The Effect Of Drugs On Venous Blood Pressure
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Disturbances Of The Heart
Capps and Matthews [Footnote: Capps, J. A., and Matthews, S. A.:
Venous Blood Pressure as influenced by the Drugs Employed in
Cardiovascular Therapy, THE JOURNAL A. M. A., Aug. 9, 1913, p. 388.]
have shown that even with first class preparations of digitalis,
there may be only a moderate gradual rise in arterial pressure, but
not much change in venous pressure. Venous pressure was not much
affected by small doses of ep
nephrin, but with large doses it rose
from 10 to 80 mm. Pituitary extract acts somewhat similarly to
epinephrin. Caffein, though raising the arterial pressure, did not
influence the venous pressure. Strychnin did not raise either
pressure until the dose was sufficient to cause muscular
contractions. They found that the nitrites caused a fall in venous
pressure as well as arterial pressure, although the heart might be
accelerated and more regular. They think that the nitrites act by
depressing the nerve endings in the veins as well as the arteries.
Morphin they found did not act on the venous pressure, although it
lowered arterial tension, in ordinary doses of 1/8 or 1/6 grain; but
with doses of from 1/4 to 1/2 grain, both arterial and venous
pressures were lowered. They found that alcohol in ordinary doses
did not influence the venous pressure, although it lowered the
arterial pressure; but very large doses lowered the arterial and
raised the venous pressure. They think that when the venous pressure
is increased only by large doses of epinephrin, pituitary extract
and alcohol, the effect is due to failure of the heart, although it
may be due to an increase of carbon dioxid in the blood, in other
words, to asphyxia.