Nicotine replacement therapy … - Carlos A ... - Entretiens du Carla

explain why it increases chemoreflex
sensitivity to hypoxia in a population of
non-smokers (13) while this is not the case
in smokers (14). Similarly, NRT does not
significantly modify the heart rate and
blood pressure of hypertensive smokers
whereas it increases the heart rate and
blood pressure of non-smokers (15).
Finally, by the possibility that these
sympathetic effects are due in part to
other constituents of tobacco smoke
(anabasine, beta-carbolines) (10).
Endothelial dysfunction?
Smoking is an essential cause of
endothelial dysfunction, associated with
the risk of arterial spasm, which may occur
for example in the coronary arteries. The
role of nicotine remains controversial (10).
In smokers, endothelial reactivity is
impaired in a comparable way following
exposure to 1 mg of nicotine absorbed
through smoking a cigarette and after
exposure to an equivalent quantity of
nicotine administered with a nasal spray
(16), this route of administration being
very similar to that of cigarette smoke.
However, in non-smokers endothelial
dysfunction is present on exposure to
tobacco smoke but not with oral
administration of nicotine (10).
Finally, endothelial dysfunction could
be related to other components of
tobacco smoke (10).
Table 1.
Experimental data in
patients with CHD?
One study conducted during coronary
angiography analyzed the effects of
nicotine gum on heart rate, blood
pressure and coronary artery diameter
during a cold pressor test in patients with
coronary artery disease (17). NRT does not
potentiate the vasoconstrictive effect of
sympathetic stimulation induced by the
cold pressor test, in terms of either
haemodynamic changes or arterial
diameter.
One study on 36 smokers with
myocardial ischemia carried out exercise
thallium scintigraphy during treatment
with 14-mg then 21-mg nicotine patches,
once for each dose (18). Despite a
significant increase in blood nicotine
levels, associated with the fact that the
patients had not stopped smoking
completely, a significant decrease in
myocardial ischemia was observed. None
of the patients exhibited exacerbation of
myocardial ischemia or coronary events
during NRT. See table 1.
43 Cardiovascular safety of NRTs - Daniel Thomas
(10) Adamopoulos D, Van
de Borne P, Argacha JF.
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and coronary effects of
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Benowitz NL. Doserelated
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endocrine effects of
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(13) Argacha JF, Xhaet O,
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(14) Najem B, Houssière
A, Pathak A et al. Acute
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(15) Tanus-Santos JE,
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(17) Nitenberg A, Antony
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