Potassium-sparing diuretics (e. g. spironolactone, amiloride, and triamterene), potassium supplements, or potassium-containing salt substitutes and other substances that may increase potassium levels (e. g. heparin) can lead to hyperkalaemia in combination with ACE inhibitors, particularly in patients with renal impairment and other pre-existing conditions (see section 4.4).