A practical approach to evaluating apparent resistant hypertension

ACE: angiotensin-converting enzyme; ARB: angiotensin receptor blocker; BP: blood pressure; DBP: diastolic blood pressure; GFR: glomerular filtration rate; SBP: systolic blood pressure.

* There are multiple ways of assessing adherence to antihypertensive therapy. The following are more accurate methods but may not be feasible:

• Direct measurement of antihypertensive medications in urine or blood (eg, with mass spectrometry)
• Directly observed therapy (administer the patient's medications in clinic, measuring pressure before and then several hours later to determine if BP is controlled)

The following methods are more feasible but less reliable:

• Ask about adherence (eg, "Do you miss any doses of your antihypertensive medication?")
• Questionnaire (eg, Morisky Medication Adherence Scale [MMAS-4])
• Ask the patient to bring their medication bottles to clinic and calculate the medication possession ratio (MPR; which is the number of medication days available on the prescription compared with the number of medication days filled by the pharmacy)

Refer to UpToDate content on adherence to antihypertensive therapy for more details.

¶ Loop diuretics are typically used instead of thiazide diuretics in patients whose estimated GFR is <30 mL/min/1.73 m².