New teatment for intractable low blood pressure

Patients are generally pleased with a new Mayo Clinic drug treatment for a common form of impaired nerve transmission that causes dizziness and fainting when patients change position from lying down to standing up, and most want to continue using it.

This finding on patients’ satisfaction of the new drug treatment is especially welcome because drug treatments currently used to treat the dizziness and fainting related to orthostatic hypotension are not free of side effects. The most dangerous side effect of these treatments is increased stress on the heart and increased risk of stroke from high blood pressure when the patient is lying down.

Mayo Clinic’s treatment includes the drug called pyridostigmine (pi-rid-o-STIG-mine), which is commonly used to treat myasthenia gravis, a disorder of the neuromuscular junction resulting in easy fatigability and muscle weakness. Pyridostigmine does not put extra stress on the heart when patients lie down, thus making it a safe treatment. The addition of patient-satisfaction data increases pyridostigmine’s appeal as a possible improved treatment for orthostatic hypotension. Patient satisfaction survey results will be presented by Dr. Paola Sandroni, specialist in neurology and primary author of the study, and colleagues April 28 at the American Academy of Neurology annual meeting in San Francisco.

The patient satisfaction data results from a Mayo Clinic follow-up survey evaluating patient impressions of pyridostigmine. The goal of the drug treatment is to stop the dizziness, light-headedness and fainting that patients experience who suffer from autonomic failure, a common form of impaired nerve transmission which causes orthostatic hypotension. This failure of autonomic nerve function leads to the sudden drop in blood pressure that causes dizziness, fainting or falling. It can be a frequent side effect of Parkinson’s disease, diabetes, chronic alcohol abuse and other conditions. Low blood pressure occurs when a patient suddenly changes body position, from lying down to standing up.

Significance of the Mayo Clinic Finding

Treatment options for orthostatic hypotension are limited because of side effects produced. Most worrisome is their tendency to cause high blood pressure when the patient lies down.

“Using pyridostigmine increases nerve transmission mainly when the patient stands up and not while the patient is lying down. Hence it improves standing blood pressure without increasing blood pressure when the patient is lying down,” says Dr. Sandroni. “This is a big advantage to this treatment, because for the first time, we can offer control of dizziness and fainting without causing a further problem.”

About the Study

To evaluate patient satisfaction, researchers contacted 29 patients by telephone and questioned them in a structured interview. All had previously participated in a well-controlled study to evaluate pyridostigmine’s effectiveness and continued with the drug. Researchers asked specifically about patients’ current symptoms of orthostatic hypotension, including gastrointestinal side effects, and their overall satisfaction with pyridostigmine. Twenty were still taking the drug at the time of the phone interview, and had been for about 19 months. Some took it in combination with other drugs.

Seventeen of the 20 taking pyridostigmine were extremely satisfied with its effects. Nine patients had stopped taking the drug, mostly because they found it wasn’t helpful.

The average age of the patients was 61. Causes of their low blood pressure ranged from general weakening of various physical systems due to age to unspecified failure of the autonomic system, to damage to the autonomic system due to autoimmune disease.

Researchers are encouraged by the results of this follow-up study because it provides more data about successfully treating the disorder. They concluded that pyridostigmine is, overall, well tolerated and can be effective for patients with neurogenic hypotension, as indicated by improvement in symptoms and their desire to continue with the drug.

Background: The Problem of Low Blood Pressure with Posture Change

The change of the body from the lying-down, horizontal position to the standing-up, vertical position is performed effortlessly by most people. The body automatically accommodates this position change by quickly moving most of the blood that needs to be transferred from the chest to the blood vessels of the lower trunk. It does this by speeding up the heart rate and adjusting vessel tension. The remainder of the blood is transferred within three to five minutes. But in patients who have suffered damage to the autonomic nervous system that maintains normal blood pressure, these compensatory pumping and vessel-stress adjustments are not made.

Mayo Clinic: Pioneer in Treatment

The Mayo Clinic pioneered the diagnosis and advanced treatment of autonomic nerve function disorder in 1983 when Phillip Low, M.D., director of the Mayo Autonomic Disorders Project, designed the first laboratory and a comprehensive series of tests for evaluating patients with this disorder. As the first program for autonomic disorders to be funded by the National Institutes of Health, it is currently running three NIH studies.