Adrenergic Receptor Modulators for Vascular Function
(STARS Trial)
What You Need to Know Before You Apply
What is the purpose of this trial?
This trial explores how the body's "fight or flight" system affects blood pressure in healthy men and women. It aims to determine if males and females respond differently to signals that influence blood vessels. Participants will receive small doses of medications, including adrenergic receptor modulators such as Isoproterenol Hydrochloride, Norepinephrine Bitartrate, Phentolamine Mesylate (also known as Regitine or Oraverse), Phenylephrine Hydrochloride, and Propranolol Hydrochloride (also known as Inderal), in their arm to observe changes in blood pressure and heart rate. This trial may suit healthy, non-smoking individuals who have avoided caffeine, alcohol, and intense exercise for at least 12 hours. As a Phase 4 trial, the treatment is already FDA-approved and proven effective, aiming to understand how it benefits more patients.
Will I have to stop taking my current medications?
The trial requires you to stop taking any medications that are not taken regularly for at least 12 hours before the study visit. If you are taking beta-agonist inhalers, you must not use them for at least 24 hours before the visit. Also, if you are on medications that interact with the study drugs, like certain antidepressants, you may not be eligible to participate.
What is the safety track record for these treatments?
Research has shown that both propranolol and phentolamine are generally safe. Propranolol, a well-known medication for heart conditions, is usually safe but should not be used by individuals with asthma or certain heart problems. Common side effects include tiredness or dizziness, though these are typically mild.
Phentolamine is used in medical settings, particularly to reverse certain drug effects. Rare reports exist of heart issues when administered intravenously. In this study, researchers will administer the medications in small doses directly into the forearm for short periods, reducing the chance of side effects. Overall, both medications are considered safe when used as directed.12345Why are researchers enthusiastic about this study treatment?
Researchers are excited about these treatments because they specifically target adrenergic receptors in the blood vessels, which are crucial for regulating vascular function. Unlike traditional treatments that may broadly affect blood pressure or heart rate, these treatments allow for precise modulation of α- and β-adrenergic receptors. This could lead to more targeted and effective management of vascular conditions, potentially reducing side effects associated with less targeted therapies. By using drugs like propranolol and phentolamine in combination, researchers hope to uncover new insights into vascular function and improve treatment strategies for related conditions.
What evidence suggests that this trial's treatments could be effective for blood pressure control?
In this trial, propranolol, a beta-blocker, will be used in the β-Adrenergic Blockade arm to lower heart rate and blood pressure by slowing the heart. This medication commonly treats high blood pressure and heart issues. Studies have found that propranolol can increase resistance in blood vessels, aiding in blood flow control.
Phentolamine, used in the α+β-Adrenergic Blockade arm, is an alpha-blocker that widens blood vessels by reducing resistance. It effectively manages high blood pressure by blocking certain stress hormones. Phentolamine is particularly effective at reducing the body's reaction to stress-related chemicals like norepinephrine. Both medications are crucial for understanding and managing blood pressure and blood vessel function.56789Who Is on the Research Team?
Sean van Diepen, MD, MSc
Principal Investigator
University of Alberta
Craig Steinback, PhD
Principal Investigator
University of Alberta
Are You a Good Fit for This Trial?
Healthy males and females aged 18-40, with no history of major diseases, can join this study. Females must be pre-menopausal and not pregnant or breastfeeding. Participants should avoid caffeine, alcohol, strenuous exercise, and certain medications for at least 12 hours before the visit.Inclusion Criteria
Exclusion Criteria
Timeline for a Trial Participant
Screening
Participants are screened for eligibility to participate in the trial
Study Visit
Participants complete a single study visit where various measurements are taken, including blood samples, sympathetic nervous activity, blood pressure, and forearm blood flow.
Follow-up
Participants are monitored for any immediate adverse effects following the study visit.
What Are the Treatments Tested in This Trial?
Interventions
- Isoproterenol Hydrochloride
- Norepinephrine Bitartrate
- Phentolamine Mesylate
- Phenylephrine Hydrochloride
- Propranolol Hydrochloride
Trial Overview
The trial tests how the 'fight or flight' response differs between sexes by using small doses of blood pressure medications in one arm and measuring changes in blood flow. It involves a single visit lasting about 3 hours to assess these responses through various methods including a blood test.
How Is the Trial Designed?
3
Treatment groups
Experimental Treatment
β-adrenoreceptors will be blocked locally in the forearm using propranolol. Normal saline will be co-infused at the calculated rate of phentolamine in the α+β-blockade condition to control for volumetric effects.
α-adrenoreceptors will be blocked locally in the forearm using phentolamine. Propranolol will be co-infused to maintain β-blockade.
Normal saline will be infused through the brachial artery catheter at the same calculated rate as propranolol + phentolamine in the α+β-blockade condition to control for volumetric effects.
Find a Clinic Near You
Who Is Running the Clinical Trial?
University of Alberta
Lead Sponsor
Citations
217064Orig1s000 - accessdata.fda.gov
Phentolamine mesylate is a non-selective alpha-1 and alpha-2 adrenergic antagonist (blocker). Phentolamine is known to inhibit contraction ...
Phentolamine Mesylate: Uses, Side Effects & Dosage
Phentolamine is more effective in antagonizing responses to circulating epinephrine and/or norepinephrine than in antagonizing responses to ...
Therapeutic efficacy of phentolamine in the management of ...
The phentolamine-treated patients exhibited significantly lower CK, CK-MB and cTnI levels, heart rate and SBP than did the control patients (P=0.004, 0.008, 0, ...
Phentolamine: Uses, Interactions, Mechanism of Action
Phentolamine is an alpha-adrenergic blocker used to treat hypertensive episodes, diagnose pheochromocytoma, treat norepinephrine administration site ...
Phentolamine - an overview | ScienceDirect Topics
Systemic vascular resistance is decreased, whereas heart rate, cardiac output, and myocardial oxygen demand are increased during phentolamine administration.
MATERIAL SAFETY DATA SHEET
Environmental Hazards: Phentolamine mesylate is not a DOT hazardous substance according to 49 CFR 172.101. Phentolamine mesylate is not a Marine Pollutant.
MATERIAL SAFETY DATA SHEET - OraVerse
LD50s for Phentolamine Mesylate: 1250 mg/kg oral-rat; 1100 mg/kg oral-mouse; No Observed Adverse Effect Level (NOAEL) 75 mg/kg oral-rat.
Phentolamine mesylate
SWALLOWED ! Accidental ingestion of the material may be harmful; animal experiments indicate that ingestion of less than 150 gram may be fatal or may.
OraVerse (phentolamine mesylate) Injection - eCopy, Inc. - FDA
WARNINGS AND PRECAUTIONS-. Myocardial infarction, cerebrovascular spasm, and cerebrovascular occlusion have been reported to occur following the intravenous or.
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