Pharmacology General Definitions

adverse effects

drugs effect, sometimes called side effects, that are not the desired therapeutic effects; may be unpleasant of even dangerous

brand name

name given to a drug by the pharmaceutical company that developed it; also called a trade name or proprietary name

chemical name

name that reflects the chemical structure of a drug

drugs

chemicals that are introduced into the body to bring about change

generic name

the original designation that a drug is given when the drug company that developed it applies for the approval process

off-label uses

uses of a drug that are not part of the stated therapeutic indications for which the drug was approved by the FDA; off-label uses may lead to new indications for a drug

orphan drugs

drugs that have been discovered but would not be profitable for a drug company to develop without outside financial incentives; usually drugs that would trat only a small number of people

Pharmacology

the study of the biological effects of chemicals

pharmacotherapeutic

clinical pharmacology - the branch of pharmacology that deals with drugs; chemicals that are used in medicine for the treatment, prevention, and diagnosis of disease in humans

Preclinical trials

initial trials of a chemical thought to have therapeutic potential either with in vitro or in vivo techniques; not human subjects

Teratogenic

having adverse effects on all phases of the development inside the womb (zygote, embryo, or fetus)

Absorption

what happens to a drug from the time it enters the body until it enters the circulating fluid

Chemotherapeutic agents

synthestic chemicals used to interfere with the functioning of foreign cell populations, causing cell death; this term is frequently used to refer to the drug therapy of neoplasms, but it also refers to drug therapy affecting any foreign cell

Critical concentration

the concentration a drug must reach in the tissue that respond to the particular drug to cause the desired therapeutic effect

distribution

movement of a drug to body tissues; the place where a drug may be distributed depends on the drug’s solubility, perfusion of the area, cardiac output, and binding of the drug to plasma proteins

Enzyme induction

process by which the presence of a chemical causes increased activity of an enzyme system

Excretion

removal of a drug from the body; routes include the kidney, skin, lungs, bile, and feces

First-pass effect

a phenomenon in which drugs given orally are carried directly to the liver after absorption, where they may be largely inactivated by liver enzymes before they can enter general circulation

glomerular filtration

the passage of water and water-soluble components from the plasma into the renal tubule

half-life

the time it takes for the amount of drug in the body to decrease to one half of the peak level it achieved

loading dose

a dose higher than what is usually used for treatment, administered to allow the drug to reach the critical concentration sooner

hepatic microsomal system

liver enzymes tightly packed together in the hepatic intracellular structure, responsible for the biotransformation of chemicals, including drugs

passive diffusion

movement of substances across a semipermeable membrane with the concentration gradient; this process does not require energy

Pharmacodynamics

the study of the interactions between the chemical components of living systems and the foreign chemicals, including drugs, that enter living organisms; the way a drug affects a body

pharmacogenomics

the study of genetically determined variations in the response to drugs

pharmacokinetics

the way a medication travels through the body, including absorption, distribution, biotransformation, and excretion; how the body acts on a drug

placebo effect

documented effect of the mind on drug therapy; if a person perceives that a drug will be effective, the drug is much more likely to be effective

receptor sites

specific areas on cell membranes that react with certain chemicals to cause an effect within the cell

selective toxicity

property of a chemotherapeutic agent that affects only systems found in foreign cells without affecting healthy human cells

Therapeutic index

ratio comparing the blood concentration at which a drug becomes toxic with the concentration at which the drug is effective

Blood dyscrasia

bone marrow suppression caused by drug effects on a rapidly multiplying cells of the bone marrow; lower-than-normal levels of blood components can be seen

dermatological reactions

skin reactions commonly seen as adverse effects of drugs; can range from simple rash to potentially fatal exfoliative dermatitis

poisoning

overdose of a drug that cases damage to multiple body systems and has the potential for fatal reactions

drug allergy or hypersensitivity

usually involves the formation of antibodies to a drug or drug protein; causes an immune response when the person is next exposed to that drug

stomatitis

inflammation of the mucous membranes related to drug effects; can lead to alteration in nutrition and dental problems

superinfections

infections causes by the destruction of normal flora bacteria by certain drugs, which allows other bacteria to grow out of control, and cause infection; may occur during antibiotic therapy

alternative therapy

includes herbs and other ‘natural’ products as often found in ancient records; since they are considered dietary supplements, these products are not controlled or tested by the U.S. food and drug administration in the same way that medications are controlled; however, they are sometimes the basis for discovery of an active ingredient that is later developed into an FDA-regulated medication

bactericidal

substances that cause the death of bacteria, usually by interfering with cell membranes stability or with proteins or enzymes necessary to maintains the cellular integrity of the bacteria

bacteriostatic

substances that prevent or slows the replications of bacteria, usually by interfering with proteins or enzymes systems necessary for reproductions of the bacteria

culture

sample of the bacteria to be grown in a laboratory to determine the species of bacteria causing a particular infection

prophylaxis

treatment to prevent an infection before it occurs or to prevent a second infection, as in the use of antibiotics to prevent bacterial endocarditis in high-risk patients or antiprotozoals to prevent malaria

