HLTH 2501 module 4: pharmacology Flashcards
what is pharmacology?
the study of drugs, their actions, dosage, therapeutic uses, and adverse effects
what is a drug?
a substance that alters biologic activity in a person
what may drugs come from?
plants, animals, microorganisms such as fungi, or they may be synthesized
reasons why drugs may be prescribed?
to promote healing, to cure a disease, to slow a disease, to prevent a disease, to increase comfort, as replacement therapy, and to reduce excessive activity in the body
pharmcodynamics
drug-induced responses of physiologic and biochemical systems
pharmacokinetics
drug amounts at different sites after administration
pharmacotherapeutics
choice and drug application for disease prevention, treatment, or diagnosis
toxicology
study of the body’s response to drugs, harmful effects, mechanisms of action, symptoms, treatment, and identification
pharmacy
preparation, compounding, dispensing, and record keeping of therapeutic drugs
separate disciplines of pharmacology
pharmacodynamics, pharmacokinetics, pharmacotherapeutics, toxicology, and pharmacy
what are drugs classified on?
their primary pharmacologic action and effect; ex. anti inflammatory
indications for drugs
found in a drug manual and provide the approved uses of diseases for which the drug has been effective
side effects
are unwanted actions of a drug and are often mild, ex. dry mouth
adverse effects
toxic side effects that are dangerous, cause tissue damage, or are life-threatening; ex. excessive bleeding
types of adverse effects
hypersensitivity responses, idiosyncratic, iatrogenic, teratogenic, and interactions
idiosyncratic response
reactions are unexpected and unusual; ex. excessive excitement after taking a sedative
iatrogenic response
refers to a negative effect on the body caused by a medication error, drug overdose, or unusual response
teratogenic effects
effects that are harmful on the fetus, leading to developmental defects
interaction reactions
occur when a drug’s effect is modified by combining it with another drug, food, herbal compound, or other material; occur often with nonprescription drugs
synergism
interaction effect causing an increased reaction; can be life-threatening such as coma or a hemorrhage
antagonism
interaction effect causing a decreased reaction
potentiation
when one drug enhances the effect of a second drug
dose vs dosage
dose is the amount of drug given as a single time and dosage is the total amount of the drug given over a period of time
loading dose principle
refers to the first dose being larger or given by injection to achieve effective drug levels effectively
why is the frequency of drug dosing important?
because it maintains effective blood levels of the drug without toxicity
what are optimal dosing schedules based on?
absorption rate, how it is transported in the blood, half-life of the drug, and biotransformation
most common drug schedule
taken every 6 hours over the 24-hour day, often with meals
what are blood levels of a drug dependent on?
circulation, age, gender, body weight and BMI, activity level, food and fluid intake, ability to absorb and metabolize drugs, genetic factors, and presence of diseases
local administration of drugs
includes topical application to the skin or mucous membranes, oral administration, or some inhalation drugs
systemic administration of drugs
includes transdermal, oral, sublingual, transdermal, rectal, some inhalation drugs, IMS, intravenous injection, and intrathecal injection
intrathecal injection
injection through the meninges around the spinal cord and into the subarachnoid space
2 major routes for drug adminstration
oral or parenteral (injection)
enteric-coated tablets
have a special coating that prevents breakdown until the tablet is in the intestine; helpful for preventing gastric ulcers or bleeding
oral tablets
have a long onset time and are simple to use; absorbed from the stomach, to the liver, then into the general circulation so some drug is lost
sublingual treatment
immediate delivery into blood and little drug is lost, simple and convenient to use
subcutaneous injection
requires a syringe and allows for slow absorption into the blood
IMS
requires syringe and has gradual absorption into the blood
intravenous injection
immediate onset and no drug loss; however, requires skill and equipment
inhalation of drugs
has rapid onset and little drug is lost
topical drugs
onset is rapid but absorption of the drugs varies
intraperitoneal pump
requires surgery and has an immediate onset
where are most drugs metabolised?
the liver
barriers to drug passage
the blood-brain barrier and the placental barrier
drug-receptor interaction
what receptor the drug interacts with (in the cell or at the cell membrane); can be enzymes, natural hormones, neurotransmitters, or electrolytes
agonist drug
the drug binds to a receptor and stimulates the same activity as the natural substance
antagonist drug
a drug binds to a receptor and inhibits the natural substance
beta-adrenergic blocking agents
bind to beta receptors in the SNS in the heart, preventing epinephrine from stimulating the heart to contract faster; works to decrease BP
4 categories of drug responses
dose effects, time effects, variability, and toxicity
what is drug administration a balance of?
giving an amount large enough to produce a therapeutic effect but not enough to create a toxic effect
what is a prescription?
a signed legal document that must include the patient’s name, address, and age, the prescriber’s name, address, and identification, the date, and the name and amount of drug, along with its route and directions
generic name
the unique, official, simple name for a specific drug
trade name
the brand name which is a trademark name used by a single manufacturer
example of generic vs trade name
advil is the trade name and ibuprofen is the generic name
FDA
regulates the production, labeling, distribution and other aspects of drug control
high risk drugs according to the FDA
are those with potential adverse effects and abuse
centre for disease control and prevention (CDC)
maintains a stock of drugs for rare infections that can only be obtained through consultation with the CDC
schedule II drug
has a high probability of abuse, ex. raw opium
schedule V drug
has less potential for abuse
clinical trials for drugs
have many safety guidelines and rules; has prolonged time periods; and many trials
