Intractable hyperkalemia due to nicorandil induced potassium channel syndrome.

Nicorandil is a commonly used antianginal agent, which has both nitrate‑like and ATP‑sensitive potassium (KATP) channel activator properties. Activation of potassium channels by nicorandil causes expulsion of potassium ions into the extracellular space leading to membrane hyperpolarization, closure of voltage‑gated calcium channels and finally vasodilatation. However, on the other hand, being an activator of KATP channel, it can expel K+ ions out of the cells and can cause hyperkalemia. Here, we report a case of nicorandil induced hyperkalemia unresponsive to medical treatment in a patient with diabetic nephropathy.