Hyperkalemia induced by non-selective beta blockers

It's far more common than you might think, although not always clinically significant. From the Medicine for Residents blog:

I recently had a Chronic kidney diesease patient on low dose Ramipril with a stable potassium level for many months, got admitted to the hospital for an hypertensive urgency.Her renal function & K were stable on admission. She was started on a Labetalol infusion overnight.Next day her potassium level was 6.9mEq/L, and she needed two Insulin dextrose treatment( couple of hours apart) to get that back to normal. Her TTKG(transtubular potassium gradient) was 4. This is hyperkalemia due to Labetalol.

Via Nephron Power.