Blood Pressure Interaction Between Sildenafil and Sublingual Glyceryl Trinitrate (GTN) in Men With Angina
|First Received Date ICMJE||May 29, 2007|
|Last Updated Date||May 29, 2007|
|Start Date ICMJE||January 2004|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures ICMJE
||Effect of combined sildenafil and GTN on mean maximum reduction in blood pressure|
|Original Primary Outcome Measures ICMJE||Same as current|
|Change History||No Changes Posted|
|Current Secondary Outcome Measures ICMJE||Not Provided|
|Original Secondary Outcome Measures ICMJE||Not Provided|
|Current Other Outcome Measures ICMJE||Not Provided|
|Original Other Outcome Measures ICMJE||Not Provided|
|Brief Title ICMJE||Blood Pressure Interaction Between Sildenafil and Sublingual Glyceryl Trinitrate (GTN) in Men With Angina|
|Official Title ICMJE||Investigation of the Time Course of the Interaction of the Hypotensive Effects of Sildenafil Citrate and Sublingual Glyceryl Trinitrate (GTN) in Men With Stable Angina Pectoris|
|Brief Summary||The purpose of the study is to determine for how long sildenafil potentiates the blood pressure reduction that occurs with glyceryl trinitrate in men with angina.|
By producing a mediator known as cGMP, nitric oxide (NO) potently dilates blood vessels. Nitrates, such as glyceryl trinitrate (GTN), are drugs that release NO (NO donors) and are widely used in the treatment and prevention of angina. Sildenafil is an effective treatment for male penile erectile dysfunction that inhibits the breakdown cGMP. When given alone it causes modest reductions in BP in healthy people and patients with cardiovascular disease. By their synergistic actions, co-administration of NO donors with sildenafil can result in large reductions in BP in patients with angina, a population at increased risk of developing erectile dysfunction. As a result, it is recommended that the two drugs not be co-administered within 24 hours of one another.
Previous studies have defined the effect of nitrates at 60 min after administration of sildenafil, the time of likely maximum interaction. However, emergency medicine physicians would value evidence of a balance of risks from which to make a personal clinical judgement about when they might consider giving GTN in a patient presenting with a severe episode of angina who has recently received sildenafil. Evidence on which to base such a judgement is currently not available. However, we have recently completed a study, showing that the interaction of GTN (0.4 mg spray) after sildenafil (100 mg) lasts less than 4 hours in healthy subjects. Whilst the findings would probably be similar for patients with angina, this question now needs to be investigated directly in order to ensure the generalisability of this work and address an important unresolved clinical issue.
Subjects will be asked to refrain from using short-acting nitrates for 24 hours and long acting nitrates for 72 hours before the start of the study. On the morning of each study visit subjects will take their normal medications, including anti-anginals, as soon as they wake up at home. They will also eat a light breakfast at home before coming to the research unit.
Subjects will attend 4 study visits, each separated by at least 5 days. At study visit 1 GTN will be administered 4 and 8 hours after oral sildenafil or matched placebo. At visit 2 GTN will be administered 4 and 8 hours after the alternative treatment (sildenafil or placebo). The order in which sildenafil and placebo are given will be randomised. At study visit 3 GTN will be administered 1 and 6 hours after sildenafil or placebo. Finally, at visit 4 GTN will be administered 1 and 6 hours after the alternative treatment (sildenafil or placebo). As with visits 1 and 2, the order in which sildenafil and placebo are given will be randomised.
Regular single measures of sitting and standing (after 2 min standing) BP and heart rate (HR) will be recorded at baseline and before and for 40 minutes after each GTN administration. Venous blood samples (20 mL) will be taken at baseline and immediately before and 40 min after each GTN administration for later determination of plasma concentrations of sildenafil and its active metabolite, UK-103,320.
|Study Type ICMJE||Interventional|
|Study Phase||Phase 4|
|Study Design ICMJE||Allocation: Randomized
Endpoint Classification: Pharmacodynamics Study
Intervention Model: Crossover Assignment
Primary Purpose: Treatment
|Condition ICMJE||Angina Pectoris|
|Study Arm (s)||Not Provided|
|Publications *||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Recruitment Status ICMJE||Completed|
|Completion Date||September 2005|
|Primary Completion Date||Not Provided|
|Eligibility Criteria ICMJE||
|Ages||30 Years to 80 Years|
|Accepts Healthy Volunteers||No|
|Contacts ICMJE||Contact information is only displayed when the study is recruiting subjects|
|Listed Location Countries ICMJE||United Kingdom|
|Removed Location Countries|
|NCT Number ICMJE||NCT00479908|
|Other Study ID Numbers ICMJE||LREC/2003/8/35|
|Has Data Monitoring Committee||No|
|Responsible Party||Not Provided|
|Study Sponsor ICMJE||University of Edinburgh|
|Information Provided By||University of Edinburgh|
|Verification Date||May 2007|
ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP