This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
Antispasmodics are medicinal agents which allay irregular muscular contraction or spasm, and compose the irregular actions of the nervous system, without any special or decided effect on the brain. They are employed in many varieties of mental disturbance, insanity, wakefulness, hypochondriasis, convulsions from teething, spasms from general debility, in which latter case an aromatic stimulant of the circulation and a permanent tonic prove beneficial. In hysteria, dependent upon idiopathic or primary nervous irritation, the use of antispasmodics is indicated. Included in this class are such agents as asafetida, musk, camphor, valerian, galbanum, ammoniac, castor, compound spirit of ether (Hoffman's anodyne), etc.