- Work with an endocrine specialist and have an emergency injection kit handy.
Understanding Addison’s Disease
When the adrenal glands stop making enough Addison’s disease is a chronic condition where the adrenal cortex fails to produce sufficient cortisol and often aldosterone, the body loses its natural stress‑response system. People describe feeling constantly tired, dizzy when standing, salty cravings, and darkening of the skin. The culprit? A lack of two key hormones:
- Cortisol a glucocorticoid that regulates blood sugar, blood pressure, and inflammation
- Aldosterone a mineralocorticoid that helps retain sodium and excrete potassium, keeping fluid balance stable
Without these hormones, stress-whether a fever, a marathon, or a simple dental cleaning-can trigger an adrenal crisis, a medical emergency that demands immediate treatment.
What Is Hormone Replacement Therapy (HRT) in This Context?
Hormone replacement therapy isn’t just for menopausal symptoms; in Addison’s disease it’s the lifeline that mimics the missing adrenal output. In plain language, HRT means you take pills (or occasionally injections) that act like the hormones your body can’t make.
Two main parts make up the regimen:
- Glucocorticoid replacement - typically hydrocortisone, but sometimes prednisolone or dexamethasone.
- Mineralocorticoid replacement - almost always fludrocortisone.
Both are prescribed by an endocrine specialist a doctor who focuses on hormone disorders who tailors the dose to your weight, activity level, and lab results.
Glucocorticoid Replacement: The Cortisol Substitute
The goal is to provide a pattern that mirrors the body’s natural cortisol rhythm: a higher dose in the morning, a smaller boost around midday, and little to none at night. Hydrocortisone is the most physiologic choice because its half‑life closely matches natural cortisol.
Typical adult dosing looks like 15‑25mg split into two or three doses (e.g., 10mg upon waking, 5mg at lunch, optional 2-5mg late afternoon). For kids, the dose is weight‑based (about 6‑8mg/m²/day).
Why not just take a big pill once a day? The body’s receptors get overwhelmed, leading to side effects such as weight gain, insomnia, and higher blood pressure-exactly the problems cortisol would normally prevent.
Mineralocorticoid Replacement: Adding Aldosterone Back In
Fludrocortisone (Aldactone a synthetic mineralocorticoid used to replace aldosterone loss) is the workhorse for most patients. The standard dose starts at 0.05-0.1mg daily, adjusted based on blood pressure, sodium, and potassium levels.
If you’re already on a high‑salt diet or have hypertension, your doctor may lower the fludrocortisone dose. Conversely, if you’re prone to low blood pressure or salt cravings, a slightly higher dose can bring relief.
Choosing the Right Glucocorticoid: A Quick Comparison
| Drug | Half‑life | Typical Daily Dose (Adult) | Pros | Cons |
|---|---|---|---|---|
| Hydrocortisone | 8-12hrs | 15-25mg split 2-3× | Most physiologic, easy to titrate | Multiple daily doses |
| Prednisolone | 12-36hrs | 3-5mg once daily | Convenient once‑daily | Longer action may cause over‑replacement |
| Dexamethasone | 36-54hrs | 0.5-1mg once daily | Very potent, useful in special cases | High risk of bone loss, suppresses HPA axis |
Most guidelines (e.g., Endocrine Society 2023) still favor hydrocortisone for its close mimicry of natural cortisol. Prednisolone or dexamethasone may be reserved for patients who struggle with adherence to multiple daily pills.
Stress Dosing: Why One Size Doesn’t Fit All
Imagine catching a cold. Your body’s demand for cortisol spikes, but your replacement dose stays static. That mismatch can tip you into a crisis. The rule of thumb: double or triple your usual hydrocortisone dose for fever >38°C, major surgery, or a serious injury.
Practical steps:
- Keep an emergency injection kit (hydrocortisoneSodiumSuccinate 100mg) prescribed by your doctor.
- Teach family members how to give an intramuscular shot.
- Carry oral stress‑dose tablets (e.g., 10mg hydrocortisone) in a wallet or bag.
- If you can’t keep oral meds down-vomiting, severe diarrhea-use the injection and call emergency services.
Don’t wait for symptoms to worsen; act early. It's better to have a brief “over‑dose” feeling than a life‑threatening crash.
Monitoring & Adjusting Your Therapy
Regular follow‑ups (every 6-12months) let your endocrine specialist fine‑tune the regimen. Key monitoring points:
- Blood pressure - sitting vs standing; a drop >20mmHg suggests under‑replacement.
- Electrolytes - sodium low or potassium high points to fludrocortisone adjustment.
