ACE Inhibitor
Summary:
ACE (angiotensin
converting enzyme) inhibitors fall into the class of high blood
pressure medicines (antihypertensives) used to treat high blood pressure
(hypertension).[1] Trandolopril, spiropril and perindopril are ACE
inhibitors that can penetrate the blood-brain barrier.[2]
Anatomical studies in animals and humans have shown that there are
angiotensin type I receptors in the substantia nigra.
People with Parkinson's
disease have fewer angiotensin type 1 receptors in their brains.
Angiotensin II stimulates the release of newly
synthesized dopamine. In examining the relationship between angiotensin type
I receptors and people with Parkinson’s disease, a double-blind,
placebo-controlled, crossover study demonstrated that after a 4-week
treatment period with perindopril (an ACE Inhibitor), “patients had a faster
onset in their motor response to levodopa and a reduction in peak
dyskinesia.”[3]
Potential benefits:
-
Increased “on” time
for people with moderately severe Parkinson's disease
-
Less time with
dyskinesia for people with moderately severe Parkinson's disease
Risks:
-
Possible negative
interactions with other medicines
-
Lower blood
pressure
-
Reduced kidney
function
-
Reduced number of
white blood cells, which can lead to serious infections
Obstacles:
Current
research:
Seven
patients (six women and one man) with moderately severe Parkinson's disease
(Hoen and Yahr scale 3) entered a double blind, placebo-controlled crossover
study. The results confirmed the concept that an ACE
inhibitor can improve the motor response to L-dopa in patients with
Parkinson's disease. The drug also increased the proportion of the day spent
in the 'on' state, and showed an improvement in the functional disability
scale used.[4]
162
people in Japan with mild to moderate Alzheimer's disease and high blood
pressure were divided into three groups for a one-year study. Each group of
trial participants received either a brain-penetrating ACE inhibitor, a
non-brain-penetrating ACE inhibitor, or another type of blood pressure drug.
Trial participants in the brain-penetrating ACE inhibitor groups received
one of two drugs - perindopril or captopril. The study showed that those who
were on a brain-penetrating ACE inhibitor showed less decline in memory than
the other trial participants.[5]
[1]
Angiotensin-converting Enzyme (ACE) Inhibitors; Retrieved date:
March 13, 2005
[2]
A new approach to treating Parkinson's disease? ..Summarized by Robert W.
Griffith, MD
January 30, 2001 (Reviewed: February 18, 2003)
[3]
Potential Noncardiac, Nonrenal Uses of Angiotensin ; from Medscape
Pharmacotherapy
Retrieved date: March 13, 2005 (http://www.medscape.com/viewarticle/438774_10)
[4]
A new approach to treating Parkinson's disease? ..Summarized by Robert W.
Griffith, MD
January 30, 2001 (Reviewed: February 18, 2003)
[5]
Medical News Today; Blood Pressure Drugs May Slow Deterioration of
Alzheimer's
12 Oct 2004
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