The Effect Of Drugs On Venous Blood Pressure

Categories: Uncategorized
Sources: 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 epinephrin, 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.