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Mineral acids and alum are injurious to the teeth if used for a
long time, and iron is liable to stain them ; therefore these sub-
stances are best taken through a [glass tube,] and should not be
used as gargles for long [periods.]

Toothache may be relieved by local anodynes, as creosote, or
[pure] carbolic acid. The tooth is plugged with [absorbent]
cotton soaked in one of these. A piece of clean cotton must be
placed over the carbolized cotton to prevent the carbolic acid
from reaching the mouth. This method may damage the tooth-
pulp.

B. Drugs acting on the Salivary Gland. Much atten-
tion has been devoted to the submaxillary gland of the dog, and
there is no reason for supposing that the other salivary glands



8O PHARMACOLOGY AND THERAPEUTICS.

of that animal or of other creatures, differ markedly from it. We
know that the submaxillary gland is under the influence of the
chorda tympani nerve, which contains vaso-dilator fibres, and
also some which directly modify the secretion of the gland apart
from the secondary effects, due to the alterations in the vessels,
obtained when the chorda tympani is stimulated. This nerve
has its centre in the medulla, and is capable of being excited re-
flexly by stimulation of many nerves, even the sciatic, but espe-
cially by stimulation of the gastric branches of the vagus, and
by the terminations in the tongue and mouth of the glosso-
pharyngeal and gustatory nerves. The gland is also supplied
with sympathetic branches which proceed from the cervical
sympathetic trunk ; these are vaso-constrictor, and can also
modify the quality of the secretion ; but we do not know so
much about them as we do about the chorda tympani. Drugs
which increase the amount of saliva have been called sia-
logogues ; those which decrease it, anti-sialogogues. It is
clear that there are very many ways in which each of these might
act, but here it will suffice to enumerate only those ways in which
they are known to act.

i . Sialogogues acting either on the secretory cells or upon the
terminations of the nerves in them. Of these [pilocarpus] has
been most studied, and by means of the experiments it has been
proved to act either on the cells themselves or the terminations
of the nerves in them. It acts equally well after section of all
the nerves going to the gland. It acts when it is injected directly
into the gland, but is prevented from reaching the general cir-
culation. If it has been given, stimulation of the chorda or of
the sympathetic produces no more effect on the amount of secre-
tion than can be easily explained by the vascular effects.



Sialogogues falling under this heading are



(1) Pilocarpus.

(2) Muscarine.

(3) Iodine compounds.



(4) Mercury.

(5) Nicotine.

(6) Physostigmine.



The last two probably act also by stimulating the centre in the medulla,
for section of the chorda tympani decidedly lessens the secretion caused by



DRUGS ACTING ON THE DIGESTIVE APPARATUS. 8 1

them. Physostigmine soon ceases to cause an increase of the secretion, for it
tightly contracts the vessels of the gland.

2 . Sialogogiies acting reflexly by stimulating the peripheral ends
of afferent nerves. Of these there are two important varieties :

(a) Those stimulating the gustatory and glosso-pharyngeal nerves in the
mouth :



(1) All Acids and

(2) Acid Salts.

(3) Chloroform.

(4) Alcohol.



(5) Ether.

(6) All pungent substances, as

mustard, ginger, etc.



(b) Those stimulating the vagus in the stomach :

Most emetics, especially Antimony and Ipecacuanha.

3. Anti-sialogogties acting either on the secreting cells or the
terminations of the nerves in them. Of these atropine has been
most studied, and it is proved to act directly on the gland by the
fact that the administration of it prevents any increase of salivary
secretion on stimulation of the chorda, although the vessels dilate
as usual. It is highly probable that it acts upon the nerve ter-
minations, because, even after considerable doses, quite para-
lyzing the secretion of chorda tympani saliva, stimulation of the
sympathetic will still induce secretion.

Anti-sialogogues falling under this heading are



(1) Belladonna.

(2) Hyoscyamus.



(3) Stramonium, and

(4) Nicotine in excess.



4. Anti-sialogogues acting reflexly by depressing the peripheral
ends of afferent nerves. Alkalies, opium, and any substances
which allay irritation of the mouth. Part of the effect of opium
is due to its depressing action on the medullary centre.

