78 Participants Needed

Clonidine + Hydrochlorothiazide for High Blood Pressure

(SELECT Trial)

Recruiting at 1 trial location
AS
GL
Overseen ByGary L Pierce, PhD

Trial Summary

Will I have to stop taking my current medications?

If you are on antihypertensive medications, you will need to stop taking them for a one-week period before the second visit. Other medications like aspirin, NSAIDs, vitamins, and certain supplements must be stopped at least one week before and during the study.

What data supports the effectiveness of the drug Clonidine for high blood pressure?

Clonidine is effective in reducing blood pressure, especially when used with a diuretic, and is well-tolerated by most patients. It has been shown to significantly lower blood pressure in patients with mild to moderate hypertension, and its effectiveness is enhanced when combined with a diuretic.12345

Is the combination of Clonidine and Hydrochlorothiazide safe for treating high blood pressure?

Clonidine, often used with a diuretic like Hydrochlorothiazide, is generally well-tolerated with serious side effects being uncommon. Common side effects include sedation and dry mouth, which can be managed by adjusting the dose. The combination has been shown to effectively lower blood pressure with a good safety profile.15678

What makes the drug combination of Clonidine and Hydrochlorothiazide unique for treating high blood pressure?

The combination of Clonidine and Hydrochlorothiazide is unique because Clonidine, an alpha-adrenergic receptor agonist, reduces blood pressure by decreasing sympathetic nerve signals, while Hydrochlorothiazide is a diuretic that helps remove excess fluid from the body. This dual action can enhance the antihypertensive effect, making it effective for patients who may not respond well to single-drug treatments.578910

What is the purpose of this trial?

Stiffening of your blood vessels, particularly the large vessels from your heart (called the aorta and carotids) you age contributes to the development of cardiovascular disease (CVD) such as heart attack and stroke. Nerve activity from your brain to your body also increases with advancing age but it is unknown if this nerve activity contributes directly to the stiffening on your blood vessels in older adults in addition to high blood pressure. Therefore, successful completion of the proposed aims will have a significant clinical impact by identifying if nerve activity from your brain could be a novel target for therapies that would lower stiffness of the aorta and carotid arteries in older adults.

Research Team

GP

Gary Pierce, PhD

Principal Investigator

University of Iowa

Eligibility Criteria

This trial is for non-smoking adults aged 60-85 with untreated or treated stage 1 or 2 isolated systolic hypertension. Participants must be clinically healthy and not on certain medications like aspirin, NSAIDs, vitamins, or supplements. Women should be postmenopausal without hormone therapy. Those with a history of serious health conditions such as heart disease, diabetes, cancer are excluded.

Inclusion Criteria

I can stop my blood pressure medication for a week and have a systolic BP under 160 mmHg.
I am between 60 and 85 years old.
Non-smoking
See 2 more

Exclusion Criteria

I am a woman who has been postmenopausal for at least 6 months and am not on hormone replacement therapy.
My blood pressure is not between 130/90 and 160/90 mmHg without medication.
I can stop taking aspirin, NSAIDs, vitamins, herbal supplements, and omega-3 for a week before and during the study.
See 2 more

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either Clonidine, Hydrochlorothiazide, or a placebo for 4 weeks

4 weeks
Baseline and after 4 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

  • Clonidine
  • Hydrochlorothiazide
  • Placebo
Trial Overview The study tests if reducing nerve activity from the brain can decrease stiffness in large arteries to prevent cardiovascular diseases. It compares the effects of Clonidine (a blood pressure medication) and Hydrochlorothiazide (a diuretic) against a placebo in older adults with high systolic blood pressure.
Participant Groups
3Treatment groups
Experimental Treatment
Active Control
Placebo Group
Group I: ClonidineExperimental Treatment1 Intervention
0.2 mg/day oral
Group II: HydrochlorothiazideActive Control1 Intervention
37.5 mg/day oral
Group III: PlaceboPlacebo Group1 Intervention
Placebo

Clonidine is already approved in United States, European Union for the following indications:

🇺🇸
Approved in United States as Catapres for:
  • Hypertension
  • ADHD
  • Severe cancer pain
  • Withdrawal symptoms from various substances
  • Diagnosis of pheochromocytoma
  • Prevention of migraines
🇪🇺
Approved in European Union as Catapres for:
  • Hypertension
  • ADHD
  • Severe cancer pain
  • Withdrawal symptoms from various substances
  • Diagnosis of pheochromocytoma
  • Prevention of migraines

Find a Clinic Near You

Who Is Running the Clinical Trial?

University of Iowa

Lead Sponsor

Trials
486
Recruited
934,000+

Findings from Research

A compounded oral clonidine hydrochloride powder (0.2 mg/g) maintained its stability and quality for 120 days under controlled storage conditions, ensuring consistent dosing for pediatric patients.
No degradation products were detected, and the clonidine content remained within the acceptable range (90.0% to 110.0% of initial content), indicating that the compounded formulation is safe and effective for use.
Stability of clonidine hydrochloride in an oral powder form compounded for pediatric patients in Japan.Saito, J., Hanawa, T., Matsumoto, T., et al.[2021]
Clonidine (Catapres-TTS) was effective in significantly reducing blood pressure in 11 out of 25 patients with mild to moderate hypertension during the first four weeks of treatment, but did not show significant effects in patients with more severe hypertension.
While some patients experienced localized contact dermatitis leading to discontinuation of the patch, other side effects like drowsiness and dry mouth were less common compared to oral clonidine, making Catapres-TTS a potentially better option for those who have trouble with the oral form.
Patient acceptance of transdermal clonidine. A retrospective review of 25 patients.Chen, SW., Vidt, DG.[2019]
In a study of 62 mild hypertensive patients, transdermal clonidine was effective in reducing blood pressure, achieving satisfactory control in 85% of participants after 3 months of treatment.
The efficacy of transdermal clonidine was comparable to that of previous treatments (diuretics and beta-blockers), with minimal systemic side effects, although some patients experienced local allergic reactions.
Transdermal clonidine (Catapres-TTS) monotherapy in the management of mild hypertension in general practice.Lewis, GR.[2014]

References

Stability of clonidine hydrochloride in an oral powder form compounded for pediatric patients in Japan. [2021]
Patient acceptance of transdermal clonidine. A retrospective review of 25 patients. [2019]
Transdermal clonidine (Catapres-TTS) monotherapy in the management of mild hypertension in general practice. [2014]
Evaluation of clonidine hydrochloride (Catapres). A new antihypertensive agent. [2016]
Clonidine hydrochloride. [2019]
Comparative efficacy and safety of lofexidine and clonidine in mild to moderately severe systemic hypertension. [2019]
[Therapy of hypertension with dimapres. Studies on the effect of the anti-hypertensive drug dimapres in newly adjusted and pretreated hypertensive patients]. [2013]
Clonidine-chlorthalidone combination once and twice daily in essential hypertension. [2019]
Withdrawal phenomena in subjects with essential hypertension on clonidine or tiamenidine. [2019]
[Clinical trial of a combination preparation of clonidine and cyclothiazide (author's transl)]. [2013]
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