Inclusion Criteria:

• Age ≥18 years
• Uncontrolled TRH, defined as uncontrolled blood pressure (mean 24-hour ambulatory systolic BP ≥125 mm Hg or diastolic BP ≥80 mm Hg) while being adherent to a stable (no changes in ≥14 days prior) antihypertensive regimen of 3 or more drugs, including an adequately dosed diuretic or unable to tolerate a diuretic.
• The participant agrees to have all study procedures performed

Exclusion Criteria:

• Known hypersensitivity or contraindication to minocycline or other tetracyclines
• Recent (≤3 months prior), ongoing, or expected use of oral antibiotics
• Estimated glomerular filtration rate (eGFR) of <45mL/min/1.73m2, using the MDRD equation
• Known secondary hypertension
• History of hypertensive crisis, defined as any in-patient hospitalizations for hypertensive crisis/emergency within the past year
• History of orthostatic hypotension, defined as two or more episode(s) of orthostatic hypotension (reduction of SBP of >20 mm Hg or DBP of >10 mm Hg within 3 minutes of standing) in the past year
• History of myocardial infarction, unstable angina, syncope, or cerebrovascular accident in prior 6 months
• Evidence of alcoholism or drug abuse
• Severe comorbid conditions (i.e., neoplasms or HIV positive or AIDS)
• Current pregnancy or anticipated pregnancy during the study.