Therapeutics. A deficiency in the amount of saliva
secreted is seen most markedly in fever, when the mouth becomes
very dry, and the patient complains of thirst. Sometimes it is a
disease in itself, and the origin of this malady is then probably
nervous. It is a prominent symptom of belladonna poisoning.
In fever, acid drinks, especially those containing carbon dioxide
gas, lemonade, etc., are of use as sialogogues. Drinks which

6



82 PHARMACOLOGY AND THERAPEUTICS.

relieve this febrile thirst are called Refrigerants. For [the con-
dition known as] " dry mouth " [pilocarpus] has been used, and
it will relieve the dryness due to belladonna poisoning. Excessive
salivary secretion is hardly met with except as a symptom of poi-
soning, especially by mercury, [iodine or pilocarpus] . In some
forms of indigestion the saliva has a very unpleasant taste, and
may even be diminished in quantity, but then the indication is to
treat the indigestion.

C. Drugs acting on the Stomach. Strictly speaking,
we ought to consider these under the following heads : (0). Those
drugs which, by modifying the secretion of hydrochloric acid or
pepsin, influence the conversion of proteids into peptones and
albumoses. (<5). Those which influence the property possessed
by the gastric juice of curdling milk. (V). Those which affect
its antiseptic power by modifying the secretion of acid. (</).
Those which modify the secretion of mucus. (*?). Those which
influence the nerves, the vessels, or the movements of the stom-
ach. (/). Lastly, those which are emetics. Our knowledge,
however, is not sufficient to enable us to do this, and the most
useful classification is into those affecting the secretion of gastric
juice as a whole, the secreted contents, the vessels, the nerves,
the movements, and emetics.

i. Drugs increasing the amount of gastric juice secreted.
These are usually called Stomachics, and include a great many
substances. Stimulants to the mouth reflexly increase the secre-
tion of gastric juice ; all bitter and aromatic substances act in
this way, and they also increase the appetite. The mere presence
of food in the stomach stimulates the gastric flow. Probably
aromatics and bitters act also on the stomach itself.

The drugs which increase the flow of gastric juice are



(1) Aromatics.

(2) Bitters.

(3) All alkalies (especially potas-

sium and sodium bicarbon-
ates, and Spiritus Ammoniac
Aromaticus).

(4) Alcohol.



(5) Ether.

(6) Chloroform.

(7) Magnesia.

(8) Magnesium carbonate.

(9) Pungent substances (pep-

per, mustard, horse-radish).



DRUGS ACTING ON THE DIGESTIVE APPARATUS. 83

Therapeutics. Stomachics are very largely used for the
purpose of increasing the secretion of gastric juice in cases of
dyspepsia.

2. Drugs decreasing the amount of gastric juice secreted.



(1) Mineral acids.

(2) Acetic acid.



(3) Many of those in the last list if
given in large doses, e.g.,
alcohol, ether and chloroform.



Therapeutics. These drugs are never employed for this
effect. It is particularly to be observed that while alkalies
increase the secretion of the gastric juice, which is acid, they
diminish that of the saliva, which is alkaline ; but acids increase
the secretion of the alkaline saliva, but diminish that of the acid
gastric juice.

3. Drugs altering the composition of the gastric contents.
Acids and alkalies naturally modify the reaction of the gastric
contents. For this purpose diluted mineral acids are often pre-
scribed to be taken about two hours after a meal, in cases in
which the cause of indigestion is thought to be that the amount
of hydrochloric acid secreted is deficient. If the acid were given
at meal-time it would prevent the secretion of the natural acid ;
but by giving it after the meal, when all the acid that the gastric
juice is capable of forming has been secreted, the drug carries
on the act of digestion. In case of indigestion in which, from
the nature of vomited matters or from any other reason, it is con-
sidered that there is an excess of acid in the stomach, alkalies are
given at meal-times, the favorite drug being sodium bicarbonate.

Pepsin is given, usually in combination with diluted hydro-
chloric acid, when it is probable that the cause of the indigestion
is the secretion of too small an amount of pepsin ; but in this,
as in every other variety of dyspepsia, it is far more important
to remove the cause of indigestion than to endeavor to modify
the composition of the secreted gastric juice.

Many attempts have been made to try, by the administration
of antiseptics, to prevent fermentation and putrefaction from
going on in the stomach, but with a limited success, for a suffi-
cient dose of any antiseptic [may be] frequently deleterious.



84 PHARMACOLOGY AND THERAPEUTICS.

Here, even more than in the last case, the right treatment is to
remove the cause of the putrefaction.

Drugs that have been used for this purpose are



(1) Carbolic acid.

(2) I o do form.

(3) Boric acid.

(4) Creosote.

(5) Eucalyptus.

(6) Thymol.

(7) [Resorcin.]



(8) [Salicin.

(9) Bismuth salicylate.]

(10) Salol.

(11) Sodium hyposulphite.

