A Phase 4 interventional study of Minocycline Hydrochloride and Placebo in Hypertension, Resistant to Conventional Therapy, sponsored by University of Florida. Recruiting at 1 site in United States. Open to participants aged 18 Years to 100 Years. Per ClinicalTrials.gov, last updated 2026-10-13.
Sponsored by University of Florida · Phase 4, Interventional, and Treatment
The goal of this clinical trial is to learn about the mechanisms by which minocycline effect blood pressure in individuals with treatment-resistant hypertension. The main questions it aims to answer are:
Participants will be randomly assigned to treatment with minocycline or placebo, treated daily for 3 months, to evaluate these questions.
One hundred twenty patients with treatment-resistant hypertension will be enrolled. A total of 34 patients (17 from each treatment arm), who are participants in the main study, will also be enrolled in a substudy that includes neuroimaging. The study will last 3 months, and will include 3 visit time points (screening, randomization visit, 3-month follow-up visit).
Participants will be randomly assigned, in a 1:1 allocation, to minocycline 100 mg twice per day, or matching placebo, each provided by the study, and investigators will be blinded to treatment assignment.
At the baseline and 3-month follow-up visit, subjects will undergo:
Subjects enrolled in the neuroimaging substudy will also have PET/MR imaging performed at each visit. Neuroimaging activities will take place at Emory University in Atlanta, GA.
At the final visit (3-month follow-up), participants will also have blood tests to measure study drug concentration, as a measure of adherence to the assigned treatment.
47 studies on the registry are indexed under Hypertension Resistant to Conventional Therapy; 3 are open to participants now.
This study's planned enrollment of 120 is above the median of 57 across 36 interventional studies indexed under Hypertension Resistant to Conventional Therapy.
Browse Hypertension Resistant to Conventional Therapy studies →University of Florida is the lead sponsor of 1,287 studies on the registry; 199 are open to participants now.
Of its 180 completed or terminated interventional studies of FDA-regulated products, 143 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Minocycline hydrochloride 100 mg, administered twice daily for 3 months
Drug: Minocycline Hydrochloride
Placebo administered twice daily for 3 months
Drug: Placebo
Minocycline Hydrochloride 100 mg twice daily
Also known as: Minocycline, Minocin
Placebo
24-h systolic blood pressure
Change in mean 24-hour ambulatory systolic blood pressure
Time frame: 3 months
Gut microbiome
Change in butyrate-producing gene abundance
Time frame: 3 months
Gut inflammation and leakiness
Change in gut-homing inflammatory T-helper cells
Time frame: 3 months
Neuroinflammation
Change in \[18F\]FEPPA radiotracer uptake on PET/MR imaging
Time frame: 3 months
Mucin-degrading gene abundance
Change in mucin-degrading gene abundance
Time frame: 3 months
IgA+ coated plasma cells
Change in IgA+ coated plasma cells
Time frame: 3 months
Gut leakiness markers
Change in gut leakiness markers, including lipocalin-2, intestinal fatty-acid binding protein (I-FABP), zonulin, and lipopolysaccharides (LPS)
Time frame: 3 months
24-h diastolic blood pressure
Change in mean 24-hour diastolic blood pressure
Time frame: 3 months
24-h heart rate
Change in mean 24-hour heart rate
Time frame: 3 months
Adverse Events
Incidence of treatment-related adverse events
Time frame: 3 months
Started Jan 2025 (actual). Primary completion is estimated for Jul 2028, 42 months after the start.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Minocycline
Hypertension Resistant to Conventional Therapy →