EMETICS—INDUCING VOMITING
When a patient ingests a toxic substance, it is critical that the toxin be expelled
or neutralized before the body can absorb it. However, vomiting should not be
induced if the toxin is a caustic substance such as ammonia, chlorine bleach,
lye, toilet cleaners, or battery acid. Regurgitating these substances can cause
additional injury to the esophagus. Vomiting should also be avoided if petro-
leum distillates are ingested. These include gasoline, kerosene, paint thinners,
and lighter fluid.
In cases where vomiting is contraindicated, the patient should be adminis-
tered activated charcoal, which is available in tablets, capsules, or suspension.
Charcoal absorbs (detoxifies) ingested toxic substances, irritants, and intestinal
gas. Activated charcoal can be given as a slurry (30 grams in at least 8 oz. of
water) or 12.5–50 grams in aqueous or sorbitol suspension. It is usually given as
a single dose.
In cases where vomiting is desired, use one of two ways to expel a toxin:
The nonpharmacological treatment is to induce vomiting by stimulating the
gag reflex by placing a finger or a toothbrush in the back of the patient’s throat.
Pharmacological treatment involves administering an emetic to induce vomit-
ing. Ipecac is the most commonly used emetic. Ipecac, available over the counter,
should be purchased as a syrup—not a fluid extract. The syrup induces vomiting
by stimulating the CTZ in the medulla and acts directly on the gastric mucosa.
Ipecac should be taken with at least eight or more ounces of water or juice (do
not use milk or carbonated beverages). If vomiting does not occur within 20 min-
utes, then the dose should be repeated. If vomiting cannot be induced, then
administer activated charcoal. The absorption of ipecac is minimal. Protein-bind-
ing is unknown and the half life is short. Duration of action is only 20–25 min-
utes. Do not attempt to induce vomiting if the patient is not fully awake and alert.
ANTI-DIARRHEA
Diarrhea is defined as frequent liquid stools that can be caused by foods, fecal
impaction, bacteria (Escherichia coli, Salmonella), virus (parvovirus, rotavirus),
toxins, drug reaction, laxative abuse, malabsorption syndrome caused by lack of
digestive enzymes, stress and anxiety, bowel tumor, and inflammatory bowel
disease such as ulcerative colitis or Crohn’s disease.
Diarrhea can be mild (lasting one bowel movement) or severe (lasting several
bowel movements). Intestinal fluids are rich in water, sodium, potassium, and
bicarbonate, and diarrhea can cause minor or severe dehydration and electrolyte
imbalances. The loss of bicarbonate places the patient at risk for developing
CHAPTER 18 Gastrointestinal System^335