Fludrocortisone – What It Does, How to Take It, and What to Watch For

If your doctor mentioned fludrocortisone, you probably have questions. This tiny pill is a synthetic mineralocorticoid that helps your body keep the right amount of salt and water. In short, it raises blood pressure and balances electrolytes when your adrenal glands aren't doing their job.

Fludrocortisone is most often used for Addison’s disease, primary adrenal insufficiency, and for patients who need extra support after a unilateral adrenalectomy. It can also help people with orthostatic hypotension—when you feel dizzy standing up because blood pools in your legs.

Why Doctors Prescribe Fludrocortisone

The drug mimics the natural hormone aldosterone. Aldosterone tells the kidneys to re‑absorb sodium and excrete potassium. When you’re low on aldosterone, you lose too much sodium, which pulls water out of your bloodstream and drops your blood pressure.

By giving fludrocortisone, doctors give your kidneys a cue to hold on to sodium. The extra sodium keeps water in the bloodstream, which boosts volume and steadies your blood pressure. That’s why patients with adrenal insufficiency often feel better after starting the medication.

Typical Dosage and How to Take It

Most adults start with 0.05 mg to 0.2 mg once a day, usually in the morning. Your doctor may adjust the dose based on blood pressure, electrolytes, and how you feel. The tablet should be swallowed whole with a glass of water; don’t crush or chew it.

It’s important to take fludrocortisone at the same time each day. Consistency helps keep your hormone levels steady and makes it easier to spot any side effects early.

Common Side Effects to Expect

Because fludrocortisone forces your body to retain sodium, you might notice swelling in your ankles or face. Some people get a higher appetite, weight gain, or a mild headache. Less often, the drug can cause high blood pressure, low potassium, or stomach upset.

If you experience severe swelling, rapid weight gain, or a pounding headache, call your doctor right away. These could be signs that the dose is too high.

Drug Interactions and Foods to Watch

Fludrocortisone can interact with certain blood pressure meds, especially ACE inhibitors, ARBs, and diuretics. Those drugs also affect sodium and potassium, so the combination may need a dose tweak.

Non‑steroidal anti‑inflammatory drugs (NSAIDs) like ibuprofen can raise blood pressure further, so use them cautiously. Alcohol doesn’t directly interact, but drinking a lot can worsen dehydration and affect blood pressure control.

Tips for Safe Use

Keep a short log of your blood pressure and any swelling you notice. Bring the log to each appointment; it helps the doctor fine‑tune your dose.

Get your electrolytes checked regularly—especially potassium and sodium. If a lab shows low potassium, your doctor might add a supplement or adjust your diuretic.

Stay hydrated, but don’t over‑drink. Too much fluid can increase swelling, while too little can undo the drug’s purpose.

Always have a valid prescription handy when you travel. Some countries treat fludrocortisone as a controlled substance, so you’ll need proper documentation.

Finally, if you miss a dose, take it as soon as you remember—unless it’s close to the next dose. In that case, skip the missed one and continue with your regular schedule. Doubling up can raise blood pressure too fast.

Fludrocortisone is a powerful tool for people who can’t produce enough aldosterone on their own. By understanding how it works, watching for side effects, and staying in touch with your healthcare team, you can keep your blood pressure stable and feel more like yourself again.