**4.1 Medical treatment**

Medical management with a mineralocorticoid receptor (MR) antagonist is recommended for patients who do not undergo surgery. Medical treatment is recommended for patients with bilateral hypersecreting adrenal lesions or for those with unilateral lesion who are not optimal for or who do not want surgical treatment (see Pharmacotherapy for hyperaldosteronism). Medications that block aldosterone action are effective for the treatment of hypokalemia and HTN and these include nonselective (spironolactone) and selective aldosterone receptor antagonists (eplerenone). Amiloride is not an aldosterone receptor antagonist and is not effective in controlling HTN in PAL but may be used for its potassium sparing property.

Prior studies on the efficacy of spironolactone in treating resistant HTN have used 25 to 50 mg daily dosing, whereas true PAL may require larger daily doses up to 100 to 400 mg. The onset of action on BP may be slow. Measurements of PRA are not necessary but may be an indication that an optimal dose of the medication has been prescribed when it is no longer suppressed.

Spironolactone is a nonselective MR antagonist with significant antiandrogenic and progestational activities responsible for its most common side effects (gynecomastia, erectile dysfunction and abnormal menstrual cycles) 2. Eplerenone is a selective MR antagonist without antiandrogen or progesterone agonist activity: it has 60% of the potency of spironolactone in vivo and should be administered twice daily given its short half-life. Combined therapy with a small dose of spironolactone and amiloride may alleviate these undesirable consequences.29 Eplerenone, a more selective mineralocorticoid receptor blocker, also effectively reduces BP in patients with resistant hypertension Eplerenone has a beter adverse reaction profile because it has substantially less binding affinity to androgen and progesterone receptors than spironolactone.
