HypertensionNCT01392638
Effects of Sildenafil in Resistant Hypertensives and Genetic Polymorphism
A study testing sugar pill and sildenafil in people with Hypertension, run by University of Campinas, Brazil at 1 site in Brazil.
Trial summary
Sildenafil citrate slightly reduces blood pressure in treated hypertensives patients. However, it is unknown if the simultaneous use of sildenafil plus, at least, 3 classes of antihypertensive agents in patients with resistant arterial hypertension may have a synergic effect on the patients blood pressure. Read more about this study
- Who is it for?
- Ages 35 to 75 years
- Conditions the study is for
- Hypertension
- What is being tested?
- sugar pill and sildenafil
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 120 participants
- Where
- 1 siteBrazil
- Study dates
- Jul 2010to Sep 2012
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 35 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- resistant hypertensive (according to Resistant Hypertension - AHA Statement - 2008);
- compliance with antihypertensive treatment;
- age >35 years;
- diastolic dysfunction
Who cannot join
- valvulopathy
- decompensated heart failure
- important cardiac arrhythmias
- nephropathy
- hepatopathy
- autoimmune disease
Show all 9Show fewer
- tabagism
- decompensated diabetes
- uncontrolled dislipidemia
Trial locations and contacts
1 site in 1 country.
Brazil1 site
Laboratory of Cardiovascular Pharmacology - FCM - Unicamp
Campinas, São Paulo
About this study
Official title: Influence of the Nitric Oxide Synthase T-786C Polymorphism on the Response to Acute Inhibition of Phosphodiesterase 5 in Resistant Hypertension
Sildenafil citrate slightly reduces blood pressure in treated hypertensives patients. However, it is unknown if the simultaneous use of sildenafil plus, at least, 3 classes of antihypertensive agents in patients with resistant arterial hypertension may have a synergic effect on the patients blood pressure. Moreover, sildenafil improves the endogen nitric oxide effects. The nitric oxide is an important signaling molecule in the body that contributes to vessel homeostasis by inhibiting vascular smooth muscle contraction and growth. Hypertension often impaired NO pathways. Nitric oxide is produced by an enzyme, called nitric oxide synthase (NOS3), that show some genetics variants, which means that this enzyme can be different from person to person. Therefore, the objective of the present study is to examine the influence of a genetic variant (known to affect NOS3 levels) in sildenafil acute effects on hemodynamic and cardiovascular function. The investigators hypothesis is that individuals with the genetic variant associated to higher levels of NOS3 will have more benefits from sildenafil treatment.
Read the detailed description
Endothelial dysfunction is one of the mechanisms involved in the maintenance of the high blood pressure levels in resistants hypertensives patients, which is directly related to the NO-GMPc pathway. The phosphodiesterase 5 inhibitor, sildenafil citrate, slightly reduces systolic and diastolic blood pressures in treated hypertensives patients. However, it is unknown if the simultaneous use of sildenafil plus, at least, 3 classes of antihypertensive agents in patients with resistant arterial hypertension may have a synergic effect on the patients blood pressure. Moreover, sildenafil improves the endogen nitric oxide effects produced by eNOS. Therefore, since the genetics polymorphisms of eNOS can affect the NO tissue levels, it seems reasonable to suppose that the acute effects of sildenafil may be modulated by them. Objective: To examine the influence of the T-786C polymorphism of eNOS gene in sildenafil acute effects on hemodynamic and cardiovascular function in resistant hypertensives patients. Casuistics and Methods: Around 120 patients with HAR will be genotyped for the T-786C eNOS polymorphism, from which the investigators will enroll in this study 15 patients with TT genotype and 15 patients with CC genotype. The patients will be monitored with the Portapres system (non-invasive hemodynamic). After basal records of the studied variables, increasing doses of sildenafil will be administrated (37.5, 50.0 e 100.0 mg). Five minutes before each new dose, the studied variables will be recorded again. Hypothesis: The investigators hypothesize that the sildenafil, besides the anti-ischemic effect, will improve the patients hemodynamic status and, moreover, that it will occur a modulation of this effect by the T-786C polymorphism.
- Conditions
- Hypertension
- Being tested
- sugar pill, sildenafil
- Keywords
- Sildenafil, Nitric oxide synthase, Polymorphism, Hemodynamics
- Medical subject headings
- Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
sugar pillOther
Also called No brand name.
Sugar pills: 37.5, 50.0, and 100.0 mg each 30 minutes.
sildenafilDrug
Also called Viagra, Pfizzer Lab., USA
Sildenafil pills: 37.5, 50.0, and 100.0 mg each 30 minutes.
| Study group | Role | What they receive |
|---|---|---|
| sugar pill | Placebo comparator | Intervention: sugar pill Receives: Other: sugar pill |
| sildenafil | Active comparator | Intervention: sildenafil citrate Receives: Drug: sildenafil |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cardiac Output, total peripheral resistance, mean arterial pressure
Hemodynamic measures each 30 minutes
Measured: Each 30 minutes
Secondary outcomes (1)
Left ventricular diastolic function parameters, endothelial function
Assessment of how hemodynamic changes determined by sildenafil would affect endothelial and left ventricular diastolic parameters.
