Terms & such
What is the mechanism of action for agonist drugs?
They activate receptor sites by binding with them and mimic endogenous chemicals (neurotransmitters, hormones, etc)
Name the four components of pharmacokinetics
ADME
absorption, distribution, metabolism, excretion
When can a drug be used by the body: free or bound to albumin?
Free drugs can act
What three food/food-derived diet precautions should be considered with drug interactions?
dairy, foods containing vitamin K, and grapefruit juice
What does the therapeutic index indicate?
DOUBLE POINTS: what is the ratio that determines therapeutic index?
the safety of a drug
ratio = LD50 (lethal dose)/ED50 (effective dose)
How do antagonist drugs work?
exert no effect on receptor of their own, but block the receptor from binding to an agonist to exert effect
ex: antihistamine
Explain the first pass effect: definition and implication
oral medications pass through the GI tract, and some are destroyed by stomach acid, leaving only 5-10% bioavailable.
Should not be given PO
ex: nitroglycerin SUBL
Single Nucleotide Polymorphisms or SNPs ("snips")
Which three medication classes are the most people allergic to?
penicillin, NSAIDs, and sulfa drugs
Which organ are most drugs eliminated through AND what 3 labs would you check to ensure no toxicity is occurring?
kidneys; check BUN, GFR & creatinine to check for nephrotoxicity
What is pharmacodynamics?
hint: C & E
how a drug influences target cells --> subsequent changes in the body's biochemical reactions
How are drugs metabolized in the liver?
The cytochrome 450 system, which uses isoenzymes such as 3A4
What are two mechanisms of action for drugs that do not involve receptor sites?
idiosyncratic is an unusual and unexpected response likely due to genetic predisposition
iatrogenic effect is when a drug causes a disease process
Name a similarity AND a difference between Schedule I and Schedule II drugs
BOTH have high abuse potential
only Schedule II are used medically [ex: opioids(II) vs heroin(I)]
What are you monitoring when giving medications? (3 things)
vitals (especially O2 sat), mental status (2), side effects
How many half-life cycles may be required before steady state is achieved between tissue and blood concentrations? What does this mean practically?
5 half-life cycles
some drugs might not be fully effective for days/weeks (ex: SSRIs)
How does the liver prepare drugs for excretion?
What type of drug reaction causes birth defects?
DOUBLE POINTS: name three drugs or classes of drugs that are category X
teratogenic effects
examples: isotretinoin (Accutane), fluoroquinolones, aminoglycosides, tetracyclines, Bactrim
Don't Forget About The Babe
How do prodrugs work?
They are inactive compounds when administered to the patient, but the liver converts the compound to active metabolites to exert the desired effect
ex: clopidigrel
right: drug, dose, dude (patient), documentation, route, time, evaluation (we know these)
+ patient education, and refusal
Explain how CYP 450 Inducers work
A drug that uses CYP isoenzyme 3A4 for metabolism is ordered. A second drug is ordered, which induces CYP 3A4. The first drug's concentration decreases as a result. The first drug's dose needs to increase.
The first drug is ordered that uses CYP isoenzyme 3A4 for metabolism. A second drug is ordered which inhibits CYP 3A4. The first drug's concentration will be increased, putting the patient at risk for toxicity. The dosage of the first drug must be decreased.
What are the SIX different types of drug interactions we need to know?
hint: think about actions on receptors
additive, displacement, antagonism, interference, synergism, incompatibility
A DAISI
What is the difference between Schedule III and Schedule IV drugs?
III - combination drugs with less abuse potential (ex: Tylenol + codeine)
IV - medically indicated with mild physical/psychological dependence (ex: benzos)