USES OF COCAINE.
The curious property cocaine possesses of producing local anæsthesia
was even noted by the discoverer of the alkaloid—Niemann, who, so
far back as 1860, wrote: “It produces temporary insensibility on
the part of the tongue with which it comes in contact” (Watts’s
Dict., 1st Edition, i. 1059, _ex_ “Ann. Ch. Pharm.” cxiv. 215). This
interesting fact lay dormant until in 1884, Herr Koller, a medical
student in Vienna, was led to test the local anæsthetic action of
the hydrochlorate of the alkaloid, on account of the effect he had
witnessed when cocaine in solution was pencilled upon the pharynx to
render it less susceptible in laryngoscopic examination. A vial of the
solution was given by Herr Koller to Dr. Brettauer, of Trieste, who,
on Sept. 15th, 1884, demonstrated its properties at the meeting of the
Ophthalmological Congress in Heidelberg. Several experiments were made
with the two per cent. solution, which showed that when two drops of
the liquid were placed upon the surface of the normal cornea, and the
application repeated after an interval of ten minutes, at the end of
ten minutes more, the sensibility of the cornea was so far diminished
that it could be pressed with a probe; the cornea and the surface of
the eyeball and eyelids adjoining could be rubbed; a speculum could be
inserted and the lids widely separated, the conjunctiva could even be
seized with fixation forceps, and the eye moved in various directions
without causing the patient notable discomfort.
Besides rendering the superficial structures of the eye anæsthetic,
it is a mydriatic, and produces paralysis of the accommodation, which
passes off sooner than the dilatation of the pupil; this does not at
longest last more than twelve hours. The sensitiveness of the iris is
less affected than that of the surface of the eye. The great excellence
of cocaine consists in the limitation of its action to the tissues to
which it is applied. No doubt, other symptoms at a distance do result
from the external application of the anæsthetic, but they are, for the
most part, insignificant and free from dangerous consequences. In some
measure cocaine may be compared with curare. The one agent paralyses
the termination of the sensory nerves, whilst the other paralyses the
termination of the motor nerves. Cocaine would seem to act in a manner
the reverse of aconite. When applied to a mucous membrane, it has
probably a constricting action on the vessels, produces a blanching of
the part, and simultaneously a deadening of the nervous excitability
which passes into a complete state of anæsthesia; its effect, however,
does not sink deeply into the adjacent tissues, nor does it last long.
This surface application is sufficient to render painless the use of a
caustic, the passage of catheters and lithotrites, or the performance
of operations which do not involve the more deeply-seated tissues.
Such operations as the opening of abscesses and buboes, the removal of
small tumours, require the surface anæsthesia to be supplemented by
two or more hypodermic injections, of a quarter of a grain in each,
of the hydrochlorate in close contiguity to the part to be operated
on. Injected hypodermically, the aqueous solutions of its salts deaden
sensibility around the puncture, so that the deep prick of a pin is
not felt—the surrounding part is reddened, but after thirty minutes it
resumes its normal condition; injected locally, is more useful than
morphine in relieving sciatica. Although solutions of it are little
absorbed by the skin—even a chloroform solution is scarcely at all
absorbed—yet the application of an ointment of the pure alkaloid, made
with lard, or an oily solution of it, to a surface will remove the pain
of inflammation, as in eczema or erysipelas, or the pain of facial
neuralgia or shingles, and the irritation of urticaria or pruritus.
Burns and scalds should first be brushed over with a 4 per cent.
aqueous solution of the hydrochlorate, and the pure alkaloid combined
with carron oil (Linimentum Calcis), petroleum cerate, or boric acid
ointment, afterwards applied on cotton wool or lint. Combined with
boric acid ointment, also, it may be used for fissured nipples, or
for these and stings and bites of insects an aqueous solution may be
applied. The irritability of inflamed mucous surfaces, as in hay-fever,
influenza, coryza, bronchitis, spasmodic asthma, laryngitis, and
pharyngitis, is much relieved by the spray of a watery solution of
a cocaine salt. In obstetrics, its local application relieves the
pain of the dilating os uteri, and diminishes the sensibility of the
perinæum whilst being dilated in first labours; rents of the perinæum
may be stitched up almost painlessly under its action, and under its
influence many minor gynæcological operations are much facilitated by
the ability to insert needles and make small incisions without pain.
