Source and Composition. The bark of Aspidosperma Quebracho-blanco, (nat. ord. Apocynaceae), an evergreen tree growing in Chili and the Argentine Republic. It is supposed to contain six alkaloids, the most important of which are named Aspidospermine and Quebrachine.
- Extractum Aspidospermatis Fluidum,—Dose, ♏v-ʒj.
- Tinctura Quebracho,—ʒj-iv.
- *Vinum Quebracho,—ʒj-℥j.
Physiological Action. Quebracho has a bitter taste, and in large doses causes severe salivation, nausea, vomiting, vertigo and headache. It lessens the rate of respiration, and seems to decrease the sensation of need for air after active exercise. Of the alkaloids Quebrachine is the most active, but both act similarly upon the lower animals,—affecting the central nervous system, at first by stimulation, which is soon followed by paralysis. The heart and respiration are chiefly affected; at first the fulness and rate of breathing is increased, and the cardiac action slowed; but finally both functions are paralyzed, the cardiac first in warm-blooded animals, the respiration first in cold-blooded ones. Reflex excitability, at first increased, is soon lowered, and the spinal cord is also paralyzed. Locally used these alkaloids paralyze voluntary muscular fibre also, and some of them similarly affect the motor nerve endings.
Therapeutics. Quebracho is extensively used for—
- Dyspnoea, from any cause, in which it is said to be palliative, but as often fails. It may relieve the dyspnoea of asthma, emphysema, bronchitis, etc., but is useless in that due to organic disease of the heart, or in aged subjects of atheroma.
A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.