On this podcast episode, I discuss some of the most common antihypertensive drug interactions you need to know. One major interaction I discuss is the trifecta of a diuretic, an ACE or ARB, and an NSAID. This combination significantly increases the risk for acute renal failure. Nitrates aren't classically referred to as an antihypertensive but they can definitely cause some problems when combined with PDE5 Inhibitors. Lithium can interact with 3 blood pressure medication classes. ACEIs, ARBs, and diuretics can all increase the risk for lithium toxicity.