The spasmodic and painful affections of the vagina, causing dyspareunia
and vaginismus, may be minimised by vaginal injections of a quarter
of a grain of cocaine in 1 per cent. oily solutions. In dentistry,
it is useful in toothache; it deadens the sensibility of exposed
pulp. The pure alkaloid is preferable to the salts for this purpose,
because, being only slightly soluble in water, it is less liable to
be washed away by the saliva. If a little be inserted in the cavity
of a carious tooth and covered with a plug of mastic solution, all
pain is obtunded for a considerable time. A strong solution in oil of
cloves is also useful. In preparing the cavity, previous to filling,
the sensitiveness of the dentine is more effectively treated by using
a salt of cocaine—either the hydrochlorate or citrate; the latter has
been recommended, as it can be formed into a pellet with the fingers
and pressed into the cavity, but it is not so rich in true alkaloid
as the hydrochlorate; yet, either of these is absorbed more quickly
than the alkaloid itself, which, as before said, is more suitable for
plugging a cavity for some length of time. Before using arsenical paste
to destroy the nerve when exposed, if about a quarter of a grain of a
cocaine salt be inserted into the cavity, after partially clearing,
it will anæsthetize the pulp in about five minutes, and enable the
operator thoroughly to open the cavity and expose the pulp directly
to the action of the arsenical paste without pain to the patient. In
extraction, if a dose be hypodermically injected into the gum on each
side at the base of the tooth, after waiting about five minutes this
may be done almost painlessly, and, if a 50 per cent. aqueous solution
of the hydrochlorate be painted on the surrounding gum, the first pain
of inserting the forceps is annulled. The eye, ear, throat, mouth,
tongue, pharynx, nose, larynx, trachea, urethra, vagina, os uteri,
anus, rectum, and, in fact, the whole mucous membrane, as well as cut
surfaces and open sores, are affected by it, but the true skin is less
so.
Solutions of hydrochlorate of cocaine have been employed topically
in excision of the tonsils, cauterizing the turbinated tissue of the
nose, painting chancres previous to the application of nitric acid or
other caustics, opening abscesses, removing polypi, and many cases
of iridectomy and operation for cataract, squint, and the removal of
foreign bodies from the eye. For the eye an aqueous solution of the
hydrochlorate of cocaine of mostly 2, but sometimes 4, per cent. is
used, and for other purposes from 4 to 20 or even 50 per cent.; of the
weaker solutions it is necessary to repeat the application three to
five times, at intervals of three to five minutes. No operation should
be commenced within at least ten minutes of the first application.
Injurious effects, either local or constitutional, rarely follow
its use. Its action commences in three minutes, increases from ten
to twenty minutes, and mostly disappears within half an hour. The
anæsthesia may be prolonged by applying an Esmarch’s bandage round the
site of injection.
_Uses of Cocaine, and cautions on its employment; a summary of the
experiences of fifty-two surgeons in the United States._ In minor
surgery—is of value in all operations where circulation can be
temporarily arrested in order to prevent undue absorption. A fresh
solution should be employed, of strength not exceeding 4 per cent.
Caution is required when the circulation cannot be controlled. Is of
little use as a local anæsthetic in anal work, such as fistula. In
genito-urinary surgery must be used with care, as it is in this class
of cases that untoward effects have been most marked; the solution
should not remain in contact with mucous surface more than a few
moments. In gynæcological work it is of limited service, as general
anæsthesia is mostly to be preferred. For ophthalmic surgery, Cocaine
is the anæsthetic _par excellence_; in no other department of surgery
is its use so widespread and its application so entirely satisfactory.
It is suitable for all operations on the eyeball, except iridectomy for
acute glaucoma, and enucleation; as it causes dryness of the epithelium
it should not be used long prior to operation. Is of great value in
nasal, aural, and throat operations.—Th. Gaz. Aug. 1891, 518.
=Chloroform and Cocaine Anæsthesia= (_combined_).—Chloroform is
given, 1 to 3 drachms, with an Esmarch’s mask, and from ½ to ¾
grain of cocaine, in 3 to 5 per cent. solution, injected into the
part. Less chloroform suffices, vomiting is rare, and depression on
waking slighter than chloroform alone produces.—L ii./88,220; B.M.J.
ii/88,903. Th. Gaz. Sept. 1888, 630; Oct. 686; Dec. 849.
Equal parts of an 8 per cent. solution and liquor atropinæ sulphatis
form an effective remedy for all painful and inflamed conditions of the
eye; and half a grain of pilocarpine nitrate, added to 1 drachm of a 4
per cent. solution, produces anæsthesia without in the least disturbing
the accommodation.—Whitla.
As regards the toxic properties of cocaine, its effects appear to be
mild and not cumulative. It causes cessation of respiration,—small
doses have an exhilarating effect on the nerve-centres and other parts
of the nervous system. In a case of attempted suicide by an apothecary,
a dose of 1.5 grammes (23 grains) seemed to have no seriously injurious
effect.—Varge’s “Zeitschr.” v.f. 11, 5, p. 222, 1863.
A writer in the _British and Colonial Druggist_, Feb., 1885, p. 36,
thus describes the effect of a full dose:—
“Inasmuch as the writer—whose nervous system is of an almost
unfortunate degree of sensitiveness—has taken doses of the
hydrochlorate, equivalent, in the aggregate, to no less than 32 grains
of cocaine itself within the space of three hours, without (as the
present lines sufficiently prove) a fatal result following, this
remarkable body cannot fairly be classed among the poisonous alkaloids.
