Duboisia myoporoides, of the Solanaceae.

Preparations

There are no official preparations; but the following can be employed in any of the cases requiring it:

Extractum Duboisive. Dose, gr. 1/6 to gr. 1/2.

Duboisinae Sulphas, or Hydrobromas

Dose, gr. 1/100 to gr. 1/40.

Composition

The important constituent is an alkaloid—duboisine—which possesses the medicinal powers and properties of the plant. It combines with acids to form salts which are freely soluble in water. As regards its chemical relations, duboisine strongly resembles atropine, but differs in some particulars; according to La-denburg, duboisine is identical with hyoscyamine; but here again we have an illustration of the important fact that identity of composition does not necessarily imply identity of physiological action and therapeutical power. The dose of a salt of duboisine is 1/100 to 1/60 of a grain.

Antagonists and Incompatibles

The caustic alkalies destroy the active principle, and consequently prescriptions containing them will be inert, except as to the effects of the alkali. The physiological antagonists are the same as those of atropine; thus physostigmine and muscarine counterbalance the action of duboisine in almost the entire range of power, and opium in a limited degree. Duboisine antagonizes pilocarpine, as respects, at least, the most conspicuous and important properties of the latter. In case of poisoning, emetics and the stomach-pump must be used, and the systemic effects opposed by the subcutaneous use of physostigma, muscarine, or morphine, cautiously, and certainly pilocarpine, further researches having proved the antagonism of the last named.

Synergists

The actions of duboisia are promoted by the other agents of the group, especially by belladonna, stramonium, and hy-oscyamus. The effects of atropine and duboisine correspond to a remarkable extent, but there are points of difference, as follows: Duboisine is twice or more soluble in water than atropine; it has stronger basic properties, and it reacts differently to sulphuric acid and bichromate of potassa; it is less irritating to the conjunctiva, dilates the pupil more promptly, and its effects subside earlier (Gerard).

Physiological Effects

Dryness of the mouth, thirst, and some difficulty in swallowing, soon follow the administration of duboisia, and more speedily after the subcutaneous injection of the alkaloid. The pulse is considerably accelerated; the arterial tension rises, the face flushes, the pupil dilates, and the accommodation is paralyzed. Some frontal headache, tinnitus aurium, giddiness, and restlessness, especially in sleep, are experienced. Certain motor symptoms—uncertain gait, awkwardness of movement in walking, and muscular paresis —occur (Gubler). In animals mental excitement or delirium has been noted, but no confirmatory or opposing observations on man have thus far been reported. The tetanic symptoms which occur after some days in frogs poisoned by atropine, take place under the same conditions from duboisia.

The acceleration of pulse and rise of tension first produced by duboisia do not persist; the pulse-rate and the tension fall after some hours, the excitement subsides, and a condition of stupor comes on which is not sleep, although it favors sleep (Gubler). I can confirm these important observations on the cerebral effects of duboisia.

Therapy

The author has prescribed duboisine in cases of puerperal mania with excitement, on the suggestion of M. Gubler, and with entire success. There is an increase of the maniacal excitement for a few hours after the hypodermatic injection, but this is followed by the condition of stupor and mental calm. The improvement is rapid, and follows so closely the administration of the remedy that he could not doubt it was propter and not merely post hoc.

As respects its use in ophthalmic diseases, it may be stated in general that duboisine is applicable under the same conditions as atropine, to which it is to be preferred, in many cases, it is probable.

The advantages of duboisine, as compared with atropine, are its greater rapidity of action in effecting dilatation of the pupil and paralysis of accommodation, the less irritation of the conjunctiva, and the more rapid recovery from the effects. It is, therefore, much more useful than atropine for determining the refraction of the eye, and for use in ocular therapeutics in general.

Some unpleasant cerebral effects have been observed after instillation into the eye (Seely). The author was given the opportunity, by the kindness of Dr. Seely, to examine the patient—the first instance in which such phenomena were observed—who experienced faintness and strange sensations in the head; but they were entirely subjective and mental, as no change in the circulation or respiration was to be seen. Since that case there have been several examples of the systemic action of duboisine after its instillation into the eye.

To relieve the night-sweats of phthisis and the various neuroses of the respiratory organs, and to stimulate the action of the heart, duboisine may take the place of atropine. As an antagonist to morphine it is equally as effective as atropine, but, as a hypnotic and anodyne, superior to the latter.

Authorities referred to:

Bancroft, Dr. Joseph. The Lancet, March 2, 1878.

Gerrard, Mr. London Medical Record, vol. vi, 1878, p. 156.

Gubler, Prof. A. Bull. Gén. de Thérap., vol. xciv, p. 426.

Lauersau, de, Prof. Bull. Gen. de Thérap., supra, p. 362.

Norris, Prof. W. F. The American Journal of the Medical Sciences. April, 1879, pp. 466, et seq. Duboisia as a Mydriatic, etc.

Ringer, Prof. Sydney. The Lancet, supra.

Seely, Prof. W. W. Lancet and Clinic for 1879, January, February. Various articles on the use of Duboisine.

Tweedy, Mr. John. The Lancet, supra. On the Mydriatic Properties of Duboisia, etc.

Weeker, Dr. L. Bull. Gén. de Thérap., supra, p. 837. De l'emploi compare de l'ese-vine, de l'atropine, et de la duboisine en thérapeutique oculaire.