In
medicine
Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...
, a contraindication is a condition (a situation or factor) that serves as a reason not to take a certain medical treatment due to the harm that it would cause the patient. Contraindication is the opposite of
indication, which is a reason to use a certain treatment.
Absolute contraindications are contraindications for which there are no reasonable circumstances for undertaking a course of action (that is, overriding the prohibition). For example:
* Children and teenagers with viral infections should not be given
aspirin
Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...
because of the risk of
Reye syndrome.
* A person with an
anaphylactic food allergy
A food allergy is an abnormal immune system, immune response to food. The symptoms of the allergic reaction may range from mild to severe. They may include pruritus, itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathi ...
should never eat the food to which they are allergic.
* A person with
hemochromatosis should not be administered iron preparations.
* Some medications are so
teratogenic that they are absolutely contraindicated in pregnancy; examples include
thalidomide
Thalidomide, sold under the brand names Contergan and Thalomid among others, is an oral administered medication used to treat a number of cancers (e.g., multiple myeloma), graft-versus-host disease, and many skin disorders (e.g., complication ...
and
isotretinoin
Isotretinoin, also known as 13-''cis''-retinoic acid and sold under the brand name Accutane among others, is a medication used to treat skin diseases like harlequin-type ichthyosis, and lamellar ichthyosis, and severe cystic acne or moderat ...
.
Relative contraindications are contraindications for circumstances in which the patient is at higher risk of complications from treatment, but these risks may be outweighed by other considerations or mitigated by other measures. For example, pregnant individuals should normally avoid getting
X-ray
An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...
s, but the risk from
radiography
Radiography is an imaging technology, imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical ("diagnostic" radiog ...
may be outweighed by the benefit of diagnosing (and then treating) a serious condition such as
tuberculosis
Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...
.
Another principal pair of
terms for ''relative contraindications'' versus ''absolute contraindications'' is ''cautions'' versus ''contraindications'', or (similarly) ''precautions'' versus ''contraindications'': these pairs of terms are respectively synonymous. Which pair is used depends on
nomenclature
Nomenclature (, ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. (The theoretical field studying nomenclature is sometimes referred to as ''onymology'' or ''taxonymy'' ). The principl ...
enforced by each organization's
style
Style, or styles may refer to:
Film and television
* ''Style'' (2001 film), a Hindi film starring Sharman Joshi, Riya Sen, Sahil Khan and Shilpi Mudgal
* ''Style'' (2002 film), a Tamil drama film
* ''Style'' (2004 film), a Burmese film
* '' ...
. For example, the ''
British National Formulary'' uses the ''cautions versus contraindications'' pair, and various U.S.
CDC webpages use ''precautions'' versus ''contraindications''. The logic of the latter two styles is the idea that readers must never be confused: the word ''contraindication'' in that
usage ''always'' is meant in its absolute
sense
A sense is a biological system used by an organism for sensation, the process of gathering information about the surroundings through the detection of Stimulus (physiology), stimuli. Although, in some cultures, five human senses were traditio ...
, providing unmistakable
word-sense disambiguation.
See also
* ''
Classification of Pharmaco-Therapeutic Referrals''
*
Drug reaction testing
*
Indication (medicine)
In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. There can be multiple indications to use a procedure or medication. An indication can commonly be confused with the term diagnosis. A diagnosis ...
*
Never events
References
{{wiktionary
Medical terminology