Medical terms - Letter A (page 21) | MedicalVocabulary.org

Antibiotic

A drug used to treat infections caused by bacteria and other microorganisms. Originally, an antibiotic was a substance produced by one microorganism that selectively inhibits the growth of another. Synthetic…
Antibiotic resistance

Antibiotic resistance: The ability of bacteria and other microorganisms to withstand an antibiotic to which they were once sensitive (and were once stalled or killed outright). Also called drug resistance.
Antibiotic-resistant tuberculosis

See: Tuberculosis, antibiotic-resistant
Antibody

An immunoglobulin, a specialized immune protein, produced because of the introduction of an antigen into the body, and which possesses the remarkable ability to combine with the very antigen that triggered its…
Antibody cross reactivity

The ability of an antibody to react with similar antigenic sites on different proteins
Antibody, antinuclear

An unusual antibody that is directed against structures within the nucleus of the cell. Antinuclear antibodies (ANAs) are found in patients whose immune system is predisposed to cause inflammation against their own body…
Antibody, antithyroglobulin

An antibody directed against thyroglobulin which is a key protein in the thyroid gland essential to the production of thyroid hormones (thyroxine and triiodothyronine). Antithyroglobulin antibodies can damage the…
Antibody-dependent cell-mediated cytotoxicity

An immune response in which antibody, by coating target cells, makes them vulnerable to attack by immune cells. Antibody-dependent cell-mediated cytotoxicity is commonly (and blissfully) abbreviated ADCC.
Anticholinergic

The action of certain medications that inhibit the transmission of parasympathetic nerve impulses and thereby reduce spasms of smooth muscle (such as that, for example, in the bladder).
Anticipation

A remarkable phenomenon in which a genetic disease appears earlier appearance and with increased from with each succeeding generation. Anticipation was once thought not to exist in genetics. It was chalked off as a…
Anticipatory grief

The normal mourning that occurs when a patient or family is expecting a death. Anticipatory grief has many of the same symptoms as those experienced after a death has occurred. It includes all of the thinking, feeling…
Anticoagulant

Any agent used to prevent the formation of blood clots. Anticoagulants have various uses. Some are used for the prophylaxis (prevention) or the treatment of thromboembolic disorders. Thrombi are clots. Emboli are clots…
Anticoagulant agent

A medication used as a 'blood-thinner' to prevent the formation of blood clots and to maintain open blood vessels. Anticoagulants have various uses. Some are used for the prophylaxis (prevention) or the treatment of…
Anticonvulsant

A medication used to control (prevent) seizures (convulsions) or stop an ongoing series of seizures. There are a large number of anticonvulsant drugs today including, but not limited to: phenobarbital, phenytoin…
Antidepressant

>citalopram (Celexa, Cipramil) >escitalopram oxalate (Cipralex, Lexapro) >fluvoxamine maleate (Luvox) >paroxetine (Paxil, Seroxat, Aropax) >fluoxetine (Prozac) >sertraline (Zoloft, Lustral) The MAOIs or monoamine…
Antidepressant, MAOI

Monoamine oxidase inhibitor (MAOI), one of a potent class of medications used to treat depression
Antidepressant, SSRI

A selective serotonin reuptake inhibitor (SSRI), one of the commonly prescribed drugs for treating depression. SSRIs affect the chemicals that nerves in the brain use to send messages to one another. These chemical…
Antidepressant, tricyclic

One of a class of medications used to treat depression. The tricyclic antidepressants are also used for some forms of anxiety, fibromyalgia, and the control of chronic pain. 'Tricyclic' refers to the presence of three…
Antidiabetic agent

A substance that helps a person with diabetes control their level of glucose (sugar) in the blood. Antidiabetic agents include insulin and the oral hypoglycemic agents
Antidiuretic hormone (ADH)

A relatively small (peptide) molecule that is released by the pituitary gland at the base of the brain after being made nearby (in the hypothalamus). ADH has an antidiuretic action that prevents the production of dilute…
Antidote

An agent that counteracts a poison and neutralizes its effects. A chemical antidote is a substance that unites with a poison to form a harmless chemical compound. A mechanical antidote is a substance that prevents the…
Antielastase

An inhibitor of the action of the enzyme elastase. Alpha-1 antitrypsin is an antielastase. Also called an elastase inhibitor
Antiemetics

El ODYvAlign=top bgColor=#cccccc colSpan=2> vAlign=top width='100%' bgColor=#ffffff>Our Antiemetics Main Article provides a comprehensive look at the who, what, when and how of Antiemetics Antiemetics: 1. As a noun, a…
Antiestrogen

A substance that can prevent the full expression of estrogen. Antiestrogens act by exerting antagonistic effects on target tissues (androgens and progestogens act in this way) or by competing with estrogens for access…
Antifreeze poisoning