Resistance

ability of pathogens over time to adapt to an anti-infective to produce cells that are no longer affected by a particular drug

sensitivity testing

evaluation of pathogens obtained in a culture to determine which anti-infective will be effective against the organisms causing a particular infection

spectrum

range of bacteria against which an antibiotic is effective

antibiotic

chemical that inhibits the growth of specific bacteria or causes the death of susceptible bacteria

synergistic

drugs that work together to increase drug effectiveness

acquired immunodeficiency syndrome (AIDS)

collection of opportunistic infections and cancers that occurs when the immune system is severely depressed by a decrease in the number of functioning helper T cells; caused by infection with human immunodeficiency virus (HIV)

AIDS-related complex (ARC)

collection of less serious opportunistic infection with HIV infection; the decreases in the number of helper T cells is less severe than is fully developed AIDS

CCR5 coreceptor antagonist

drug that blocks the receptor site on the T-cell membrane that the HIV virus needs to interact with in order to enter the cell

coronavirus

variety of types of RNA viruses that can cause several types of primary respiratory illnesses; one of the coronaviruses causes COVID-19

cytomegalovirus

DNA virus that accounts for many respiratory, ophthalmic, and liver infections

fusion inhibitor

a drug that prevents the fusion of the HIV-1 virus with the human cellular membrane, preventing it from entering the cell

helper T cell

human lymphocyte that helps to initiate immune reactions in response to tissue invasion

hepatitis B virus

virus that causes a serious to potentially fatal infection of the liver transmitted by body fluid (usually blood)

hepatitis C virus

virus that causes a usually mild infection of the liver that can progress to chronic inflammation with eventual need for liver transplant

herpes

DNA virus that accounts for many diseases, including varicella-zoster, cold sores, genital infections, and encephalitis

human immunodeficiency virus (HIV)

retrovirus that attacks helper T cells, leading to a decrease in immune function and AIDs and ARC

influenza A

RNA virus that invades tissues of the respiratory tract, causing the signs and symptoms of the common cold or ‘flu’

integrase strand transfer inhibitors

drug that inhibits the activity of the virus-specific enzyme integrase, an encoded enzyme needed for viral replication; blocking this enzyme prevents the formation of the HIV-1 provirus

interferon

tissue hormone that is released in response viral invasion; blocks viral replication

nonnucleoside reverse transcriptase inhibitors

drugs that bind to sites on the reverse transcriptase within the cell cytoplasm, preventing RNA- and DNA-dependent DNA polymerase activities needed to carry out viral DNA synthesis; prevents the transfer of information that allows the virus to replicate and survive.

nucleoside reverse transcriptase inhibitors

drugs that prevent the growth of the viral DNA chain, preventing it from inserting into the hot DNA, so viral replication cannot occur

protease inhibitors

drugs that block that activity of the enzyme protease in HIV; protease is essential for the maturation of infectious virus, and its absence leads to the formation of an immature and noninfective HIV particle

Virus

particle of DNA or RNA surrounded by a protein coat that survives by invading a cell to alter its functioning

azoles

a group of drugs used to treat fungal infections

candida

fungus that is normally found on mucous membranes; can cause yeast infections or thrush of the gastrointestinal (GI) tract and vagina in immunosuppressed patients; can cause serious systemic infection that can affect multiple organs in the body

ergosterol

steroid-type protein found in the cell membrane of fungi, similar in configuration to adrenal hormones and testosterone

fungus

a cellular organism with a hard cell wall that contains chitin and many polysaccharides, as well as a cell membrane that contains ergosterols

mycosis

disease caused by fungus

pneumocystis jirovecii pneumonia

opportunistic infection that occurs when the immune system is depressed; pneumocystis jirovecii is a common fungus that spreads through the air; a frequent cause of pneumonia in patients with AIDS and in those who are receiving immunosuppressive therpay

