Chemical name
A drug name that is derived from the specific chemical structure of the compound. Chemical names are not used clinically but are shortened in some way to form the drug's generic name.
Controlled substances
Drugs designated by the federal government as having increased potential for abuse and illegal use. These substances are grouped into five categories (schedules), with schedule I substances having the highest abuse potential and schedule V substances havi
Dose-response curve
The relationship between incremental doses of a drug and the magnitude of the reaction that those doses will cause.
Median effective dose (ED50):
The drug dose that produces a specific therapeutic response in 50 percent of the patients in whom it is tested.
Median lethal dose (LD50)
The drug dose that causes death in 50 percent of the experimental animals in which it is tested.
Median toxic dose (TD50)
The drug dose that produces a specific adverse (toxic) response in 50 percent of the patients in whom it is tested.
Nonproprietary name
A drug name that is usually a shortened version of the drug's chemical name and is recognized as the standard name for that drug regardless of the drug's trade or brand names (SYN: generic name).
Off-label prescribing
A drug is prescribed to treat conditions other than those approved by the FDA.
Orphan drugs
Drugs that are designed and approved to treat rare diseases. Because these drugs are only used in a small patient population (usually less than 200,000 people), financial and other incentives are often provided by various sources to encourage a drug compa
Over-the-counter drugs (OTC)
Drugs that can be purchased directly by the consumer without a prescription (SYN: nonprescription drugs).
Pharmacodynamics
what the drug does to the body - The study of how drugs affect the body�that is, the physiological and biochemical mechanisms of drug action.
Pharmacogenetics
The study of the how genetic variability can influence drug responses and metabolism.
Pharmacokinetics
what the body does to the drug- The study of how the body handles drugs�that is, the manner in which drugs are absorbed, distributed, metabolized, and excreted.
Pharmacotherapeutics
The study of how drugs are used in the prevention and treatment of disease.
Pharmacy
The professional discipline dealing with the preparation and dispensing of medications.
Potency
The dose of a drug that produces a given response in a specific amplitude. When two drugs are compared, the more potent drug will produce a given response at a lower dose.
Therapeutic index (TI)
ratio of LD50 to ED50 - A ratio used to represent the relative safety of a particular drug; the larger the therapeutic index, the safer the drug. It is calculated as the median toxic dose divided by the median effective dose. (In animal trials, the median
Toxicology
The study of the harmful effects of drugs and other chemicals.
Trade name
The name given to a drug by the pharmaceutical company; it is protected by a trademark and used by the company for marketing the drug (SYN: brand name or proprietary name).
Bioavailability
The extent to which a drug reaches the systemic circulation following administration by various routes.
Buccal
Referring to the cheek. Drugs administered buccally are placed between the cheek and gum and are absorbed into the circulation from the mucosa lining the gums and inner cheek.
Enteral administration
Administration of drugs by way of the alimentary canal.
First-pass effect
The phenomenon in which drugs absorbed from the stomach and small intestine must pass through the liver before reaching the systemic circulation. Certain drugs undergo extensive hepatic metabolism because of this first pass through the liver.
Intrathecal
Administration of substances within a sheath; typically refers to injection into the sub-arachnoid space surrounding the spinal cord.
Parenteral administration
Administration of drugs by routes other than via the alimentary canal: by injection, transdermal, topical, and so on.
Proton pump
An enzyme that moves hydrogen ions (protons) across the cell membrane. The gastric proton pump transports hydrogen ions into the stomach; drugs that inhibit this enzyme are known as proton pump inhibitors, and these drugs are used to reduce the formation
Sublingual
Under the tongue; drugs administered sublingually are absorbed into the systemic circulation via the venous drainage from underneath the tongue.
Volume of distribution (Vd)
A ratio used to estimate the distribution of a drug within the body relative to the total amount of fluid in the body. It is calculated as the amount of drug administered divided by the plasma concentration of the drug.
Biotransformation
Biochemical changes that occur to the drug within the body, usually resulting in the breakdown and inactivation of the drug (SYN: drug metabolism).
Clearance
The process by which the active form of the drug is removed from the bloodstream by either metabolism or excretion.
Drug microsomal metabolizing system (DMMS)
A series of enzymes located on the smooth endo-plasmic reticulum that are important in catalyzing drug biotransformation.
Half-life
The time required to eliminate 50 percent of the drug existing in the body.
Metabolite
The compound that is formed when the drug undergoes biotransformation and is chemically altered by some metabolic process.
Adenylate cyclase
An enzyme located on the inner surface of many cell membranes; it is important in mediating biochemical changes in the cell in response to drug and hormone stimulation (SYN: adenyl cyclase).
Affinity
The mutual attraction between a drug and a specific cellular receptor.
Agonist
A drug that binds to a receptor and causes some change in cell function (ANT: antagonist).
Allosteric modulators
Substances that bind to a cell receptor and alter the receptor's affinity for specific drugs; common allosteric modulators include guanine nucleotides, ammonium ions, calcium, and other divalent cations.
Antagonist
A drug that binds to a receptor but does not cause a change in cell activity (SYN: blocker).
Cyclic adenosine monophosphate (cAMP)
The ring-shaped conformation of adenosine monophosphate, which is important in acting as a second messenger in mediating the intracellular response to drug stimulation.
Desensitization
A brief and transient decrease in the responsiveness of cellular receptors to drug effects.
Down-regulation
A prolonged decrease in the number and/or sensitivity of drug receptors, usually occurring as a compensatory response to overstimulation of the receptor.
