The dried rhizome and rootlets of Gelsemium nitidum (G. semperrirens)

Characters. - Nearly cylindrical, from 1/2 to 6 inches or more in length, and commonly from 1/4 to 3/4 inch in diameter, with small rootlets attached to, or mixed with, the larger pieces; light yellowish-brown externally, and marked longitudinally by dark purplish lines; fracture splintery; bark thin, presenting silky fibres in its liber, and closely attached to a pale yellow porous woody axis, with evident medullary rays, and with or without pith. Odour somewhat narcotic and aromatic; taste bitter.

Composition. - It contains an alkaloid, gelsemine. Dose. - 5 to 30 grains. 3 R

Preparations.

B.P.

Dose.

Extractum Gelsemii Alcoholicum........................................................

1/2-2 gr.

Tinctura Gelsemii..................................................................................

5-20 min.

U.S.P.

Extractum Gelsemii Fluidum....................................................................

5-20 min.

Tinctura Gelsemii.....................................................................................

1/2-2 1/2 fl. dr.

Action. - When applied to the eye it produces dilatation of the pupil and paralysis of accommodation. It appears to paralyse the sensory columns of the spinal cord, while it excites the motor centres both in the brain and cord. The motor centres themselves become paralysed subsequently. This action causes in frogs paralysis, which is at first accompanied by increased reflex excitability, so that irritation gives rise to tremor or tetanus. Afterwards the reflex excitability completely disappears. In mammals a peculiar affection of the head is noticed, consisting in spasmodic attacks of tremor. The tremor affects the fore feet also and sometimes the hind legs. A kind of ataxia is also observed in the fore legs, which sometimes slip about and sometimes make abnormal running movements. This is succeeded by paralysis of the voluntary muscles and of respiration. The vagus is paralysed, the blood-pressure is diminished, the pulse rapid, and the heart weak. Death occurs from paralysis of the respiration. In man large doses have caused giddiness, double vision, numbness of the fingers, tremor of the head, difficult respiration, nausea, vomiting, and partial paralysis of the tongue and eyes, so that ptosis occurs, and difficulty is felt in moving the eyes or tongue.

Use. - It is chiefly used in cases of neuralgia of the fifth nerve, in toothache, sick headache, and in rheumatism.