Do I Stop Blood Pressure Meds Before Primary Aldosteronism?

No, you do not always have to stop all your blood pressure medications before the initial screening test for primary aldosteronism. Modern guidelines often recommend doing the first blood test—called the aldosterone-to-renin ratio (ARR)—while you remain on your current treatments ^[1][2]. Your doctor can evaluate the results by factoring in exactly how your specific drugs affect the test ^[3]. If this initial test is borderline or difficult to interpret, your doctor may then ask you to temporarily adjust your medications to get a clearer result.

Understanding the Screening Test (ARR)

Primary aldosteronism is a condition where the adrenal glands produce too much aldosterone, a hormone that retains sodium and loses potassium, driving up blood pressure. The ARR test screens for this by measuring the levels of aldosterone and renin (an enzyme that regulates blood pressure) in your blood.

Because blood pressure medications work by altering your body’s fluid balance and blood vessels, they can change the levels of these hormones and make the test harder to interpret:

• False positives: Some medications heavily suppress renin, making your ratio look high even if you do not have the condition. Beta-blockers, for example, can falsely elevate the test result ^[4].
• False negatives: Other medications raise renin or lower aldosterone, making your test result look normal even when you actually have primary aldosteronism. Mineralocorticoid-receptor antagonists (MRAs) and diuretics (water pills) are common culprits ^[5].

It is important to remember that the ARR is not diagnosed in a vacuum; clinicians interpret the ratio alongside your absolute aldosterone level, renin, potassium levels, and your complete medication list.

How Medications Are Managed Before Testing

There is no single “washout” rule for everyone. The exact timeline depends on the medication, your blood pressure risks, and your doctor’s specific protocol:

• Mineralocorticoid-receptor antagonists (MRAs): Medications like spironolactone and eplerenone have the strongest impact on the test. If it is safe for your heart and blood pressure, guidelines often recommend stopping these for at least 4 weeks before testing ^[5][6]. However, if you take them for severe heart failure or dangerously low potassium, your doctor may decide not to stop them and will interpret the test with them in mind.
• Other common blood pressure drugs: Medications such as beta-blockers, ACE inhibitors, ARBs, and diuretics might be paused or switched prior to the blood draw if a true washout is needed ^[7][4]. However, many patients undergo their initial screening while continuing these medications.

Medications That Interfere Less with the Test

If you do need a medication washout, you will not simply be taken off all treatments. Your doctor will prescribe “bridging” medications—alternative drugs that have a minimal effect on the ARR test ^[3]. Common examples include:

• Alpha-blockers (such as doxazosin) ^[8]
• Certain calcium channel blockers (such as sustained-release verapamil) ^[3][9]
• Hydralazine ^[9]

While these interfere less with the test, they are not universally safe substitutes. They can cause side effects like dizziness upon standing, rapid heartbeat, or fluid retention. Your doctor must carefully choose which, if any, are appropriate for you.

Preparing for the Test (Beyond Medications)

Medications are not the only thing that affects the ARR. To ensure the most accurate test possible:

• Check your potassium: Low potassium suppresses aldosterone, which can cause a false-negative result. Your doctor will likely want to check and correct your potassium levels before the blood draw ^[10].
• Don’t restrict salt: Unless your doctor specifically instructs otherwise, maintain a normal, unrestricted salt diet before the test ^[10].
• Follow posture instructions: The test is highly sensitive to posture. You will usually be asked to take the test in the morning after sitting quietly for 5 to 15 minutes ^[10].

The Importance of Medical Supervision

Never stop or change your blood pressure medications on your own. A medication washout is a delicate process that must only be done under close medical supervision.

Adjusting medications in patients who already struggle with severe hypertension carries real risks. One study of patients undergoing medication adjustment for this specific testing found that 36% experienced some form of adverse event, most commonly a dangerous destabilization of their blood pressure ^[11]. This statistic highlights why you need a structured plan, not that every patient will experience a crisis.

To keep you safe, your doctor should provide a structured washout plan with explicit instructions on how to monitor your blood pressure at home, what your targets are, and what “escape” (emergency backup) medications to take if your blood pressure rises too high ^[12]. You should only take escape medications exactly as instructed by your doctor.

Seek immediate emergency medical care if you experience red-flag symptoms of a hypertensive crisis, such as severe chest pain, severe shortness of breath, new weakness or numbness, confusion, severe headache, or vision changes.

What Happens After the ARR?

The ARR is only a screening test, not a final diagnosis. If your test result is positive, borderline, or affected by medications, it does not immediately mean you need surgery. Your doctor will likely order repeat blood tests, confirmatory tests (like a salt-loading test), or specialized imaging to figure out exactly what is causing your high blood pressure and how best to treat it.