This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
Synonym. - Night-blooming Cereus. The stems of Cactus Grandiflorus Linne (nat. ord. Cactaceae).
Tropical America; cultivated.
Its branches, or stems, are scandent, diffuse, radicant, slightly 5 to 7 angular; areolae, 5 to 12 spinulose; spinules short, 4 to 6 mm. long, nearly equalling the whorl; flowers large, nocturnal, white, pleasantly and strongly fragrant; the calyx is about 15 to 20 cm. in diameter; the inside being of a splendid yellow, the outside is of a dark brown; the petals of a pure white; and there is a vast number of recurved stamens in the centre.
Constituent. - It is believed to contain an alkaloid, Cactine, but this has not been satisfactorily demonstrated.
Dose, 10 to 30 m.; .60 to 2.00 c.c.
The action of cactus is upon the intra-cardiac ganglia and accelerator nerves, through the cardiac plexus of the sympathetic, and there is not any interference with the inhibitory nerves, nor, indeed, does its administration produce any very marked vasomotor changes. It shortens the ventricular diastole, thus quickening the pulse, and increases the blood-pressure. It is useful in cardiac weakness, that is, relative incompetency; in convalescence from typhoid fever; in simple eccentric cardiac dilatation; in functional cardiac diseases, from tea, coffee, tobacco and alcohol, dyspepsia, neurasthenia of the climacteric, sexual exhaustion; in the "slow heart," from over-stimulation of the pneumogastric or degeneration of the muscular wall of the ventricles. It is of very great use in aortic regurgitation, but is absolutely contra-indicated in mitral stenosis, thus being of value in those cases where the use of digitalis is inadmissible. It has a sphere of action entirely of its own, not, however, replacing other remedies used for cardiac disease, but it is useful in many cases where these drugs are not only dangerous, but absolutely contra-indicated. Failures to obtain results depend upon the fact that many adulterated specimens are found in the shops, or upon the uses of inert, dried material. If made from the green plant, as it should always be, the fluid extract is of peculiar green color.