Potassium supplementation often is necessary for patients taking which drug?

Spironolactone is a competitive antagonist of aldosterone and therefore, may cause hyperkalemia if administered concomitantly with potassium supplements. Likewise, the potassium-sparing diuretics triamterene and amiloride cause potassium retention. Furosemide promotes renal potassium excretion and often requires concomitant supplemental potassium administration. Ref: Reilly R.F., Jackson E.K. (2011). Chapter 25. Regulation of Renal Function and Vascular Volume. In L.L. Brunton, B.A. Chabner, B.C. Knollmann (Eds),Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.