(12) Sodium sulpho-carbolate.

(13) Sulphurous Anhydride.

(14) Naphtol.



Charcoal has been employed, but when it is moist it is useless.

4. Drugs which dilate the vessels of the stomach. The vessels
of the stomach are very sensitive to irritation. They easily dilate
upon mechanical irritation, and the presence of food, especially
peptones, causes the vascularity of the mucous membrane to in-
crease. Within limits greater vascularity is an advantage, for it
not only favors the secretion of gastric juice, but it facilitates
absorption.

The substances which increase the vascularity of the stomach
are all stomachics (except alkalies), diluted mineral acids, the
drugs which have been already enumerated as irritants generally,
and squill, digitalis, colchicum, senega, copaiba, gamboge, guai-
acum, and veratrine. This is a very long list, and many of the
substances in it are never employed for their irritant effect ; in
fact, the only ones in common use are the stomachics ; the others
are far too powerful ; even small doses of them set up inflammation
of the gastric wall, which is also produced by over indulgence in
stomachics, as we constantly see in the gastritis induced by alco-
hol. The therapeutic indications for this class of drugs are the
same as those for stomachics generally.

Gastro-intestinal irritants. In describing the individual ac-
tions of drugs the statement is frequently made that they are
gastro-intestinal irritants, and this is a convenient opportunity
for describing the symptoms produced in health by these drugs.
If the drug has a caustic action, as many gastro-intestinal irri-
tants have, the swallowing of it will cause considerable pain in



DRUGS ACTING ON THE DIGESTIVE APPARATUS. 85

the mouth and pharynx ; in a short time these parts will become
severely inflamed, and consequently very much reddened, swol-
len and painful. The tongue will be often much enlarged. If
the drug is corrosive, sloughs, generally white in color at first,
with a severely inflamed area around them, will be seen ; as they
fall off they will leave ulcers. Owing to the pain and swelling,
it will for some time be impossible to take any food, or at the
best only that of a soft or fluid nature. Directly [after] the
drug reaches the stomach, intense irritation is set up ; conse-
quently the patient feels severe abdominal pain, and there is vio-
lent retching and vomiting. As the poison passes on, it pro-
duces its severe irritant effects on the intestine, and diarrhoea
sets in. Both the vomited matters and the motions often con-
tain blood. The general symptoms are an anxious countenance,
small feeble pulse, scanty urine, a low temperature, and all the
symptoms of collapse. Later on, the gastro-intestinal irritation
may be severe enough to set up general peritonitis, or a gastric
ulcer may form, and then there may be added to the case all the
symptoms of gastric ulcer and its sequelae. The inflammation
of the resophagus may lead to its contraction. At the post-
mortem examination, if the patient has died soon after the ad-
ministration of the poison, the stomach will be very red and
ecchymosed, with a swollen mucous membrane. Parts of the
intestine will be in the same condition. This severe inflamma-
tion may, in many places, have led to the formation of sloughs.
It must be remembered that many gastro-intestinal irritants have
no action on the mouth.

5. Drugs which contract the gastric vessels. These are the
same as those which have already been enumerated as being
generally astringent. They are much used, more for the intestine
than the stomach, and will therefore be considered in detail
presently. (Seep. 95.)

6. Drugs acting on the nerves of the stomach. All drugs
powerfully irritant to the stomach cause pain in it ; those that
are only slightly irritant give rise to a sensation of warmth. It
is never desired to produce gastric pain'.

Gastric sedatives. These drugs are the same as those which



86 PHARMACOLOGY AND THERAPEUTICS.

are local sedatives to other parts of the body. Those most used
for the stomach are



(1) Bismuth subcarbonate.

(2) Bismuth subnitrate.

(3) Bismuth salicylate.

(4) Opium.

(5) Hydrocyanic acid.



(6) Carbon [dioxide.]

(7) Ice.

(8) Belladonna.

(9) Hyoscyamus.
(10) Stramonium.



They are employed in the Very many painful forms of dyspepsia.

All, except perhaps stramonium, are in frequent use.

7. Drugs acting on the movements of the stomach. It has been
observed that the movements of the stomach increase as the acidity
of the contents increases. If it be that the acidity is the cause
of the movements, anything which causes an increase of acidity
will lead to more powerful movements. Apart from this, strych-
nine appears directly to stimulate the [unstriped] muscle of the
gastric wall. Stomachics also probably aid the movements, so
that our complete list will be mineral acids, nux vomica, and the
stomachics.

