What anti-hypertension medications, such as calcium channel blockers (CCBs), alpha-blockers, or beta-blockers, can be continued when testing for aldosterone and renin?

Antihypertensive Medications Compatible with Aldosterone and Renin Testing

Long-acting calcium channel blockers and alpha-receptor antagonists can be safely continued during aldosterone-renin ratio (ARR) testing as they do not significantly interfere with test results. 1

Medications That Can Be Continued During ARR Testing

• Long-acting calcium channel blockers (both dihydropyridine and non-dihydropyridine types) do not significantly interfere with ARR testing and can be continued 1
• Alpha-receptor antagonists (alpha-blockers) can be safely used without affecting ARR results 1, 2
• Doxazosin specifically has been shown to cause minimal changes in ARR (approximately -5% change from baseline) 2

Medications That Should Be Discontinued When Possible

• Beta-blockers should be discontinued when feasible as they suppress renin secretion and can cause falsely elevated ARR values (approximately +62% change from baseline) 1, 2
• Diuretics should be discontinued as they stimulate renin secretion and can cause falsely negative ARR results 1
• Centrally acting drugs (e.g., clonidine, alpha-methyldopa) should be discontinued as they can suppress renin and potentially cause false positives 1
• Angiotensin receptor blockers (ARBs) like irbesartan can cause false-negative results in up to 23.5% of cases and should be discontinued when possible 2
• ACE inhibitors like fosinopril can decrease ARR by approximately 30% and should ideally be discontinued 2

Two Approaches to ARR Testing in Treated Patients

The 2024 European Society of Cardiology guidelines outline two approaches for ARR testing in patients already on antihypertensive medications:

1. Continue current medications and interpret results in context of the specific medications being taken

   • Advantages: Reduces barriers to screening and maintains blood pressure control
   • Disadvantages: Requires careful interpretation and may need specialist input 1

2. Discontinue interfering medications before testing when feasible

   • Advantages: Provides more reliable and "clean" ARR results
   • Disadvantages: May worsen blood pressure control and increase cardiovascular risk 1

Special Considerations

• If blood pressure control is poor or medications that don't interfere with ARR are insufficient, centrally acting sympatholytic drugs can be used, though they may slightly increase false positives 1
• Mineralocorticoid receptor antagonists (MRAs) like spironolactone typically should be discontinued, but recent evidence suggests they may be continued in cases of severe hypokalemia or severe hypertension with florid primary aldosteronism 1, 3
• MRAs can reduce ARR and lead to false-negative results in up to 48% of patients 3

Practical Algorithm for Medication Management During ARR Testing

1. First-line options (medications with minimal impact on ARR):

   • Long-acting calcium channel blockers (amlodipine causes only -17% change in ARR) 2
   • Alpha-blockers (doxazosin causes only -5% change in ARR) 2

2. If additional medication needed:

   • Consider centrally acting sympatholytic drugs (with awareness of potential false positives) 1

3. Medications to avoid if possible:

   • Beta-blockers, ACE inhibitors, ARBs, diuretics, and MRAs 1, 2

4. If medication cannot be discontinued:

   • Interpret ARR results in the context of medication effects
   • Consider consultation with hypertension specialist or endocrinologist 1

Remember that sodium intake assessment and, for females, menstrual cycle timing are also important for interpreting ARR results 1.