Poisoning from antifreeze which today is usually ethylene glycol -- a clear, colorless, odorless liquid with a sweet taste -- that can produce dramatic and dangerous toxicity. Ethylene glycol is found most commonly in…
Antifungal

A drug used to treat fungal infections. Examples of antifungal drugs include miconazole (MONISTAT) and clotrimazole (LOTRIMIN, MYCELEX).
Antifungal agent

A drug used to treat fungal infections. Examples of antifungal drugs include miconazole (MONISTAT) and clotrimazole (LOTRIMIN, MYCELEX).
Antifungal drug

A drug used to treat fungal infections. Examples of antifungal drugs include miconazole (MONISTAT) and clotrimazole (LOTRIMIN, MYCELEX).
Antifungal medication

A drug used to treat fungal infections. Examples of antifungal drugs include miconazole (MONISTAT) and clotrimazole (LOTRIMIN, MYCELEX).
Antigen

A substance that is capable of causing the production of an antibody. Antigens may or may not lead to an allergic reaction. Allergens are antigens that cause an allergic reaction and the production of IgE.
Antigen, prostate specific

See: PSA
Antigen-antibody complex

The complex formed by the binding of an antibody and an antigen. Antigen-antibody complexes are mediators of immune responses. Also known as an immune complex
Antigen-presenting cell

A cell that can 'present' antigen in a form that T cells can recognize it. The cells that can 'present' antigen include B cells and cells of the monocyte lineage (including macrophages)
Antigenic drift

A mechanism for variation by viruses that involves the accumulation of mutations within the antibody-binding sites so that the resulting viruses cannot be inhibited well by antibodies against previous strains making it…
Antigenic shift

A sudden shift in the antigenicity of a virus resulting from the recombination of the genomes of two viral strains. Antigenic shift is seen only with influenza A viruses. It results usually from the replacement of the…
Antihistamines

Drugs that combat the histamine released during an allergic reaction by blocking the action of the histamine on the tissue. Antihistamines do not stop the formation of histamine nor do they stop the conflict between the…
Antihypertensive

Something that reduces high blood pressure (hypertension)
Antiinfective

Something capable of acting against infection, by inhibiting the spread of an infectious agent or by killing the infectious agent outright. Anti-infective is a general term that encompasses antibacterials, antibiotics…
Antimalarial

A drug directed against malaria. The original antimalarial agent was quinine which took its name from the Peruvian Indian word 'kina' meaning 'bark of the tree.' A large and complex molecule, quinine is the most…
Antimetabolite

A drug that is similar enough to a natural chemical to participate in a normal biochemical reaction in cells but different enough to interfere with the normal division and functions of cells. So named because the drug…
Antimicrobial

A drug used to treat a microbial infection. 'Antimicrobial' is a general term that refers to a group of drugs that includes antibiotics, antifungals, antiprotozoals, and antivirals.
Antimicrobial agent

A general term for drugs, chemicals, or other substances that either kill or slow the growth of microbes. Among the antimicrobial agents are antibacterial drugs, antiviral agents, antifungal agents, and antiparisitic…
Antimicrobial drug

A drug used to treat a microbial infection. 'Antimicrobial' is a general term that refers to a group of drugs that includes antibiotics, antifungals, antiprotozoals, and antivirals.
Antimicrobial medication

A drug used to treat a microbial infection. The term 'antimicrobial' is a general one that refers to a group of drugs that includes antibiotics, antifungals, antiprotozoals, and antivirals.
Antimicrobial resistance

The result of microbes changing in ways that reduce or eliminate the effectiveness of drugs, chemicals, or other agents to cure or prevent infections
Antimony

A silvery-white earth metal which at high levels can be toxic. Antimony occurs naturally in the earth. Antimony ores are mined and then mixed with other metals to form antimony alloys or combined with oxygen to form…
Antineoplastic

Acting to prevent, inhibit or halt the development of a neoplasm (a tumor). An agent with antineoplastic properties. For example, oxaliplatin (Eloxatin) is an antineoplastic used in the treatment of metastatic colon…
Antinuclear antibody

Antinuclear antibody: An unusual antibody that is directed against structures within the nucleus of the cell. Antinuclear antibodies (ANAs) are found in patients whose immune system is predisposed to cause inflammation…
Antinuclear antibody test

Antinuclear antibody test: A test for unusual antibodies that are directed against structures within the nucleus of the cell. Antinuclear antibodies (ANAs) indicate the possible presence of autoimmunity. The fluorescent…
Antioxidant

Any substance that reduces oxidative damage (damage due to oxygen) such as that caused by free radicals. Free radicals are highly reactive chemicals that attack molecules by capturing electrons and thus modifying…