I Have Been Taking Triamterine For Several Years, Recently D/t

I have been taking triamterine for several years, recently d/t palpatations, I went to a cardiologist who Dx via blood test that my potassium was low and prescribed Potassium Chloride 8MEQ TBCR. He explained that the triamterine was depleting the potassium. He next prescribed Valsartan in lieux of triamterene and said I should stop taking the potassium. Extremely confused!