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640 LOCAL ANESTHETICS AND TOOTH EXTRACTION.

•A formidable list of casualties ^rew. ivepoi'ls of cases of respiratory
and of cardiac paralysis foUowiiii;" its ein|)I<)yinent were not uncommon.
It apparently needed disaster to demonstrate that cocain helonj^cd in the
category of actively poisonous alkaloids, being by no means the bland
and safe agent many operators seemed to think it. This lesson, learned
at great cost, is one the operator is ever to heed, particularly in the
hypodermatic employment of the agent. J)r. JNI. JI. Cryer has re-
ported^ cases of ascending degeneration of the trunks of the maxillary
nerves following upon cocain injections about the jaws.
For the origin, composition, physiological effects, and toxicology of
the drug the student is referred to the standard works upon materia
niedica. There are several points, however, which cannot be over-
emphasized, the first being in regard to the drug itself. A full dose of
cocain hydrochlorid by the stomach is about gr. f . The composition
of the commercial specimens is not constant ; some of them appear to
contain the actively poisonous alkaloid isatropylcocain. A safe dose
when applied hypodermatically is not in excess of gr. \.
The lethal effect of cocain is upon the res})iratory centre. Its
absorption is followed by a stimulation of the cardiac and respira-
tory functions, which is commonly followed by a reaction, the stimu-
lation giving way to depression. Idiosyncrasies as to the effects of
cocain are common ; cases of susceptible women have been noted in
which gr. produced toxic effects. It is to be noted that the depres-
\
sion following as a secondary effect upon the primary stimulation may
not occur for an hour or later.
In prescribing cocain for hypodermatic injection, the analgesic is
the first element to be considered in the prescription. The dose is not
to exceed gr. l. The second factor demanding attention is a physio-
logical antidote, one which Avill not neutralize the analgesic effect and
yet will prevent the toxic action of the cocain upon the cardiac and
respiratory functions. Morphin is that agent. As its full physiological
effect is not required, a small dose, gr. ^, will be sufficient. The next
ingredient of the prescription is an agent which shall prevent abrupt
spastic contraction of the arteries and heart. Trinitrin is this agent.
One drop of the 1 per cent, solution is the indicated dose.
Fungi develop freely in solutions of cocain, so that if the pre-
scription is to be a permanent solution, an antiseptic is required to
prevent decomposition. Cinnamic alcohol answers well for this pur-
pose. One drop of carbolic acid to each half-grain of cocain is an
efficient antiseptic. By boiling cocain is split up into methyl, benzoic
acid, and ecgonin, so that cocain solutions cannot be sterilized by
boiling.
' Proc. Academy of Stomatology, Philadelphia, 1896.