Unit 1 Flashcards
Pharmacokinetics
describes the four stages a drug goes through in the body: absorption, distribution, metabolism, and excretion
the process a drug goes through in our body is?
ADME: absorption, distribution, metabolism, and excretion
Pharmacodynamics
refers to the effects of drugs in the body and the mechanism of their action
Drug bioavailability
the ability of a drug or other chemical to be taken up by the body and made available in the tissue where it is needed
Pharmacogenetics
the study of how people’s genes affect their response to medicines
Pharmacognosy
the study of natural products and their potential for medicinal use
Toxicology
the study of how chemicals, substances, and situations can harm living organisms and the environment
Pharmacoeconomics
measuring costs and outcomes associated with the use of pharmaceuticals in health-care delivery
Where does a medication get distributed after consumed orally?
It goes through stomach -> liver -> portal circulation
The first pass effect
the inactivation of orally or enterally administered drugs in the liver and intestines by enzymes
What is the transdermal route of medication delivery beneficial for?
medication that must be administered over a longer period of time to control symptoms
Side effect
anticipated, well-known consequence of the drug targeting other cells rather than just its target cell
Adverse effect
unanticipated effect of a drug that may be harmful to the patient
Free/unbound drug
the portion of the drug that is dissolved in plasma water
T/F: only free and unbound drugs will pass from the bloodstream to tissues where drug-receptor interactions will occur.
True. The protein-bound portion of the drug is inactive.
Blood-brain barrier
tightly woven mesh of capillaries that protect the brain from potentially dangerous substances, such as poisons or viruses
What can get through the blood-brain barrier?
Only certain medications made of lipids (fats) or those with a “carrier” can get through the blood-brain barrier
Everything that enters the bloodstream is metabolized by ______
the liver
Biotransformations
chemical metabolizing done by the liver
Phase I-III biotransformations
Phase I - change an inactive drug -> active called a prodrug. Prodrugs improve a medication’s effectiveness.
Phase II - couple the drug molecule with another molecule in conjugation to change it from active -> inactive again to be excreted.
Phase III - may also occur after Phase II, but not always. This is where conjugates & metabolites are excreted from cells.
Disruptions of drug metabolism:
depot binding and enzyme induction
Depot binding
the coupling of drug molecules with inactive sites in the body, resulting in the drug not being accessible for metabolism
Enzyme Induction
Enzymes are induced by repeated use of the same drug, so the body becomes accustomed to the constant presence of the drug and compensates by increasing the production of the enzyme necessary for the drug’s metabolism. This contributes to a condition referred to as tolerance and causes clients to require ever-increasing doses of certain drugs to produce the same effect
What is the most common route of drug excretion?
The kidneys
Drugs that share metabolic pathways may inhibit metabolism because….
they can “compete” for the same binding sites on enzymes, thus decreasing the efficiency of their metabolism.
Mechanism of action (MOA)
describes how a medication works in the body
Agonist drug
binds tightly to a receptor to produce a desired effect
Antagonist drug
competes with other molecules and blocks a specific action or response at a receptor site
Generic drugs
the drug names we will want to study for NCLEX. They have (by FDA law) the same chemical formula as brand name drugs, but different additives
Steady state
refers to the point at which the amount of drug entering the body is equal to the amount of drug being eliminated, resulting in a stable drug concentration
Half-life
the time it takes for the amount of a drug’s active substance in your body to reduce by half
Therapeutic window
window between the (minimally) effective concentration and the toxic concentration where the safest and most effective treatment will occur
Peak and trough labs
A peak drug level is drawn after the medication is administered and is known to be at the highest level in the bloodstream. A trough level is drawn when the drug is at its lowest in the bloodstream, right before the next scheduled dose is given
Therapeutic index
a quantitative measurement of the relative safety of a drug.
High vs low therapeutic index
High = safe
Low = not as safe and should be titrated
Drug selectivity
the separation between the desired and undesired effects of the drug
Duration of action (DOA)
how long the drug works for before you need to give the drug again
Additive effects
Drug 1 + Drug 2 = work together to make something
Synergistic effects
Drug 1 + Drug 2 = enhance each other and produce greater effect than alone.
Antagonistic effects
Drug 1 + Drug 2 = work against each other and may cancel out effects
Adverse drug events (ADEs)
any injury caused by taking a medication
What is the most common ADE?
medication error
What age groups should we pay special attention to when administering drug doses?
Pediatrics (infants, neonates, school age) - underdeveloped systems like livers and kidneys that cannot metabolize drugs as quickly as adults, resulting in higher concentrations of the drug in the bloodstream
Pregnant & breast-feeding women - hardly any drugs tested on pregnant women, so they may harm the fetus. Many drugs can also be passed in breastmilk to the newborn, and that’s not safe.
Elderly patients - polypharmacy ; cognitive decline making medication instructions hard to follow correctly ; decreased function in body systems (muscle mass, protein carriers, liver & kidneys)
CSA Drug Schedules
Schedule 1 - no accepted legal medicinal use and very high risk for addiction/abuse. (heroin, LSD, GHB, MDMA, marijuana, etc).
Schedule 2 - Restricted legal medicinal use. High potential for physical and/or psychological dependence. High risk for addiction/abuse. (cocaine, codeine, morphine, opium, etc).
Schedule 3 - Accepted legal medicinal use. Lower potential for physical dependance, but high potential for psychological dependence specifically. Moderate risk for addiction/abuse (anabolic steroids, ketamine, vicodin, testosterone, etc). Schedule 4 - Accepted legal medicinal use. Low potential for physical and/or psychological dependence. Low risk for addiction/abuse (ambien, ativan, rohypnol, xanax, etc).
Schedule 5 - OTC. Legal without prescription.
Drug diversion
transferring a legally prescribed controlled substance from the individual for whom it was prescribed to another person for any illicit use
What is the worst form of drug diversion?
Tampering (taking medication out of syringes or prepared packages and replacing it with a fake like saline)
Maleficence vs beneficence
Maleficence - the intentional act of causing harm to another person
Beneficence - the obligation to do good and promote the well-being of patients
8 Rights of Med Administration:
- Right patient: Check using two patient identifiers
- Right medication
- Right dose
- Right route
- Right time
- Right documentation: Always verify any unclear or inaccurate documentation prior to administering medications.
- Right reason: If signs and symptoms no longer warrant administration of the prescribed medication, notify the prescribing provider.
- Right response: The prescribing provider should be notified if expected outcomes are not achieved or if adverse effects occur
Common medication errors:
- Error prone abbreviations (BID, PRN, etc - most of these are written out now to avoid miscommunication on them)
- Do Not Crush Meds (it’s really important not to crush meds that can’t be crushed like extended releases! If you’re not sure, look it up)
- Look-Alike and Sound-Alike Drugs (Adderall and Inderal , etc)
- Boxed Warnings (pay attention to those Black box warnings and take care to their effects and the way they must be administered_
APINCH
Black Box drugs.
A - antimicrobials (the -mycin family and amphotericin)
P - Potassium & other electrolytes (injections of concentrated electrolytes)
I - Insulin
N - Narcotics (opioids, anesthetics, and sedatives)
C - Chemotherapeutic agents (methotrexate, etc)
H - Heparin and other anticoagulants (Warfarin, etc).
Which ways can drugs be excreted?
renal, glandular, pulmonary, and fecal
T/F: Blood flow to the liver decreases with age
True
Do newborns have more fat than water?
No, they have more water than fat (75% water).