Gamma-aminobutyric acid (GABA)
An inhibitory neurotransmitter in the brain and spinal cord.
G proteins
Proteins that bind with guanine nucleotides and regulate cell activity. G proteins often serve as a link between surface receptors and ion channels or intracellular enzymes such as adenylate cyclase
Second messenger
The term applied to compounds formed within the cell, such as cyclic AMP. The second messenger initiates a series of biochemical changes within the cell following stimulation of a receptor on the cell's outer surface by drugs, hormones, and so on.
Selective estrogen receptor modulator (SERM)
A drug that activates estrogen receptors on bone and vascular tissues, while blocking estrogen receptors on breast and uterine tissues. These drugs can be used to enhance bone mineralization and to prevent certain cancers.
Acetylcholine
A neurotransmitter in the somatic and autonomic nervous systems; principal synapses using acetylcholine include the skeletal neuromuscular junction, autonomic ganglia, and certain pathways in the brain.
Adrenergic
Refers to synapses or physiological responses involving epinephrine and norepinephrine.
Beta-receptor
A primary class of the receptors that are responsive to epinephrine and (to a lesser extent) norepinephrine. Beta receptors are subclassified into beta-1 and beta-2 receptors based on their sensitivity to various drugs.
Cholinergic
Refers to synapses or physiological responses involving acetylcholine.
Norepinephrine
A neurotransmitter that is important in certain brain pathways and in the terminal synapses of the sympathetic nervous system (SYN: noradrenaline).
Sympathetic
The sympathetic nervous system is one of the two main divisions of the autonomic nervous system - Fight or Flight -Thoracolumbar (T1-L3)- Adrenergic-
Parasympathetic
The parasympathetic nervous system is one of the two main divisions of the autonomic nervous system - Craniosacral - rest & Digest - Cholinergic - Nicotinic and Muscarinic
Alpha-Receptor
A primary class of the receptors that are responsive to epinephrine and (to a lesser extent) norepinephrine. Alpha receptors are subclassified into alpha-1 and alpha-2 receptors based on their sensitivity to various drugs.
Anticholinergics
Drugs that decrease activity at acetylcholine synapses. These agents are often used to diminish activity in the parasympathetic nervous system (SYN: parasympatholytic).
Parkinson disease or Parkinsonism
The clinical syndrome of bradykinesia, rigidity, resting tremor, and postural instability associated with neurotransmitter abnormalities within the basal ganglia.
Aldosterone
A steroid (mineralocorticoid) hormone produced by the adrenal cortex that acts on the kidney to increase sodium reabsorption, thereby retaining sodium in the body.
Angiogenesis
The development of new blood vessels. Drugs that inhibit this effect can be useful in limiting the growth and proliferation of certain tumors.
Hyperlipidemia
Involves abnormally elevated levels of any or all lipids and/or lipoproteins in the blood. It is the most common form of dyslipidemia (which includes any abnormal lipid levels).
Hypertension
A pathological condition characterized by a sustained, reproducible increase in blood pressure.
Metabolic syndrome
A condition characterized by insulin resistance, high blood pressure, abdominal obesity, and hyperlipidemia (SYN: Syndrome X).
Orthostatic hypotension:
A sudden fall in blood pressure that occurs when the patient stands erect; this is a frequent side effect of many medications.
Sympatholytics
Drugs that inhibit or antagonize function within the sympathetic nervous system.
Angina pectoris
Severe pain and constriction in the chest region, usually associated with myocardial ischemia.
Anticoagulation
A decrease in the blood's capacity to coagulate (clot). Drugs with the ability to decrease coagulation are known as anticoagulants.
Arrhythmia
A significant deviation from normal cardiac rhythm that results in a heart rate that is slower or faster than normal, or irregular (SYN: dysrhythmia).
Congestive heart failure
A clinical syndrome of cardiac disease that is marked by decreased myocardial contractility, peripheral edema, shortness of breath, and decreased tolerance for physical exertion.
Dopamine
A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.The presence of endogenous or exogenous dopamine in the periphery also affects cardiovascular function.
Inotropic
Refers to a substance that increases muscular contraction force (positive inotrope) or decreases contraction force (negative inotrope). Certain cardiac drugs are considered positive inotropes because they increase the force of cardiac contractions.
Pharmacotherapeutics
The study of how drugs are used in the prevention and treatment of disease.
Phosphodiesterase (PDE)
An enzyme that breaks down phosphodiester bonds in organic compounds. Certain phosphodiesterases are important clinically because they break down second messengers such as cyclic AMP, and drugs that inhibit these enzymes prolong the effects of cyclic AMP
Fibrinolytics
Drugs which facilitate the breakdown and dissolution of clots that have already formed. These drugs work by converting plasminogen (profibrinolysin) to plasmin (fibrinolysin). Streptokinase, tenecteplase (TNKase)
Hemophilia
A hereditary disease in which an individual is unable to synthesize adequate amounts of a specific clotting factor.
Hemostasis
The process of preventing blood loss from the circulation following injury to blood vessels (ANT: hemorrhage).
Thrombus
A blood clot formed by the activation of fibrin and platelets. Excessive thrombus formation (thrombosis) can be controlled by drugs that affect various aspects of the clotting mechanisms.
Generic name
The name applied to a drug, which is not protected by a trademark; usually a shortened version of the drug's chemical name (SYN: nonproprietary name).