Nursing care
Fludrocortisone and other mineralocorticoids: monitoring, hold triggers and teaching
Written and reviewed by Dana Whitfield, RN, MSN · 4 min read · Updated October 2026
Short answer
Fludrocortisone is a mineralocorticoid that makes the kidney hold sodium and water and excrete potassium. It replaces aldosterone in adrenal insufficiency and expands plasma volume in orthostatic hypotension. Nurses watch blood pressure lying and standing, weight, oedema and potassium, report signs of fluid overload or hypokalaemia, and teach patients never to stop it abruptly.
How fludrocortisone works and why it is used
Fludrocortisone acts like aldosterone on the kidney: it increases sodium reabsorption and increases urinary potassium loss, so plasma volume rises. In primary adrenal insufficiency it is given alongside a glucocorticoid such as hydrocortisone, because it replaces only the salt-retaining hormone, not cortisol. On its own it does not protect a patient from adrenal crisis.
The same volume-expanding effect is used off the adrenal pathway for symptomatic orthostatic hypotension, where retained sodium and water raise standing blood pressure. Here it works only if the patient takes in enough salt and fluid. Knowing which indication is on the chart tells you what a good response looks like and which adverse effect matters most.
Adverse effects come straight from the mechanism
Too much mineralocorticoid effect looks like fluid overload: hypertension, rapid weight gain, swelling of the face or legs, and in vulnerable patients heart enlargement or heart failure. Potassium loss can cause hypokalaemia and hypokalaemic alkalosis, which present as muscle weakness, cramps or palpitations and can trigger dysrhythmias.
In orthostatic hypotension, the important trap is supine hypertension: the patient may be dizzy when standing yet markedly hypertensive when lying flat. Some ankle swelling may be tolerated in this group if there is no heart failure, so the prescriber sets the limit. The label also lists glucocorticoid-type warnings, including masked infection, cataracts and glaucoma with prolonged use.
Monitoring and what to report before the next dose
Baseline and ongoing checks include lying and standing blood pressure, daily weight, oedema, lung sounds and periodic serum electrolytes. Report new crackles, breathlessness, rapid weight gain, a falling potassium, a rising supine blood pressure or muscle weakness, and ask before giving the dose when these appear. The prescriber or protocol decides whether to adjust, supplement potassium or stop.
Interactions add to the potassium problem. Loop and thiazide diuretics and amphotericin B increase potassium loss, and hypokalaemia raises the risk of digoxin toxicity, so combined regimens need closer electrolyte checks. The label also notes a reduced response to oral anticoagulants and added gastrointestinal ulcer risk with aspirin and NSAIDs.
Overdose looks like an exaggeration of the same picture: hypertension, oedema, hypokalaemia, excessive weight gain and an enlarging heart. According to the label these usually settle within days once the drug is stopped, which is why early recognition and a held dose matter more than any specific antidote. Trend the numbers across several days rather than judging a single reading in isolation.
Teaching for adrenal insufficiency and orthostatic hypotension
Patients with adrenal insufficiency take fludrocortisone daily for life with their glucocorticoid. Teach them not to stop either drug suddenly, to carry a steroid emergency card or medical identification, and to follow their specialist's sick-day plan for extra medicine during illness, injury or surgery. Vomiting and being unable to keep tablets down warrant urgent help.
Ask patients to weigh themselves, check for ankle or facial swelling and report weakness or cramps. The dietary advice depends on the plan: some are told to limit sodium and eat potassium-rich foods, while people treated for orthostatic hypotension may be told to keep salt intake up. Teach-back should confirm which instruction applies to them.
Worked scenario: dizzy standing, hypertensive lying
A hypothetical older adult started on fludrocortisone for orthostatic hypotension reports fewer dizzy spells. Lying blood pressure tonight is markedly higher than baseline, there are new crackles at both bases and weight is up two kilograms in three days. Options include giving the evening dose, encouraging extra salt, or withholding and reporting.
Withholding and reporting is the best answer, because new crackles and rapid weight gain suggest fluid overload, the adverse effect the mechanism predicts. Extra salt would worsen it, and better standing symptoms do not outweigh a new respiratory finding. Raising the head of the bed and checking potassium fit the picture while the prescriber reviews the plan.
Sources and further reading
DailyMed: Fludrocortisone acetate tablets prescribing information. Use with a glucocorticoid, sodium retention, hypokalaemia, oedema, heart failure, electrolyte monitoring and interactions.
MSD Manual Professional: Orthostatic hypotension. Volume expansion mechanism, need for adequate sodium, supine hypertension, heart failure and hypokalaemia.
MedlinePlus: Fludrocortisone. Patient warning signs, dietary instructions, ID card, infection precautions and not stopping suddenly.
NHS: Addison's disease treatment. Lifelong replacement, extra medicine during illness or surgery, steroid emergency card and emergency injection kit.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our endocrine practice questions are the closest set to what this page covers.
Common questions
Does fludrocortisone replace hydrocortisone in Addison disease?
No. Fludrocortisone replaces the salt-retaining hormone only. Patients with primary adrenal insufficiency also need a glucocorticoid such as hydrocortisone, and stress dosing during illness is planned around that glucocorticoid.
Which electrolyte is most likely to fall on fludrocortisone?
Potassium. The drug increases urinary potassium loss, and diuretics add to the effect. Watch for weakness, cramps and dysrhythmias, and take extra care if the patient also takes digoxin.
Why check blood pressure lying down if the problem is orthostatic hypotension?
Because fludrocortisone can cause supine hypertension. A patient can still feel faint on standing while having a high blood pressure when lying flat, so both readings guide the prescriber.