American Materia Medica, Therapeutics and Pharmacognosy

eadily soluble in alcohol, sparingly soluble in water. Dose, 1/150 to 1/30
of a grain.
Physostigmine Sulphate—A crystalline powder, whitish or yellowish
white, changing on exposure to a pink or reddish color, bitter, odorless,
deliquescent; freely soluble in alcohol and water. Kept for preservation in
amber-colored vials. Dose, 1/150 to 1/30 of a grain.
Solutions of one grain of physostigmine or its sulphate to the ounce of
distilled water is used in the eye, one drop three or four times daily.
Physiological Action—The first effect of calabar bean upon internal
administration in overdoses is local—a sense of burning and irritation in
the stomach, with nausea, vomiting and purging. The salivary, gastric
and in testinal secretions are all greatly increased. It stimulates
unstriped muscular fiber, producing in the intestinal canal increased
peristalsis. There is inactivity, prostration, cold, pallid skin and muscular
incapacity.
The evidences of the action of this agent upon the nervous system are not
marked. No pain is produced and the consciousness of the patient is
usually retained. Probably, from deficient oxygenation of the blood, there
is vertigo, which may finally induce narcosis. There are ultimate
paralysis and temporary tetanic convulsions. There is abolition of motor
reflex.
The arterial tension is at first lowered, then increased, the heart is
slowed. There is a reduction in the number and force of the pulsations.
The influence seems to be entirely upon the muscles of the heart,
through overstimulation of the cardiac ganglia, and not through the
central nervous system. The heart finally loses its contractility, is flabby,
and fails in diastole. The respiration becomes slower, is shallow and
feeble, and finally ceases. The heart continues to pulsate with increasing
feebleness for some little time after respiration has ceased. The blood is
loaded with carbonic acid gas, and the corpuscles are altered in their
character.
The general muscular relaxation from this agent is most marked. Small,
long continued doses induce feebleness and indisposition to muscular
exertion. By full doses, tremors of the voluntary muscles are induced,
and finally complete muscular paralysis. The muscular structure of the
Ellingwood’s American Materia Medica, Therapeutics and Pharmacognosy - Page 330