9. Extractum Aconiti Rad.—Not officinal. Prepared with alcohol. Dose, half a grain.
Fatal Dose of Aconitia.—Smallest: in one case 1/50 of a grain nearly proved fatal (Pereira). The tenth and even twentieth of a grain are believed to have caused death (Headland; Herapath). The average quantity for an adult is probably between 1/16 and 1/20 of a grain. One drachm of the root, four grains of the alcoholic extract, and one drachm of the tincture have proved fatal.[224] Numerous well-authenticated cases are on record of aconite root being scraped and eaten at table, in mistake for horseradish, with very serious and even fatal results.[225] (See Guy and Ferrier’s For. Med., p. 617.)
Fatal Period.—The shortest time in which death has been known to occur is 1¼ hour: the longest, 20 hours: average, less than 4 hours (Guy and Ferrier). A case is mentioned in Woodman and Tidy’s Forensic Medicine, however, in which death occurred in 20 minutes. “The symptoms usually make their appearance in from a few minutes to one or two hours; whilst death usually takes place within three or four hours” (W. and T., p. 393).
PHYSIOLOGICAL EFFECTS.
Aconite produces, locally applied, a tingling sensation, followed by numbness, and the earliest symptom of poisoning by aconite, when any one of its preparations has been taken by the mouth, is tingling, followed by numbness and anæsthesia of the lips and throat, afterwards becoming general. Vomiting occurs frequently, but not universally: purging is not nearly so frequent (W. and T.). The intellectual faculties are usually unaffected, but in some cases there is stupor. Aconite paralyses both the reflex and motor activity of the spinal cord, hence there is an almost total loss of muscular power. The respiratory centre is eventually paralysed, so that death may result from suffocation (Farquharson). The heart’s action becomes feeble and irregular; its rapidity is first diminished, then increased. The face is pale, and the body bathed in a clammy sweat: the pupils “are at first contracted, and afterwards dilated shortly before death.” The respiration becomes slower, then irregular, and death generally results from its cessation (asphyxia).
In cases of poisoning by aconite, death may be caused by (1) asphyxia, (2) shock, or (3) syncope.
The following symptoms were noted in the case of a cat, to which one-tenth of a grain of Morson’s English aconitia (= pseudaconitia, or nepaline) was administered:—stertorous and difficult breathing, staggering motions, convulsions (always contracting, never stretching like strychnia), vomiting, foaming at the mouth, moans and spasmodic cries, violent struggles for breath; the body fell over on one side, the limbs were stretched forward and worked spasmodically, but never stiffened. Attacks intermittent, with peaceful intervals. Involuntary defecation; retching (the stomach had already emptied itself), prolonged low moans, gasps for breath, abdominal rumblings, insensibility for two hours with occasional twitching, moans and cries. Eyes wide open, pupils not contracted. Finally, after 2½ hours, a few slight struggles, a convulsive gasp, and death. Stiffening very slow. Tongue protruded beyond the teeth.
Twelve hours after death, the rigidity was very strong. A post-mortem examination was then made, with the following results. Pupils dilated. Intestines and other organs normal, not congested: lungs collapsed and congested: heart very much venously congested. Blood not more fluid than usual. Larynx filled with frothy mucus. Brain congested.
On analysis of the stomach and other organs an alkaloidal extract was obtained, which, when submitted to the taste test, produced all the effects characteristic of aconitia. It is worthy of remark that the colour-tests completely failed.
Treatment and antidotes.—“Emetics, stimulants internal and external” (Squire’s Comp. B. P.). No chemical antidote is known: animal charcoal has been recommended, but its efficacy is doubtful. A mustard emetic should be applied, followed by the stomach-pump. “In the latter stages, depletion from a jugular vein to relieve the distension of the right heart, accompanied by the most persevering efforts to promote the expansion of the chest.” Gentle magneto-electric currents down the back of the neck and around the margin of the ribs, to excite contractions of the diaphragm, accompanied by rhythmical abductions of the upper extremities, should be employed. If there is yet a capability of swallowing, brandy and ammonia should be given (Royle’s Mat. Med.).