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NEUROLOGIC DISORDERS Jack J.
Chen, Section Advisor
Drug therapy may decrease risk of Parkinson's disease
Key point: Observations from two case-control
studies suggest that statins and calcium-channel blockers may play a
role in preventing Parkinson's disease.
Finer points: Two case-control studies evaluating
the use of statin therapy and antihypertensive therapies, respectively,
and the risk of Parkinson's disease were published simultaneously in the
April 15 issue of Neurology. The first study compared 312 patients
(cases) with idiopathic Parkinson's disease enrolled within 3 years of
initial diagnosis, with 342 age- and gender-matched controls. All of the
study participants were from three rural California counties and
provided information on statin use, including the specific statin
therapy used, duration of treatment, and age at first and last use. The
investigators found that 18.7% of the study participants reported "ever
having taken statins," with a greater number of controls reporting ever
using statin therapy than cases. A protective association between statin
use and risk of Parkinson's disease was noted among controls versus
cases (odds ratio [OR] 0.45 [95% CI 0.29–0.71]), with the greatest
protective association observed in those using statins for 5 years or
more (0.37 [0.18–0.78]). The investigators noted that a 60% to 70%
risk reduction was seen with atorvastatin, simvastatin, and lovastatin;
however, no risk reduction was observed with pravastatin use. The
investigators concluded that additional studies are needed to confirm
the potential neuroprotective role of statins in Parkinson's
disease.
The second study compared 3,637 patients with a first-time diagnosis
of Parkinson's disease with an equal number of well-matched controls.
Data were obtained retrospectively from the United Kingdom–based
General Practice Research Database. Antihypertensive therapy was
assessed for all study participants and classified as current or past
use and according to the number of prescriptions of the relevant study
drugs. The investigators found that current long-term use of calcium
channel blockers (defined as 30 prescriptions or more) was associated
with a significantly reduced risk of Parkinson's disease diagnosis (OR
0.77 [0.63–0.95]), whereas no such risk reduction was observed
with current long-term use of angiotensin-converting enzyme inhibitors,
angiotensin II receptor blockers, or beta blockers.
What you need to know: Some evidence suggests that
statins may have neuroprotective effects by promoting antioxidant
activity, improving endothelial function, and enhancing cerebral blood
flow. Unfortunately, the current literature regarding the
neuroprotective effects of statins is conflicting. Some studies suggest
that statins may have a beneficial effect on Alzheimer's disease,
multiple sclerosis, and Parkinson's disease, whereas other studies
conclude that statins have no benefit to patients with these conditions.
Further complicating the issue are data suggesting that high total
cholesterol in itself is associated with an increased risk of
Parkinson's disease. Calcium channel blockers are theorized to
potentially have neuroprotective effects by inhibiting the
Ca2+-dependent process of apoptosis; as with statins, data
are also conflicting regarding their neuroprotective effects. A
previously published cross-sectional study by Ton and colleagues in 2007
reported no benefit with this class of drugs in preventing Parkinson's
disease. Therefore, the potential neuroprotective effects of statins and
calcium channel blockers need to be examined further before firm
conclusions can be made.
What your patients need to know: As the results of
these two case-control studies are preliminary data, further
well-designed studies are needed to confirm if statins and calcium
channel blockers can reduce the risk of Parkinson's disease.
Sources:
Related resource on www.pharmacist.com:
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