Encyclopedia of Health and Medicine

166 Drugs
requiring LIVER TRANSPLANTATION or KIDNEY TRANS-
PLANTATION.
Symptoms and Diagnostic Path
The symptoms of drug overdose vary according to
the drug or drugs involved and may range from
agitation to lethargy to loss of CONSCIOUSNESS.
Some symptoms are immediate, such as slowed
BREATHING and HEART RATE with narcotic overdose,
and others develop over time, such as JAUNDICE,
resulting from liver damage. Prompt medical treatment
is essential whenever there is cause to suspect
overdose. The kinds of symptoms a person
has can suggest the general nature of the toxicity
(narcotic, cholinergic, hepatotoxic) though it is
important to identify as quickly as possible what
drug or drugs the person has taken.
Treatment Options and Outlook
Treatment focuses on removing or neutralizing the
drug, when health-care providers are reasonably
certain what drug or drugs the person has taken.
Gastric lavage (“STOMACH pumping”) is the common
method for attempting to remove ingested
(swallowed) drugs. It is effective only within 30 to
60 minutes of ingestion; after this time any swallowed
substances have passed from the stomach
into the SMALL INTESTINE. Gastric lavage involves
inserting a nasogastric tube through the NOSE and
down the back of the THROAT into the stomach to
withdraw the stomach’s contents and flush the
stomach with liquid. Sometimes the doctor will
infuse a solution of activated charcoal, which is
highly absorbent, to help prevent more of the
drug from entering the BLOOD circulation. Doctors
do not agree about the effectiveness of gastric
lavage for improving the person’s risk for complications
of overdose, and gastric lavage itself carries
risks for esophageal perforation (damage to the
wall of the ESOPHAGUS) and aspiration of stomach
fluids into the LUNGS.
Antagonists, also called antidotes, are available
to reverse the effects of some kinds of drugs. They
include
• naloxone, which counteracts NARCOTICS
• N-acetylcysteine, which counteracts acetaminophen
• physostigmine, which counteracts some antihistamines
• flumazenil, which counteracts BENZODIAZEPINES
Other treatment targets symptoms and provides
supportive care until the body can metabolize
enough of the drug for blood concentrations to
drop below toxic levels. Such support might
include MECHANICAL VENTILATION when breathing is
impaired or dialysis for kidney failure. The extent
of permanent damage or the likelihood of death
depends on the drug and the amount as well as
how quickly the person receives treatment.
Risk Factors and Preventive Measures
Child-resistant containers and storing medications
in locked cabinets or drawers out of the reach of
children are important measures for preventing
accidental overdose in children. Adults should
store drugs in their original containers and check
the container before taking a dose of the drug.
Particularly with prescription drugs repackaged in
pharmacy containers, it is easy to grab the wrong
bottle and take one drug thinking it is another.
Contact the pharmacist or doctor if there are
unusual symptoms after taking any drug. It is also
crucial for the prescribing doctor and the dispensing
pharmacist to know all of the drugs a person is
taking, prescription and OTC (including MEDICINAL
HERBS AND BOTANICALS).
See also ADVERSE DRUG REACTION; AGING, EFFECTS
ON DRUG METABOLISM AND DRUG RESPONSE; ALCOHOL
INTERACTIONS WITH MEDICATIONS; CYTOCHROME P450
(CYP450) ENZYMES; HEPATOTOXINS; POISON PREVENTION.
over-the-counter (OTC) drug In the United
States, a DRUG that is available for purchase without
a prescription and that does not require a
pharmacist to dispense. However, US laws do
require OTC product labels to list the product’s
active ingredients, main inactive ingredients,
strength, recommended DOSAGE, significant side
effects (such as drowsiness), and any health conditions
a person might have in which the person
should not take the drug. Furthermore these
drugs must meet drug purity, consistency, and
safety standards. OTC drugs are available in a wide
variety of retail locations. Most OTC products