The proper churning up of the gastric contents is so necessary,
that the value in dyspepsia, of drugs which aid the gastric move-
ments, is very great. Hence the frequency with which nux
vomica enters into anti-dyspeptic acid mixtures.

Carminatives. This term is often applied to substances which
aid the expulsion of gas from the stomach and intestines. They
act by stimulating the gastric and intestinal movements. It has
been found from clinical observation that the most efficient car-
minatives are



(1) Stomachics generally, espe-

cially

(2) Aromatics,

(3) Bitters,

(4) Pungent substances,



(5) Asafoetida,

(6) Ammoniacum,

(7) Valerian,

(8) Camphor and

(9) Volatile oils.



8. Emetics. It is well known that the many complicated
mechanisms involved in the act of vomiting are under the con-
trol of a centre in the medulla, which is capable of being stimu-
lated by afferent impulses reaching it from many sources, such as



DRUGS ACTING ON THE DIGESTIVE APPARATUS. 87

the cerebrum, as when sights or smells cause sickness, the mouth,
the pharynx, the oesophagus, the lungs, the heart, the stomach,
the intestines, the biliary passages, the kidney, the peritoneum,
and the uterus ; so that the drugs acting on any of these organs,
or on the centre itself, might be emetics. But it is usual, in
describing drugs which cause vomiting, to mention only those
which do so either by acting on the stomach or on the centre in
the medulla, and they are divided into two corresponding classes.
Those acting on the stomach are sometimes called direct emetics,
because they act directly on the stomach ; and those influencing
the medulla are called indirect; but some authors reserve the
word direct for those acting on the medulla, and speak of those
affecting the stomach as indirect. Considering this confusion,
it is better to divide emetics into gastric and central. By means
of the following experiments we determine to which group any
drug belongs :

(1) The emetic is injected directly into the circulation. If
very shortly after this vomiting takes place, the drug must have
acted on the medulla, to which it has been carried by the circu-
lation ; but if some time elapses we conclude it acted on the
stomach, and that it was first excreted into this organ before
vomiting took place. This experiment may be made still more
striking by injecting directly into the carotid, for then the
medulla is quickly reached.

(2) If the least quantity of the drug which, when injected
into the circulation, will produce vomiting is larger than is neces-
sary when it is introduced directly into the stomach, the infer-
ence is that the drug acts primarily on the stomach, and that
when it produces vomiting after injection into the circulation it
only does so because some of it has been excreted into the
stomach.

(3) If the drug will not produce vomiting after injection into
the circulation when the stomach is replaced by a bladder, it
shows that it acted directly on the stomach ; but if vomiting is
produced it shows that the drug acted on the medulla, and that
the vomiting is caused by the contraction of the abdominal
muscles.



88 PHARMACOLOGY AND THERAPEUTICS.

(4) If the drug takes a long while to act after its introduction
into the stomach, it probably acts centrally ; and the reason for
the delay is that sufficient time must elapse for the drug to be
absorbed.

In spite of these experiments it is difficult to be sure about
the action of emetics, for some act in both ways, and some may,
in the course of their circulation through the blood, act upon
some of the many parts of the body from which the vomiting
centre receives afferent impulses.

The following is a list of those emetics which are commonly used.
Emetics acting on the stomach :



(1) [Yellow mercuric subsul-

phate.]

(2) Alum.

(3) Ammonium carbonate.



(5) Zinc sulphate.

(6) Sodium chloride.

(7) Mustard.

(8) Warm water.



(4) Copper sulphate.
Of these zinc and copper sulphate act slightly on the medulla.

Emetics acting on the medullary centre :

(1) Apomorphine. (4) Senega.

(2) Tartar emetic. (5) Squill.

(3) Ipecacuanha.

Of these tartar emetic and ipecacuanha act partly on the stomach. The
first three are very powerful emetics, and are much more depressant in their
action than the gastric emetics.

Therapeutics. Emetics have two uses. Firstly, to remove
the contents of the stomach. Thus when that organ is over-full,
and there is a feeling of nausea, an emetic by emptying the
stomach may relieve. Emetics are largely used to empty the
stomach in cases of poisoning, and they may benefit certain
cases of sick headache. An emetic occasionally aids the expul-
sion of a foreign body which has become impacted in the fauces
or oesophagus. Secondly, emetics are used to expel the contents
of the air-passages, especially in children, for they cannot expec-
torate well. For this purpose these drugs are given to help chil-
dren to expel the morbid products in bronchitis, laryngitis, and



DRUGS ACTING ON THE DIGESTIVE APPARATUS.



