Intro Flashcards
sources of drugs
plants
animals
inorganic
synthetic
chemical name of drugs
describes a drugs chemical composition and molecular structure
generic name of drugs
the original designation that the drug is given when the drug company applies for approval of the drug
trade/brand name
the name given by the drug company who developed it once the drug is approved for use
classification of drugs
therapeutic and pharmacological
therapeutic classification
describes what is being treated by the drug
pharmacological classification
describes how the drug acts
bioavailability
is the rate and extent to which the active ingredients is absorbed from a drug product and becomes available at the site of drug action to produce an effect
dissolution
identify the rate in which drugs are absorbed by the body with number one having the fastest absorption rate and number six the slowest absorption rate
pharmacokinetics
study of what the body does to the drug
pharmacodynamics
study of what the drug does to the body and the drugs mechanism of action
pharmacotherapeutics
putting pharmaceutics, pharmacokinetics, and pharmacodynamics into clinical practice
pharmacokinetics
absorption -> distribution -> metabolism -> excretion
absorption
rate at which the drug enters the body until it enters the bloodstream
what routes bypass absorption and why
intravenous and intra-arterial because the drugs are placed directly into the bloodstream
factors that affect absorption
blood flow in the stomach/intestines ph in the stomach surface area of the small intestine (villi) health of the small intestine (crohn's disease) food or fluid in the intestines bowel resection age infection or exercise form of drug - composition (liquid)
routes of administration
enteral sublingual (SL)/buccal topical parenteral subcutaneous (SC) intramuscular (IM) intravenous (IV)
enteral route
drugs are delivered to the gastrointestinal tract either by the oral route or by nasogastric or gastrostomy tubes
often the route that is intended for general circulation (a few drugs given orally are site specific for the GI tract)
enteral route - tablets and capsules
the dissolution of the capsule or tablet is the slowest part of absorption enteric coating (EC) protects the tablet fro the stomach acid. Designed to dissolve in an alkaline environment. Prevent irritation of stomach mucosa XR (extended release, SR (sustained release), LA (long acting) are designed to dissolve very slowly
sublingual/buccal route
enteral routes but the medication is not swallowed, instead kept in mouth
sublingual is under the tongue
buccal is between the gum and cheek
mucosa of the mouth has extensive capillaries that provides an excellent absorptive surface
topical
medications applied to the skin or mucous membranes
skin is most common
mucosal application includes ears, eyes, nose, respiratory tract, vagina, rectum
most are administered to have a local effect (topical antibiotics) but there are some that are administered fr a systemic effect (nitroglycerin)
transdermal patches avoid first pass effect and bypass digestive enzymes
absorb very slowly because the skin’s keratin layer must be penetrated
parenteral
by injection (ID, SC, IM) or intravenous the drug is delivered into the skin layers (intradermal ID), subcutaneous tissue (subcutaneous SC), muscles (intramuscular IM), veins (intravenous IV) less common routes include intra-arterial, bone (intraosseous), body cavities (intrathecal), organs (intra-cardiac) bypass the liver therfore bypass first pass effect fastest but potentially the most harmful more invasive
subcutaneous or intramuscular route
muscles have greater blood supply than fatty tissues
absorption increases with massage, heat, activity = causes vasodilation
absorption decreases with cold = vasoconstriction
intravenous route
most common parenteral route
fastest onset but most dangerous
rapid effect with maximum degree of control over the amount of drug delivered
bolus = full amount of the drug is delivered to systemic circulation immediately
intermittent = infused over a longer period of time with lower peak plasma concentrations and increased circulating duration
large volume infusion = fluid maintenance, supplementation, or replacement (potassium)
distribution
transporting of the drug into body by blood stream into circulation
some sites distribute the drug differently: bones, blood brain barrier
metabolism
transformation of a drug into an inactive substance
once the drug enters the body the process of elimination begins (hepatic, urinary, and biliary)
excretion
elimination of drugs from the body
half life
the length of time it takes for the drugs concentration to decrease by one half
terminology = onset
the time to elicit therapeutic response
terminology = duration of action