Measured: Pre- and post-sildenafil accumulated doses
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Jul 2011 (estimated)
- Study startJul 2010
- Primary completionJul 2012
- Study completionSep 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypertensionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 120 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Campinas, Brazil
- Sponsor type
- University, hospital or other
- Collaborators
- Fundação de Amparo à Pesquisa do Estado de São Paulo
- Responsible party
- Principal investigator, Heitor Moreno Junior, University of Campinas, Brazil
- Investigators
- Heitor Moreno, PhD, Principal investigator, Faculty of Medical Sciences - Unicamp
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01392638
- Sponsor's protocol ID
- CAAE-0758.0.146.000-09
- Other IDs
- FAPESP
- Status last verified
- Oct 2012
- First submitted
- 25 Jan 2011
- Last updated
- 30 Oct 2012
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Oct 2012. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Influence of the Nitric Oxide Synthase T-786C Polymorphism on the Response to Acute Inhibition of Phosphodiesterase 5 in Resistant Hypertension
- ClinicalTrials.gov ID
- NCT01392638
- Acronym / sponsor ID
- CAAE-0758.0.146.000-09
- Conditions
- Hypertension
- Keywords
- Sildenafil, Nitric oxide synthase, Polymorphism, Hemodynamics
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 120 participants (actual)
- Lead sponsor
- University of Campinas, BrazilUniversity, hospital or other
- Collaborators
- Fundação de Amparo à Pesquisa do Estado de São Paulo
- Study start
- Jul 2010
- Primary completion
- Jul 2012 (actual)
- Study completion
- Sep 2012 (actual)
- First posted
- 12 Jul 2011 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Sildenafil citrate slightly reduces blood pressure in treated hypertensives patients. However, it is unknown if the simultaneous use of sildenafil plus, at least, 3 classes of antihypertensive agents in patients with resistant arterial hypertension may have a synergic effect on the patients blood pressure. Moreover, sildenafil improves the endogen nitric oxide effects. The nitric oxide is an important signaling molecule in the body that contributes to vessel homeostasis by inhibiting vascular smooth muscle contraction and growth. Hypertension often impaired NO pathways. Nitric oxide is produced by an enzyme, called nitric oxide synthase (NOS3), that show some genetics variants, which means that this enzyme can be different from person to person. Therefore, the objective of the present study is to examine the influence of a genetic variant (known to affect NOS3 levels) in sildenafil acute effects on hemodynamic and cardiovascular function. The investigators hypothesis is that individuals with the genetic variant associated to higher levels of NOS3 will have more benefits from sildenafil treatment.
Detailed description
Endothelial dysfunction is one of the mechanisms involved in the maintenance of the high blood pressure levels in resistants hypertensives patients, which is directly related to the NO-GMPc pathway. The phosphodiesterase 5 inhibitor, sildenafil citrate, slightly reduces systolic and diastolic blood pressures in treated hypertensives patients. However, it is unknown if the simultaneous use of sildenafil plus, at least, 3 classes of antihypertensive agents in patients with resistant arterial hypertension may have a synergic effect on the patients blood pressure. Moreover, sildenafil improves the endogen nitric oxide effects produced by eNOS. Therefore, since the genetics polymorphisms of eNOS can affect the NO tissue levels, it seems reasonable to suppose that the acute effects of sildenafil may be modulated by them. Objective: To examine the influence of the T-786C polymorphism of eNOS gene in sildenafil acute effects on hemodynamic and cardiovascular function in resistant hypertensives patients. Casuistics and Methods: Around 120 patients with HAR will be genotyped for the T-786C eNOS polymorphism, from which the investigators will enroll in this study 15 patients with TT genotype and 15 patients with CC genotype. The patients will be monitored with the Portapres system (non-invasive hemodynamic). After basal records of the studied variables, increasing doses of sildenafil will be administrated (37.5, 50.0 e 100.0 mg). Five minutes before each new dose, the studied variables will be recorded again. Hypothesis: The investigators hypothesize that the sildenafil, besides the anti-ischemic effect, will improve the patients hemodynamic status and, moreover, that it will occur a modulation of this effect by the T-786C polymorphism.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| sugar pill | Placebo comparator | Other: sugar pillIntervention: sugar pill |
| sildenafil | Active comparator | Drug: sildenafilIntervention: sildenafil citrate |
Who may qualify
- Ages
- 35 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- resistant hypertensive (according to Resistant Hypertension - AHA Statement - 2008);
- compliance with antihypertensive treatment;
- age >35 years;
- diastolic dysfunction
Key exclusion criteria (9 listed)
- valvulopathy
- decompensated heart failure
- important cardiac arrhythmias
- nephropathy
- hepatopathy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| sugar pillAlso: No brand name.Sugar pills: 37.5, 50.0, and 100.0 mg each 30 minutes. | Other | sugar pill |
| sildenafilAlso: Viagra, Pfizzer Lab., USASildenafil pills: 37.5, 50.0, and 100.0 mg each 30 minutes. | Drug | sildenafil |
Primary outcome
Cardiac Output, total peripheral resistance, mean arterial pressure
Time frame: Each 30 minutes
Hemodynamic measures each 30 minutes
1 secondary outcome
Left ventricular diastolic function parameters, endothelial function
Time frame: Pre- and post-sildenafil accumulated doses
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Oct 2012.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Heitor Moreno, PhD principal investigator
Faculty of Medical Sciences - Unicamp
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing sugar pill and sildenafil in people with Hypertension, run by University of Campinas, Brazil at 1 site in Brazil.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 30 Oct 2012. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Brazil. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cardiac Output, total peripheral resistance, mean arterial pressure (time frame: Each 30 minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Oct 2012.