8 9



diphtheria. They also aid the expulsion of foreign bodies that
have become impacted in the larynx. In choosing an emetic it
will be remembered that although apomorphine, ipecacuanha,
and tartar emetic are the most powerful they are the most
depressant, and are therefore not suitable in many cases such,
for instance, as poisoning accompanied by severe collapse. When
the poison is a powerful gastro -intestinal irritant, if the condi-
tion of the mouth and oesophagus will allow of it, it is preferable
to wash out the stomach rather than to use an emetic.

Emetics are not permissible for patients suffering from
aneurism, hernia, prolapse of uterus or rectum, peritonitis, or a
tendency to haemorrhage, because of the straining induced by
the vomiting, which should make us cautious in giving them to
those who have disease of their vessels or high tension in them,
for the straining may lead to haemorrhage.

9. Anti-emetics. The causes of vomiting are so numerous that
the number of drugs which may stop vomiting is very large ;
therefore, as in the case of emetics, we can only consider those
which act either on the stomach or on the centre in the medulla.

Anti-emetics acting on the stomach. These are all those sub-
stances which have been already enumerated as having a seda-
tive influence on the gastric nerves, viz. :



(1) Ice.

(2) Bismuth subcarbonate.

(3) Bismuth subnitrate.



(4) Opium.

(5) Hydrocyanic acid.

(6) Carbon dioxide.



Also some drugs which occasionally appear to have a specific local action
in arresting vomiting ; such are:



(i) Cocaine.
(2) Cerium oxalate. \j

(3) [Menthol.]

(4) Wine of ipecac.

(5) Tincture of iodine.

(6) Arsenous acid.



In

minute
doses.



(7) Alcohol.

(8) Carbolic acid.

(9) Chloroform.

(10) Creosote.

(11) Ether.

(12) Silver nitrate.

(13) The sulphocar-

bolates.



In
j- small
doses.



9O PHARMACOLOGY AND THERAPEUTICS.

Anti-emetics acting centrally



(1) Opium.

(2) Ammonium,

(3) Potassium, and

(4) Sodium bromides.



(6) Amyl nitrite.

(7) Nitroglycerin.

(8) Diluted hydrocyanic acid.

(9) Alcohol.



(5) Chloral hydrate.

It will be noticed that some drugs fall under both headings.

Therapeutics. The very name of these drugs indicates
their therapeutical application. At the best they are only pallia-
tive ; the right way to treat vomiting is, if possible, to remove
the cause. Of anti-emetics, ice, diluted hydrocyanic acid, car-
bon dioxide, bismuth salts, morphine, [menthol] and iodine are
perhaps the most reliable, but all are very uncertain.

D. Drugs acting on the intestines. Many secretions
are poured into the intestine, the food is much altered by the
time it arrives there, and it is changed in its course down the
intestine ; the physiology of intestinal digestion, of the move-
ments and the nervous mechanism of the intestine are imper-
fectly known ; drugs may be considerably altered by the time
they come to this part of the alimentary canal, and its diseases
are little understood ; consequently we cannot arrange the action
of drugs in a physiological classification. We know, in fact,
of only [three] important divisions : purgatives, [antiseptics]
and astringents.

The methods of experiments which have been used to deter-
mine the mode of action of purgatives are chiefly those of Thiry
and Moreau. The first-named observer cut the intestine across
in two places a short distance apart ; the isolated part which was
still attached to the mesentery was sewn up at one end ; the
other, the open end, was attached to the abdominal wall, and
thus there was a test-tube-like piece of intestine into which drugs
could be placed. The parts of intestine, on either side of the
excised piece, were sewn together, so that the whole intestine
was the same as before, but a little shorter. This method did
not give very satisfactory results, and consequently Moreau de-
vised his experiments, which seem more trustworthy. He put
four ligatures around the intestine at equal distances apart, so



DRUGS ACTING ON THE DIGESTIVE APPARATUS. 9 1

that he shut off from the rest of the [intestine] and from each
other three pieces of intestine, each of the same length. With
a fine syringe he injected into the middle piece the drug to be
experimented upon, and returned the whole into the abdominal
cavity. In a few hours the animal was -killed, and the state of the
interior of the middle piece was contrasted with that of the pieces
either side of it. Before Moreau's experiments there had been
much discussion as to whether some purgatives did not act only
by increasing the action of the muscular coat, and others only by
stimulating the secretions, but from these experiments it appears
that probably the majority act in both ways, some very slightly
on the secretion and powerfully on the muscle, and others
slightly on the muscle and powerfully on the secretion. We will



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