Picrotoxin or Picrotoxic Acid, is a neutral principle prepared from the seeds of Anamirta paniculata, or Menispermum Cocculus, an Asiatic climbing plant, of the nat. ord. Menispermaceae, the berries of which are called Cocculus Indicus, or Fish-berries. Besides Picrotoxin, the active principle, the shells of the seeds contain two other principles, Menispermin and Paramenispermin, which are inert; also Hypopicrotoxic Acid.
Preparations. There are none official, except Picrotoxin itself.
- Picrotoxinum, gr. 1/40-1/20 in pill by stomach, or gr. 1/60-1/40 hypodermically.
- *Tinctura Cocculi (1 to 8), ♏ij-xv.
- *Planat's Tincture (1 to 4), ♏j-v.
Antagonists. Chloral is antagonistic to its cerebral and spinal actions, but synergistic to its depressing power over the heart and respiration. Acetic Acid gives relief in overdosing, and may have some antidotal power. Anaesthetics antagonize its spasm-producing action.
Physiological Action. Picrotoxin is a cerebro-spinal exaltant, affecting especially the centres in the medulla oblongata, and representing the combined action of Belladonna and Nux Vomica. It causes muscular twitching, incoordination, stupor, delirium, epileptiform convulsions, tonic and clonic spasms, alternating, exalted reflexes, trembling, then coma, insensibility, and death by paralysis of the heart. The drug paralyzes Setschenow's reflex inhibiting centre, and stimulates the reflex centres in the cord. It stimulates all secretions, but especially the intestinal, causes nausea and vomiting, and slows both heart and respiration, after transiently accelerating them.
Cocculus berries are used to adulterate beer, in order to make it more bitter and intoxicant.
Differences between Picrotoxin and Strychnine Spasms. The spasms caused by Picrotoxin are choreic and chiefly affect the flexor muscles ;—those from Strychnine are tetanic, affecting principally the extensors.
Therapeutics. Picrotoxin is used chiefly in nervous diseases.
- Epilepsy,—is amenable to it, especially in cases attributable to onanism, in anaemic subjects, and where the attacks are nocturnal in time.
- Paralyses,—where there is a sense of giddiness, and lightness in the head. It is especially good in paralysis of the sphincters, and in hemiplegia brought on by cold, as facial paralysis, etc.
- Chorea,—is well treated by Picrotoxin, but requires full doses.
- Leucorrhoea,—when the discharge is sero-purulent, with lumbar pains.
- Dysmenorrhoea,—is often benefited by the Tincture of Cocculus commenced two days before the stated period, and continued throughout it.
- Dyspepsia,—with severe epigastric pain, and flatulence,—it is efficient.
- Flatulent Colic,—is singularly amenable to the influence of Cocculus.
- Vomiting, with giddiness, headache, and intolerance of light and sound, —is frequently arrested by Cocculus, when other remedies fail.
- Sweats of Phthisis,— may be arrested for days by Picrotoxin, gr. 1/200-1/100.
- Parasitic Skin Diseases,— Picrotoxin as ointment, gr. x ad ℥j.
- Pediculi,—may be killed by the Ointment, but care should be taken to avoid using it on an abraded surface, lest poisoning result.
A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.