Amiloride can cause hyperkalemia due to its action on :

Amiloride and triamterene are K+ sparing diuretics that act by inhibiting epithelial Na+ channels. In the distal tubules and collecting ducts, three separate channels are present (one for Na+, K+ and H+ each). Aldosterone acts on DCT and CD to cause reabsorption of Na+. This generates a lumen negative potential difference across the membrane of this part of the nephron. To maintain the electric neutrality, K+ and H+ are secreted in the lumen.