Botanical name: 

Syn.—Atropa belladonna; deadly nightshade.
P. E.—Roots and leaves.
N. O.—Solanaceae.
N. H.—Europe.

Properties: Anodyne, antispasmodic, suppresses secretion.

Physiological action: In full physiological doses it is a cerebral excitant, producing active hyperemia, and a full but active cerebral capillary circulation which manifests itself first by dry throat followed by excitement, exhilaration, dilated pupils, burning of throat, face flushed intolerance of light, impairment of vision, nausea and insomnia. In large toxic doses above symptoms are aggravated, followed by incoordination of muscles, motor paralysis, difficult deglutition, wild and furious delirium, muscular twitching, a scarlet rash appears on the body, pulse becomes feeble, general prostration, deep coma, convulsions and death from paralysis of the inhibitory nerves of the heart, and later the heart muscles. At first contracts the blood vessels in the cord, increasing arterial tension, then, as its paralyzing effect is manifested, it dilates the blood vessels and reduces pressure. On account of overstimulation of the capillaries exudation takes place, resulting in the characteristic scarlet rash. The powerful determination of blood to the face and head causes flushed face. Dilation of the pupil causes the intolerance of light as well as impairment of vision. Belladonna is a powerful vaso-motor stimulant, paralysis from overstimulation results when given in large doses. Indication: Dullness, drowsiness, eyes dull, dilated pupils, dullness of mind and tendency to, sleep, impaired capillary circulation of skin. Blueness of face and extremities, coldness of hands and feet, cerebral congestion. Pain in head, heavy, tense and sleepy, showing that it is the remedy in passive congestion, especially of the cerebro-spinal centers.

Use: It is a direct sedative in fevers, but combats fever processes. Induces powerful capillary circulation. The influence is extended from the nerve center to the periphery, and, if given in overdoses, stimulates the capillaries so abnormally as to produce a red rash. It antagonizes congestion. Its influence in restraining secretion does not prevent its use in capillary stasis. If used in small doses its influence on the circulation precedes that of secretion, as its first influence is on circulation, then on secretion. Combined with aconite the action of restraining secretion is not nearly so marked in inflammatory conditions. If given early with aconite when there is fever only the hyperemia and consequent inflammation is abated. It is our most important remedy in equalizing the circulation and preventing local hyperemia, which is essential to all local inflammatory action. It is a powerful vaso-motor stimulant; stimulating capillary circulation. It has a direct action on the heart, increasing its action, slowing and strengthening the pulse. In urinary affections the result of capillary congestion, with perhaps throbbing pain in the back in the region of the kidneys, it is a good remedy. In sore throat, where the mucous membrane is dry and swollen we think of belladonna. Spasms of the orifices of the body of a passive nature are relieved by it. In incontinence of urine, especially in children, it is an effective remedy if indicated, but we generally succeed in overcoming this condition with other less powerful remedies.

The Materia Medica and Clinical Therapeutics, 1905, was written by Fred J. Petersen, M.D.