This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Aspidosperma Quebracho-bianco. Official in Austria, Mexico, Serbia, Spain, Switzerland, and has been incorporated into the U. S. P. IX.
Homeopathic authorities have long claimed that the "mother tincture" of quebracho is an effective remedy in many cases of asthma, stimulating the respiratory center and increasing the oxygen in the blood, and they have given it in dyspnea. Larrion stated that it causes a diminution in the number of pulse-beats per minute and lessens the frequency of the respiratory act. Hale called it "the digitalis of the lungs." There is much more or less conflicting research recorded concerning it.
The most elaborate study of its alkaloids was made by Douglas Cow, and appeared in The Jour. of Pharmacology and Exper. Ther., March, 1914. He studied quebrachine, aspidospermine, quebrach-amine, and aspidosamine, the first-named proving the most toxic; it stimulated the central nervous system, as did the other alkaloids in less degree. The obvious effect was quicker and deeper respiration (not slower) in small dosage. Larger doses had a paralyzing effect on nerve-cells, including the autonomic system, the brain and cord. Still larger doses paralyzed the vagus, the sympathetic and motor nerve-endings. He concluded that it belongs to the curare-nicotine-coniine group of drugs, causing death by respiratory paralysis.
The normal rhythm of the heart is disturbed by quebracho.
The exact indications for quebracho need further study, but it is established that it is of value in asthma and dyspnea not of cardiac origin. It's a bitter which aids the appetite.
The fl. is given in doses of 5 to 30 minims, the latter doses acting very promptly but doing no harm. In severe cases, 60 minims may be given.
Merck's Aspidospermine is given in one- or two-grain doses in pill form.