Unit 1-5 Flashcards
Receptors
Usually the drug forms chemical bonds with specific sites
Pharmacodynamics
The study of the interactions between drugs and their receptors and the series of events that result in a pharmacologic response
Agonists
Drugs that interact with a receptor to stimulate a response
Antagonists
Drugs that attach to a receptor but do not stimulate a response
Partial Agonists
Drugs that interact with a receptor to stimulate a response but inhibit other responses
Enteral Route
Drug is administered directly into the gastrointestinal (GI) tract by the oral, rectal, or nasogastric route.
Parenteral Route
Bypasses the GI tract with the use of subcutaneous (subcut), intramuscular (IM), or intravenous (IV) injection.
Percutaneous Route
Involves drugs being absorbed through the skin and mucous membranes.
*Methods of the percutaneous route include inhalation, sublingual (under the tongue), and topical (on the skin) administration.
Pharmacokinetics
The study of the mathematical relationships among the ADME features of individual medicines over time
LADME
Liberation, Absorption, Distribution, Metabolism, and Excretion
Absorption
Process whereby a drug is transferred from its site of entry into the body to the circulating fluids of the body (i.e., blood and lymph) for distribution around the body
Distribution
Refers to the ways in which a drug is transported throughout the body by the circulating body fluids to the sites of action or to the receptors that the drug affect
Drug Distribution
Refers to the transport of the drug throughout the entire body by the blood and lymphatic systems and the transport from the circulating fluids into and out of the fluids that bathe the receptor site
Unbound
Free; portion of a drug is able to diffuse into tissues, interact with receptors, and produce physiologic effects; it is also only this portion that can be metabolized and excreted
Drug blood level
When a drug is circulating in the blood, a blood sample may be drawn and assayed to determine the amount of drug present
Metabolism
Process whereby the body inactivates drugs. The enzyme systems of the liver are the primary sites for the metabolism of drug
Excretion
The elimination of drug metabolites and, in some cases, of the active drug itself from the body
Half-life
Amount of time required for 50% of the drug to be eliminated from the body
Onsite of Action
When the concentration of a drug at the site of action is sufficient to start a physiologic (pharmacologic) response
Peak Action
Drug reaches the highest concentrations on the target receptor sites, thereby inducing the maximal pharmacologic response for the dose given
Duration of Action
How long the drug has a pharmacologic effect
Desired Action
Expected response
Side effects/adverse effects
all drugs have the potential to affect more than one body system simultaneously, thereby producing responses
Serious Adverse Effects
Can lead to toxicity
Idiosyncratic Reaction
when something unusual or abnormal happens when a drug is first administere
Allergic Reactions
also known as hypersensitivity reactions, occur in about 6% to 10% of patients who are taking medications. Allergic reactions occur among patients who have previously been exposed to a drug and whose immune systems have developed antibodies to the drug
Urticaria
Severe itching
Hives
Irregular shaped patches on the skin
Anaphylactic Reaction
Patient has a severe, life-threatening reaction that causes respiratory distress and cardiovascular collapse
Enzyme Inducers
Common drugs that bind to enzymes and increase the metabolism of other drugs
*phenobarbital, carbamazepine, rifampin, and phenytoin
Additive effect
Two drugs with similar actions are taken for an increased effect.
*hydrocodone + acetaminophen = added analgesic effect
Synergistic effect
The combined effect of two drugs is greater than the sum of the effect of each drug given together
ex: aspirin + codeine = much greater analgesic effect
Antagonistic effect
One drug interferes with the action of another.
ex: tetracycline + antacid = decreased absorption of the tetracycline
Displacement
The displacement of the first drug from protein-binding sites (i.e., bound drugs are inactive) by a second drug increases the activity of the first drug because more unbound drug is available.
ex: warfarin + valproic acid = increased anticoagulant effect
Interference
The first drug inhibits the metabolism or excretion of the second drug, thereby causing increased activity of the second drug.
ex: probenecid + ampicillin = prolonged antibacterial activity of ampicillin because probenecid blocks the renal excretion of ampicillin
Incompatibility
The first drug is chemically incompatible with the second drug, thereby causing deterioration when the drugs are mixed in the same syringe or solution or are administered together at the same site. Signs include haziness, formation of a precipitate, or a change in the color of the solution when the drugs are mixed
Pharmacology
study of drugs and their actions on living organisms.
Therapeutic methods
Drug Therapy
Diet Therapy
Physiotherapy
Psychological Therapy
Therapies
Diseases that cause illness may be treated in several different ways