- Weight & BMI - sudden gain may hint at glucocorticoid excess.
- Bone density - long‑term glucocorticoid use can affect bones; DEXA scans every 2-3years are common.
- Quality of life questionnaires - fatigue, mood swings, and sleep patterns are valuable clues.
When labs are normal but you still feel “off,” your doctor may tweak timing or split the morning dose into two smaller pills to smooth out peaks.
Common Pitfalls & How to Avoid Them
- Skipping doses - Even a missed morning pill can cause low cortisol by noon. Set alarms or use a pill‑box.
- Ignoring stress dosing - Treat every fever like a mini‑surgery. Double the dose on day‑one, then taper.
- Relying on over‑the‑counter meds - NSAIDs can irritate the stomach and mask pain, but they don’t replace cortisol.
- Travel without planning - Carry extra medication, keep it in hand luggage, and know where the nearest hospital is.
- Self‑adjusting doses - Always discuss changes with your endocrine specialist; abrupt cuts can trigger a crisis.
Putting It All Together: A Day in the Life
Here’s a realistic snapshot of how a well‑managed patient might schedule their meds:
- 07:00 - Wake up, take 10mg hydrocortisone + 0.05mg fludrocortisone.
- 12:30 - Lunch, take 5mg hydrocortisone.
- 17:00 - Light snack, optional 2mg hydrocortisone if afternoon is busy.
- Any fever or injury - double the next hydrocortisone dose, keep extra tablets in the bag.
- Emergency kit - 100mg IM hydrocortisone ready, instructed family member knows how to inject.
Notice the rhythm mirrors the body’s natural cortisol surge: high in the morning, tapering off by evening.
Frequently Asked Questions
Can I ever stop hormone replacement therapy?
No. Addison’s disease is a permanent loss of adrenal function. Stopping HRT would lead to cortisol deficiency and a high risk of adrenal crisis.
Is hydrocortisone the only glucocorticoid I can use?
Hydrocortisone is preferred because its pharmacokinetics match natural cortisol. Prednisolone or dexamethasone are alternatives for people who struggle with multiple daily doses, but they carry a higher risk of over‑replacement side effects.
How much fludrocortisone should I take?
Typical adult dosing starts at 0.05-0.1mg daily. Your doctor will adjust based on blood pressure, sodium, and potassium labs. Too much can cause hypertension; too little leads to salt cravings and low blood pressure.
What should I do if I miss a dose?
Take the missed dose as soon as you remember, unless it’s almost time for the next dose. If you’re unsure, contact your endocrine clinic for guidance. Never double‑dose without medical advice.
Why is stress dosing so important?
During illness or injury the body normally spikes cortisol to manage inflammation and maintain blood pressure. Your replacement pills stay fixed, so you must artificially boost the dose to cover the extra demand and avoid a crisis.
Can I travel abroad with my medication?
Yes, but plan ahead. Carry a doctor’s note, keep meds in hand luggage, and know the location of hospitals near your destination. A travel‑size emergency kit is a smart backup.
Brandon Phipps
September 29, 2025 AT 19:02Reading through this post reminded me why hormone replacement is such a lifeline for anyone with Addison’s disease. The detailed breakdown of hydrocortisone dosing really hits the mark, especially the emphasis on splitting the dose to mimic the natural circadian rhythm. I also appreciate the clear explanation of why fludrocortisone dose adjustments depend on blood pressure and electrolytes. It’s easy to overlook how a tiny tweak in sodium balance can change a patient’s whole day. The stress‑dosing section is spot‑on; many folks don’t realize that a simple fever can double their cortisol needs. Having an emergency injection kit on hand is not just good practice, it’s a matter of survival during an adrenal crisis. I have seen patients who forgot their kit suffer severe hypotension that could have been avoided. The calculator tool is a neat interactive addition, though I’d love to see it incorporate weight‑based adjustments for kids as well. Regular follow‑ups every six months, as you pointed out, give clinicians the chance to fine‑tune both glucocorticoid and mineralocorticoid dosages. Bone density monitoring is another critical piece, given the long‑term effects of glucocorticoids on skeletal health. I also like how you highlighted the importance of not using NSAIDs as a substitute for proper cortisol replacement. The table comparing hydrocortisone, prednisolone, and dexamethasone is helpful for patients who struggle with adherence. Knowing the pros and cons of each lets them have an informed conversation with their endocrinologist. Overall, the post balances scientific detail with practical advice, making it a valuable resource for both newly diagnosed patients and seasoned veterans of the disease.