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Health News Archive 67 - Hypertension
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Pycnogenol® May
Reduce Dosage of Antihypertensive Drug, Nifedipine
Pycnogenol® is a standardized extract
of French maritime pine bark. It contains a variety of flavonoid compounds
with antioxidant and anti-inflammatory properties. Previous animal and
human studies suggest that Pycnogenol may have an impact on blood
pressure. The purpose of this study was to determine if Pycnogenol use
could reduce the dosage of blood pressure medication in people with high
blood pressure.
The authors conducted a randomized, double-blind, placebo-controlled trial
among 58 subjects (33 male, 25 female; average age: 57 years) with
hypertension who were receiving treatment at 3 hospitals in China. They
were randomly assigned to receive either 100 mg Pycnogenol per day or a
placebo in addition to nifedipine, an antihypertensive drug in the class
known as calcium channel blockers, often sold under the trade names Adalat®
(Bayer) and Procardia® (Pfizer). The goal of this study was to determine
whether taking Pycnogenol would allow patients to reduce prescribed
dosages of nifedipine. The individual dosage of nifedipine was adjusted
every 2 weeks over a period of 12 weeks until each participant achieved a
stable blood pressure (no higher than 130 mm Hg). The researchers also
measured several components in the blood to evaluate a potential mechanism
of action for Pycnogenol.
At the end of the 12-week trial, those in the Pycnogenol group needed
approximately 40% less nifedipine medication to control their blood
pressure than those in the placebo group (P<0.001). In the Pycnogenol
group, 22 out of 28 subjects were able to reduce their nifedipine regimen,
16 of them cutting the dosage by half. The Pycnogenol group had
significantly higher blood levels of a particular prostaglandin
(6-ketoprostaglandin F1) that promotes vasodilation (relaxation of blood
vessels) and leads to lower blood pressure (P<0.05). The Pycnogenol group
also had significantly lower (about 20 %) blood concentrations of
endothelin-1 at 4 weeks (P<0.01) and 8 weeks (P<0.05), but not at 12
weeks, than the placebo group. Endothelin-1 is a highly potent compound
that triggers vasoconstriction (constriction of the blood vessels) and
increases blood pressure. Side effects reported for both groups were mild
and transient gastrointestinal problems, nausea, dizziness,
headache, sleepiness. These are the side effects reported for
nifedipine, and there was no statistically significant difference in
adverse side effects between the two groups (39% in the Pycnogenol +
nifedipine group vs. 27% in the placebo + nifedipine group).
Nifedipine is considered a relatively safe drug, with a relatively low
level of adverse side effects reported. These can include headache, upset
stomach, dizziness or lightheadedness, excessive tiredness, flushing
(feeling of warmth), heartburn, fast heartbeat, muscle cramps, enlargement
of gum tissue around teeth, constipation, nasal congestion, cough, and
decreased sexual ability, according to the National Library of Medicine’s
Medline database.1
The researchers believe that Pycnogenol may lower blood pressure by
shifting the balance between vasodilation and vasoconstriction in the
direction of vasodilation. This study demonstrates that Pycnogenol
improves the function of the endothelium (lining of the blood vessels).
The authors suggest that Pycnogenol offers a broad spectrum of protection
for people with high blood pressure.
Source: : Liu X, Wei J, Tan F, Zhou S, Wurthwein G, Rohdewald P.
Pycnogenol®, French maritime pine bark extract, improves endothelial
function of hypertensive patients. Life Sciences. 2004;74:855-862.
Reference:
1. U.S. National Library of Medicine and the National Institutes of
Health. Medline Plus, Drug Information, Nifedipine. Available at:
http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a684028.html#side-effects.
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