Among the chief symptoms induced were increased cerebral activity
mounting at intervals into the region of delirium, the latter tendency
always subservient to a powerful effort of the will. This continued
for five hours, the heart action and breathing being meanwhile
slightly increased, but not to any painful extent. At first the
muscular powers appeared to be enhanced, heavier weights being lifted
without undue stress than is ordinarily the case, while the reflective
faculties—as instanced by ability to read and form conclusions upon
novel scientific matter—seemed stimulated. An hour after the entire
quantity named had been taken, the sensibility of the limbs to external
influences—which had gradually diminished from the first—became
materially lowered, and neither pinches, pricks, nor slight burns with
a heated wire could be felt upon the fleshy portions of the arms or
legs. The trunk, however, never lost its sensibility to pain in any
marked degree.
“Slight convulsive movements and a sensation of bodily torpor
succeeded, giving way about the eighth hour to considerable somnolency.
No special desire, or distaste, for food was noticeable, but sleep
overcame all other symptoms between ten and eleven hours from the
commencement, and continued for thirteen hours afterwards; a slight
feeling of dizziness was experienced on waking, but this gradually wore
off, and had entirely disappeared twenty-four hours later.”
By physiologists, it had been supposed that cocaine would have
properties allied to, if not identical with, caffeine, theme, or
theobromine, in the manner that these themselves are allied. But,
chemically, cocaine is quite distinct; it is much less soluble in water
than caffeine; it is a strong base, which caffeine is not, and its
chemical constitution and derivatives are quite distinct from those of
caffeine. As a medicine, the coca leaf has been more used in France and
America than in England.
Opinions are at present divided as to whether the anæsthesia produced
by Cocaine is the result of vasomotor disturbance—the small vessels are
caused to contract by its application, and the nervous filaments are
doubtless anæmic—or whether Cocaine acts directly as a paralyser on
the nervous endings, whether of sensibility, or touch, or of special
sense, since it removes the power of taste and smell, as well as the
perception of touch and pain. When Cocaine is administered in such
a dose and manner as to affect the whole system, the brain seems to
become excited, the heart stimulated, and blood and pressure increased.
Poisonous doses kill by asphyxia, the breathing becoming arrested and
the heart failing in diastole; but this has not yet been observed in
man, the dose necessary to produce this effect being very large; 20
grains have been taken without very serious result. It diminishes all
the secretions, and, although the intestinal movements are slightly
stimulated at first, larger doses or continued use cause sluggish
action, dyspepsia, and constipation. Tissue change is lessened, and the
amount of urea is similarly diminished; the temperature seems to be
somewhat higher than normal; albuminuria has been found to follow its
use, and sugar has been found in the urine. The kidneys are probably
the special means of its elimination. With regard to its action on
muscular fibre nothing is known, observers being completely at variance
in their opinions.—Buxton, in Ringer’s “Therapeutics,” 12th edition.
“Brown-Séquard regards the effect as a new sample of inhibitory action,
his experiments convincing him that Cocaine acts through the medium of
the peripheral nerves on the nervous centres, which react in bringing
about inhibition of sensibility. The phenomena which result from the
injection of Cocaine at the level of the larynx, he finds to be the
same as those which are consecutive to the application of a jet of
carbonic acid on the mucous membrane of that organ. Two minutes after
the injection there is a generalised anæsthesia and an analgesia of
the different wounds made on the body of the animal. The cutaneous
anæsthesia lasts only a few minutes, but the analgesia of the wounds
persists even till the following day. If fresh wounds are made, these,
far from being analgesic, become, on the contrary, hyperalgesic. That
which proved that Cocaine acts on the nervous centres, and particularly
on the cerebellum, is that injections of this substance produced
sometimes a rolling motion to the side opposite to the injection,
and at others a turning motion. Evidence of the inhibitory action
is offered by another of Brown-Séquard’s experiments: when the dose
of Cocaine injected was large enough to produce convulsions, it was
sufficient to pull or forcibly flex the toes to immediately stop
the convulsions. In animals which died under these conditions the
temperature of the body after death was as high as 44°·4 C, or 111°·6
F.”—Brown-Séquard in Prosser James’ “Guide to New B.P.”
In Vienna, Cocaine has been recommended for use internally in cases of
great exhaustion, such as loss of blood, sunstroke, or diarrhœa, also
by mouth or hypodermically as a cure for morphine and alcohol craving.
Morphine and Cocaine appear to be mutually antagonistic. Cocaine has
been used in some cases of melancholia and insomnia; it also possesses
aphrodisiac properties. It was likewise found to lessen the desire
for sleep and feeling of hunger, and to be a stimulant which quickly
increases and sustains, in a harmless manner, the physical powers of
the body, such as are required in long marches, mountain ascents, &c.,
in dose of ¾ to 1½ grains.
Cocaine is a stomachic, useful after excess either in eating or
drinking, in distaste for food, in sea-sickness and vomiting of
pregnancy, or from other causes; it also improves the condition of the
stomach in atonic indigestion and nervous affections of this organ, as
well as in phthisis and cachectic cases, especially those arising from
the use of mercury.