Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mayo Clinic finds effective remedy for blood pressure drop when standing up

05.10.2004


Mayo Clinic neurologists have discovered a drug application smart enough to alleviate orthostatic hypotension -- problems with sinking blood pressure when standing up from a sitting position -- without the unwanted effect of also causing patients’ blood pressure to soar when lying down.



"This is a significant step forward for these patients," says Phillip Low, M.D., Mayo Clinic neurologist and lead study investigator. "This would be a good drug to provide the first line of treatment."

The drug, pyridostigmine, has been used for years for myasthenia gravis, a neuromuscular transmission disorder. Dr. Low hypothesized that it would also improve nerve cell transmission for orthostatic hypotension patients and trigger the reflex that controls blood pressure in all positions.


Of the 58 patients in Dr. Low’s study, one-third were able to stop taking any other orthostatic hypotension medications, and others were able to lower the amount of other drugs needed. Orthostatic hypotension is especially common in those over age 70. In general, blood pressure control lessens as one ages, according to Dr. Low. Common causes of orthostatic hypotension include diabetes, autonomic neuropathy, multiple system atrophy, pure autonomic failure and Parkinson’s disease. Certain drugs, such as diuretics and medication used to control blood pressure, are also common catalysts for the condition. Studies conducted at Mayo Clinic by Peter Dyck, M.D., neurologist, indicate 10 percent of diabetics have orthostatic hypotension.

The challenge with trying to fix this condition, according to Dr. Low, is that most medications that increase blood pressure raise blood pressure in all positions. Thus, the drugs would work for patients with orthostatic hypotension when they stood up, but their blood pressure would be too high when lying down, increasing their risk of stroke. Dr. Low felt that this price was too high, and that treating with medications that raised blood pressure while standing but raised blood pressure while lying down amounted to trading one problem for another.

"We wanted a ’smart drug’ that would only increase blood pressure when standing up, and not when lying down," says Dr. Low. Pyridostigmine works at the level of the autonomic ganglion, which has minimal nerve signaling traffic when lying down. When standing up, however, nerve signaling traffic in the autonomic ganglion increases, so the researchers theorized that a drug that affected the autonomic ganglion would improve orthostatic hypotension patients’ standing blood pressure but not increase the blood pressure while lying down.

After a small, open trial of 15 subjects in which the pyridostigmine performed effectively as hoped, the investigators proceeded to the current double-blinded study of 58 patients. The patients either received placebo, pyridostigmine alone or pyridostigmine in combination with one of two low dosages of midodrine, a drug previously proven to improve orthostatic hypotension.

The effects of the drugs were measured one hour post-treatment. Pyridostigmine significantly improved the patients’ standing blood pressure without elevating blood pressure while lying down. The positive effects of the drug were even further improved when combined with low-dose midodrine. Improvement of blood pressure was associated with improvement of symptoms while standing. Side effects from pyridostigmine were minor and transient, including some abdominal cramping or need to go to the bathroom more often than usual.

Paola Sandroni, M.D., another Mayo Clinic neurologist, conducted a follow-up study of the first 45 patients in the study led by Dr. Low; the follow-up study occurred an average of 19.5 months after the first trial. Detailed information was available on 32 patients, and 75 percent reported either good or excellent results from the pyridostigmine treatment. Approximately one in four were able to manage on pyridostigmine alone, and one in three needed other medications, yet were able to reduce the dose of the other medication (e.g., midodrine or fludrocortisone). "By the time they come to see us at Mayo Clinic, the majority of our orthostatic hypotension patients have had multiple treatments and have not done very well," says Dr. Low. "They are very grateful to have found this drug [pryridostigmine]."

The next step in the orthostatic hypotension research will involve seeking out an even smarter drug combination involving pyridostigmine that might work on multiple levels.

Lisa Lucier | EurekAlert!
Further information:
http://www.mayo.edu

More articles from Health and Medicine:

nachricht New antibody analysis accelerates rational vaccine design
09.08.2018 | Scripps Research Institute

nachricht Distrust of power influences choice of medical procedures
01.08.2018 | Johannes Gutenberg-Universität Mainz

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>