Tinea

fungus called ringworm that causes such infections as athlete’s foot, jock itch, and others

amebiasis

amebic dysentery, which is caused by intestinal invasion of the trophozoite state of the protozoan Entamoeba histolytica

Anopheles mosquito

type of mosquito that is essential to the life cycle of Plasmodium; injects the protozoa into humans for further maturation

cinchonism

syndrome of quinine toxicity characterized by nausea, vomiting, tinnitus, and vertigo

giardiasis

protozoal intestinal infection that causes severe diarrhea and epigastric distress; may lead to serious malnutrition

leishmaniasis

infection of the skin, mucous membrane, or viscera caused by a protozoan passed to humans by the bites of sand flies

malaria

protozoal infection with plasmodium, characterized by the cyclic fever and chills as the parasite is released from ruptured red blood cells; causes serious liver, central nervous system (CNS), heart, and lung damage

Plasmodium

a protozoan that causes malaria in humans; its life cycle includes the anopheles’ mosquito, which injects protozoa into humans

protozoa

single-celled organisms that pass through several stages in their life cycle, including at least one phase as a human parasite; found in areas with poor sanitation and hygiene and crowded living conditions

trichomoniasis

infestation with a protozoan that causes vaginitis in females but no signs or symptoms in males

trophozoite

a developing stage of a parasite, which uses the host for essential nutrients needed for growth

trypanosomiasis

African sleeping sickness, which is caused by a protozoan that inflames the CNS and is spread to humans by the bite of the tsetse fly; also, Chagas disease, which causes a serious cardiomyopathy after the bite of the housefly

Ascaris

parasitic worm that causes the most prevalent helminthic infection; ingested fertilized roundworm eggs hatch in the small intestine and then make their way to the lungs, where they may cause cough, fever, and other signs of a pulmonary infiltrate

cestode

tapeworm with a head and segmented body parts; capable of growing to several yards in the human intestine

filariasis

infection of the blood and tissues of healthy individuals by worm embryos or filariae

helminth

worm that can cause disease by invading the human body

hookworm

worm that attaches itself to the small intestine of an infected individual, where it sucks blood from the walls of the intestine, damaging the intestinal wall and leading to severe anemia with lethargy, weakness, and fatigue

nematode

a roundworm such as the commonly encountered pinworm, whipworm, threadworm, Ascaris, or hookworm; causes a common helminthic infection in humans; can cause intestinal obstruction as the adult worms clog the intestinal lumen or severe pneumonia when the larvae migrate to the lungs and form a pulmonary infiltrate

pinworm

nematode that causes a common helminthic infection in humans; lives in the intestine and causes anal and possible vaginal irritation and itching

platyhelminth

a flatworm, including the cestode and tapeworm; a worm that can live in the human intestine or can invade other human tissues (flukes)

schistosomiasis

infection with a blood fluke that is carried by a snail; it poses a common problem in tropical countries, where the snail is the intermediary in the life cycle of the worm; larvae burrow into the skin in fresh water and migrate throughout the human body, causing a rash, diarrhea, and liver and brain inflammation

threadworm

pervasive nematode that can send larvae into the lungs, liver, and central nervous system (CNS); can cause severe pneumonia or liver abscess

trichinosis

disease that results from ingestion of encysted roundworm larvae in undercooked pork; larvae migrate throughout the body to invade muscles, nerves, and other tissues; can cause pneumonia, heart failure, and encephalitis

whipworm

worm that attaches itself to the intestinal mucosa and sucks blood; may cause severe anemia and disintegration of the intestinal mucosa

alopecia

hair loss; a common adverse effect of many antineoplastic drugs, which are more effective against rapidly multiplying cells, such as those of hair follicles

anaplasia

a loss of cellular differentiation and organization, which leads to a loss of normal cellular function; a property of cancer cells

angiogenesis

the generation of new blood vessels; cancer cells release an enzyme that causes the growth of new blood vessels (angiogenesis) to feed the cancer cells

antineoplastic agent

drug used to combat cancer or the growth of neoplasms

autonomy

loss of the normal controls and reactions that inhibit growth and spreading; a property of cancer cells

bone marrow suppression

inhibition of the blood-forming components of the bone marrow; a common adverse effect of many antineoplastic drugs, which are more effective against rapidly multiplying cells, such as those in bone marrow; seen as anemia, thrombocytopenia, and leukopenia