length of time drug is sufficient to elicit therapeutic response
terminology = peak
maximum therapeutic response
terminology = trough
the lowest level of drug in the body
terminology = loading dose
a large initial dose
factors influencing drug effects
weight muscle content ph balance hydration diseases genetic allergies placebo effect environment tolerance successive doses/double dosing two or more drugs taken at same time and interacting food
pharmacodynamics
the relationship between the drug and the physiological response
receptor interaction
joining of drug molecule with reactive sites along the cell or tissue
agonist vs. antagonist
enzyme interaction
drugs can inhibit the action of a specific enzyme to reach therapeutic effects
drugs fool the enzyme, bind to it to prevent the action of the enzyme
drug reactions
side effects = undesirable effect to a medication that is expected
adverse effects = more serious than side effects
allergic reactions = an immunologic hypersensitivity reaction
unintentional adverse effects that are treatment induced
dermatologic nephrotoxic - renal damage blood dyscrasia hepatotoxic - liver toxicity neurotoxic - neural toxicity cardio toxic skeletal muscle toxicity bone marrow toxicity
drug related effects
teratogenic - structural defects in the unborn fetus
mutagenic - permanent changes in genetic composition of living organisms chromosomes and DNA, carcinogenic, exogenous factors
toxicology
the study of poisons and unwanted responses to therapeutic agents
poison control centers are equipped with information needed for the treatment of poisoned patients or overdoses
drug approval process
scientific testing to ensure drugs are safe before marketing
phases of drug development - pre-clinical research
chemicals that may have therapeutic value are tested extensively in the laboratory on human and microbial cells cultured in the laboratory and eventually on animals to see how the drug acts and predict potential harm to humans
phases of drug development - phase 1
conducted on 20-80 healthy human volunteers for several months to test drugs and assess adverse effects
focus is safety
phases of drug development - phase 2
drug is tested on several hundred patients with the disease that the drug is meant to treat
phases of drug development - phase 3
using the drug in a vast clinical market (large number of patients with the disease)
looks at patient variability and drug interactions
canadian drug legislation purposes
to protect the consumer from drugs that are contaminated, adulterated, or unsafe for use
to address drugs that are labeled falsely or labeling that may be misleading and or deceptive
drug schedules
prescription drug list: all prescription
schedule G: control drugs; potential for abuse
schedule C: radiopharmaceutical drugs
schedule D: biological products
Narcotics: (narcotic control act)
OTC: over the counter medications do not appear on any schedule
drug misuse
use of a drug for purposes other than those for which it is inteneded
drug abuse
dependence on a substance that has negative impact on the body
tolerance
decreased effect of a substance that results from repeated exposure
addiction
uncontrollable dependence on a substance that cessation causes severe emotional, mental, or physiologic reactions
cautions with use of over the counter medications
delay in professional diagnosis and treatment
symptoms may be masked
inactive ingredients may cause adverse reactions
potential for overdose
drug interactions
forms of herbs
dried herbs
fresh herbs
oils = made by soaking dried dried herbs in oil then heating for extended time
salves = semisolid fatty preparations, made by melting a wax in oil and allowing it to cool and harden
tinctures = made by soaking fresh or dried herbs in a solvent (water or alcohol)
teas = steeping herbs in water can be drank, put in a bath, or applied topically as a compress
extracts = made by isolating certain components resulting in a more reliable dose
syrups = usually made by adding a sweetener, usually honey or sugar, to the herb and then cooking it
forms of herbs
dried herbs
fresh herbs
oils = made by soaking dried dried herbs in oil then heating for extended time
salves = semisolid fatty preparations, made by melting a wax in oil and allowing it to cool and harden
tinctures = made by soaking fresh or dried herbs in a solvent (water or alcohol)
teas = steeping herbs in water can be drank, put in a bath, or applied topically as a compress
extracts = made by isolating certain components resulting in a more reliable dose
syrups = usually made by adding a sweetener, usually honey or sugar, to the herb and then cooking it
required labels
scientific names; part of plant used
manufacturer’s name and address
batch and lot number
date of manufacture and expiration
