ACE inhibitor or ARB plus potassium citrate, magnesium glycinate, or beetroot: what potassium labs and timing do you use?
Evidence Desk prompt for people on lisinopril or losartan, with or without HCTZ, who also take supplements. ACE inhibitors and ARBs reduce aldosterone and can raise serum potassium, especially with chronic kidney disease (eGFR under 60) or diabetes. Potassium citrate, potassium-rich beetroot extract, and salt substitutes (KCl) can add to this. HCTZ pulls the other way and can lower potassium. Some questions to compare: Did your prescriber approve any potassium supplement before you started? What was your last potassium, and what is your cutoff (many clinicians act above 5.0-5.5 mEq/L)? How soon after starting or changing an ACE inhibitor or ARB did you get a BMP (typically 1-2 weeks)? Magnesium glycinate is usually less of a concern, but those with CKD should check first. Calcium citrate-malate should be taken 4 hours away from levothyroxine. Please share lab timing, not dosing advice for others.
The FDA DailyMed losartan label warns that hyperkalemia can occur with potassium supplements or potassium-containing salt substitutes, and notes risk with impaired renal function. The NIH Office of Dietary Supplements advises that potassium intake should be individualized in people taking ACE inhibitors or ARBs, with monitoring of serum potassium.