You can find out more about NPF's National Medical Director, Dr. Michael S. Okun, by also visiting the NPF Center of Excellence, University of Florida Center for Movement Disorders & Neurorestoration.
One of the most common questions we receive on the “Ask the Doctor NPF forum” is how best to address constipation. In patients with Parkinson’s disease, this symptom is both common and disabling. Because of this, there is a critical need for newer and better treatment approaches. In this month’s What’s Hot in PD column, I will review a new drug treatment for constipation and summarize other helpful tips for relieving the condition.
In the May 22, 2012 issue of the journal Neurology, William Ondo, M.D., and colleagues evaluated the efficacy and tolerability of the drug lubiprostone (Amitiza) as a treatment for constipation. In a double-blind, randomized and controlled study, 52 Parkinson’s patients received lubiprostone or placebo (inactive substance) for two weeks and were subsequently followed for four weeks.
Lubiprostone acts by turning on chloride channels in the mucosa of the gastrointestinal tract. It enhances fluid secretion, and improves the overall digestive movement of the stomach and intestines. Furthermore, it does not affect blood electrolytes such as sodium and potassium, making it a very safe treatment.
The study results revealed a “marked or very marked clinical global improvement in 16 of 25 (64%) subjects receiving drug versus 5 of 27 (18.5%) receiving placebo.” Constipation rating scales and stool diaries improved. The adverse event profile was excellent, and loose stools were the most common individual patient complaint.
Under recognized and under treated, constipation is often not addressed even though it affects the majority of Parkinson’s disease sufferers. In the original 1817 essay (An Essay on the Shaking Palsy) describing Parkinson’s disease, constipation was included as an important patient issue, and, unfortunately, almost 200 years later patients still suffer with this problem.
We now know that, in Parkinson’s patients, it takes the stomach longer to empty, and it also takes longer for food to move through the intestines. Muscles and nerves within the gastrointestinal tract are affected by the degenerative process, and interestingly, abnormal protein deposits called Lewy bodies have been discovered in the intestines. Lewy bodies also are found in the brains of Parkinson’s patients, and their presence in the intestines leads us to believe that constipation is likely a core symptom of Parkinson’s disease.
Lubiprostone is a promising advance in the care of Parkinson’s patients. Though it may not work for every sufferer, it should be considered as an option. We recommend that patients employ a comprehensive plan to address constipation. Over the years we have found that the use of many practical therapies (see below), often in combination, to be extremely helpful. Future studies of lubiprostone will need to be longer than four weeks, and should include more information about the type of Parkinson’s patient that most likely will benefit.
Common treatment approaches for constipation in Parkinson’s disease have included:
- Optimization of Parkinson drugs
- Polyethylene glycol
- Fiber supplements
- 6-8 glasses of plain water a day
- Vigorous daily exercise
- Stool softeners
More detailed information on the treatment of Parkinson’s disease constipation is available from two NPF Centers of Excellence.