This section is from the book "A Text-Book Of Pharmacology, Therapeutics And Materia Medica", by T. Lauder Brunton. Also available from Amazon: A text-book of pharmacology, therapeutics and materia medica.
Vascular tonics are substances which cause increased contraction of the arterioles or capillaries. They not only raise the blood-pressure, but influence to a considerable extent the quantity of lymph poured out into the tissues or absorbed from them, and thus modify tissue change. They are of special importance in the treatment of dropsy.
The most important vascular tonics are :Digitalis.