Clinical Trial: Treatment of Supine Hypertension in Autonomic Failure
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: The Pathophysiology and Treatment of Supine Hypertension in Patients With Autonomic Failure
Brief Summary:
Supine hypertension is a common problem that affects at least 50% of patients with primary autonomic failure. Supine hypertension can be severe, and complicates the treatment of orthostatic hypotension. Drugs used for the treatment of orthostatic hypotension (eg, fludrocortisone and pressor agents), worsen supine hypertension. High blood pressure may also cause target organ damage in this group of patients. The pathophysiologic mechanisms causing supine hypertension in patients with autonomic failure have not been defined.
In a study, we, the investigators at Vanderbilt University, examined 64 patients with AF, 29 with pure autonomic failure (PAF) and 35 with multiple system atrophy (MSA). 66% of patients had supine systolic (systolic blood pressure [SBP] > 150 mmHg) or diastolic (diastolic blood pressure [DBP] > 90 mmHg) hypertension (average blood pressure [BP]: 179 ± 5/89 ± 3 mmHg in 21 PAF and 175 ± 5/92 ± 3 mmHg in 21 MSA patients). Plasma norepinephrine (92 ± 15 pg/mL) and plasma renin activity (0.3 ± 0.05 ng/mL per hour) were very low in a subset of patients with AF and supine hypertension. (Shannon et al., 1997).
Our group has showed that a residual sympathetic function contributes to supine hypertension in patients with severe autonomic failure and that this effect is more prominent in patients with MSA than in those with PAF (Shannon et al., 2000). MSA patients had a marked depressor response to low infusion rates of trimethaphan, a ganglionic blocker; the response in PAF patients was more variable. At 1 mg/min, trimethaphan decreased supine SBP by 67 +/- 8 and 12 +/- 6 mmHg in MSA and PAF patients, respectively (P < 0.0001). MSA patients with supine hypertension also had greater SBP response to oral yohimbine, a central alpha2 receptor blocker, than PAF patients. Plasma nor
Detailed Summary:
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Overnight Medication Trials:
Patients will be studied on the GCRC while in 150 mEq/day sodium balance and on a diet free of substances which interfere with catecholamine determination. Subjects will be asked to use the bathroom to empty their bladder at 8:00 PM. They will be given a randomly chosen medication aliskiren (Tekturna) 150-300mg po, bosentan (Tracleer) 62.5 -125 mg po, captopril 25-50mg po, carbidopa 25-200mg po, clonidine 0.1-0.2mg po, desmopressin 0.2 - 0.6mg po (DDAVP), -diltiazem 30-60 mg po, dipyridamole 200 mg and aspirin 25 mg po (Aggrenox), eplerenone (Inspra) 50-100 mg po, guanfacine (Tenex) 1-3 mg po, hydralazine 10-50 mg po, hydrochlorothiazide 12.5-100 mg po, L- arginine 6-17 g po, losartan 25-100mg po, metoprolol tartrate (Lopressor) 25-100 mg po, nebivolol hydrochloride (Bystolic) 2.5-40 mg po, nitroglycerin-transdermal 0.05-0.2 mg patch, nifedipine (adalat) doses 10-30 mg, prazosin hydrochloride 0.5-1 mg po, sildenafil (Viagra) 25- 100 mg po, tamsulosin hydrochloride (Flomax) 0.4-0.8 mg po. The combination desmopressin 0.2 mg po (DDAVP) and nitroglycerin-transdermal 0.05-0.2 mg. The combinations desmopressin 0.2 mg po and nifedipine (10-30 mg). A placebo pill or skin patch will be done as a control to measure their supine blood pressure without medication intervention. They will then be asked to lie down with the head of the bed elevated 10 degrees. An automated blood pressure cuff (Dinamap) will be wrapped around an upper arm and blood pressure will be measured automatically 2 times in a row every 2 hours. At 8 AM the following morning the study ends. The subjects will then stand at the bedside as motionless as possible for 30 minutes for blood pressure and heart rate determination.
Urine will be collected for 24 hours
Sponsor: Vanderbilt University
Current Primary Outcome: Decrease in supine systolic blood pressure [ Time Frame: 12 hours ]
Original Primary Outcome: Decrease in supine systolic blood pressure
Current Secondary Outcome: Decrease in pressure natriuresis [ Time Frame: 12 hours ]
Original Secondary Outcome: Decreased in pressure natriuresis
Information By: Vanderbilt University Medical Center
Dates:
Date Received: September 14, 2005
Date Started: June 2001
Date Completion:
Last Updated: January 16, 2017
Last Verified: January 2017
