Physostigmine (C15H21N3O3 = 273.20), or Eserine, is the principal alkaloid of Physostigma venenosum, an African plant.

Pharmacodynamics.

Central Nervous System. - Physostigmine produces a depression of the cord and medulla; later, of the higher centers.

Muscular System. - Striped muscle is disordered, unstriped muscle is stimulated, through irritation of the peripheral nerve filaments.

Respiration. - Accelerated at first by peripheral irritation; later, slowed and weakened by centric depression.

Heart is slowed by both centric and local action.

Blood-pressure is raised by centric action and by local constriction of the arterioles.

Eye. - Pupil is contracted through stimulation of the filaments to the motor oculi muscle. Ciliary muscle is stimulated.

Alimentary Tract. - Activity of the musculature is stimulated through irritation of the myoneural terminations.

Secretory glands are all greatly stimulated through irritation of the peripheral filaments.

Metabolism. - Apparently little affected.

Temperature. - No constant change noticeable.

Absorption is fairly rapid.

Excretion. - Some physostigmine escapes in the urine, but the greater part is destroyed in the tissues.

Symptoms.

Therapeutic Doses.

Salivation. Perspiration. Slightly slower heart. Gastro-intestinal uneasiness.

Toxic Doses.

Tremors.

Muscular weakness.

Salivation and lachrymation.

Giddiness.

Dyspnea.

Excessive perspiration.

Vomiting and gastralgic pains.

Myosis.

Copious, watery stools.

Weak, slow heart.

Collapse.

Respiratory failure (centric).

Therapeutics.

Physostigmia is used to promote peristalsis in threatening atony. In ophthalmic work it is used to reduce the intraocular pressure attendant on glaucoma.

Dosage.

Extractum Physostigmatis, 0.004 to 0.008 Gm. Tinctura Physostigmatis, 0.3 to 1.2 mil. Physostigminae Salicylas, 0.001 Gm. "Eserine" is another name for Physostigmie.

Physostigmine 69

Crimson = stimulation. Violet = depression.