Refractory or Resistant Hypertension

The Oxford English Dictionary defines refractory, as it relates to physiology, as “unresponsive or not fully responsive to … stimuli” and resistant as “that [which] is not overcome by some disease or drug.” ¹ Both terms have been used to describe hypertensive patients who fail to achieve adequate blood pressure control despite drug therapy. Technically, the definition of “drug‐resistant hypertension,” as promulgated in the sixth report of the Joint National Committee on the Detection, Prevention, Evaluation, and Treatment of High Blood Pressure, ² is the failure to reduce blood pressure to <140/90 mm Hg (or to <160/90 mm Hg in the elderly) “…in patients who are adhering to an adequate and appropriate triple‐drug regimen that includes a diuretic, with all three drugs prescribed in near maximal doses.” Contained within that definition are two useful caveats. The first is the importance of including a diuretic as part of the regimen, since diuretic therapy complements and enhances most other classes of antihypertensive agents. ³ The second issue is the use of near‐maximal doses. However, some patients just do not achieve control, even on a diuretic‐based regimen with good doses of other agents co‐prescribed, so what else should one consider?

In a succinct, evidence‐based review of this topic, Jane O'Rorke and Scott Richardson share their approach, which is based on a gratifying combination of common sense and clinical acumen. ⁴ They begin with five basic questions that address measurement of blood pressure (this includes items such as white coat hypertension), antagonizing substances (add to this list the new cyclo‐oxygenase‐2 inhibitors), aggravating conditions like obesity and sleep apnea, problems with medication regimen compliance, and an unbalanced medication regimen (e.g., use of multiple agents from a single antihypertensive drug class, such as adrenergic blockers, and lack of a diuretic). After these items are considered or addressed, if the pressure elevation persists, they recommend that you then begin the search for a secondary cause.

The article is, in my opinion, a worthwhile read and valuable to have around for reference if you manage difficult‐to‐control hypertensives. Perhaps most appealing in the authors' approach is a mixture of good clinical practice and the support of published literature. Literature like this revives my hope that evidence‐based medicine can be effectively married to basic medical discernment and, in the process, improve the delivery of patient care.