The NP is reading the literature about a drug. The article reports that the drug is potent. The NP knows that this means that the drug:
Produces its effect at low doses
Produces strong effects at any dose
Requires high doses to produce its effects
Is very likely to cause adverse effects
Except for gene therapy, which statements are true about drug-receptor interactions? SELECT ALL THAT APPLY
Drugs can mimic the actions of endogenous molecules.
Receptors for drugs do not respond to hormones and neurotransmitters produced by the body.
The binding of a drug to its receptor is usually irreversible.
Drugs can block the actions of endogenous molecules.
Drugs can give the cell new functions.
Which assessment findings suggest hypersensitivity of the receptors when a patient suddenly stops taking atenolol (Tenormin), a beta 2 receptor antagonist that slows the heart rate?
BP 80/56 mmHg
Pulse 118 bpm
Respirations 26 breaths/min
Temperature 104 degrees F (40 degrees C)
A patient who has over dosed on methadone HCL (Metadol), an opiate, is brought to the emergency department unresponsive with severely depressed respirations. The patient receives intravenous naloxone HCL (Narcan), an opiod antagonist, with a dramatic improvement in the level of consciousness and respiratory rate and effort within minutes. Which is the priority action 45-60 minutes after the naloxone HCL is administered?
Assess for the return of pain because the effect of the naloxone HCL should be peaking.
Assess the need to administer another dose of naloxone HCL because the respiratory and CNS depression may return as the medication effect ends.
Prepare to administer the drug intramuscularly if the drug has not taken effect.
Prepare to counter act the effects of the opiod withdrawal.
When the therapeutic index of a drug is narrow, what should the NP expect?
Blood levels of the drug would be monitored throughout the therapy.
The drug would produce the desired effect at low doses.
The drug would produce many adverse effects at low doses.
The drug would only be used in an emergency.
Pharmacodynamics includes the study of how drugs work.
Phase 2 of the dose response relationship starts at the point when the therapeutic effect does not increase with the increasing dose.
Maximal efficacy is defined as the largest effect that a drug can produce.
Potency is defined as the dose of drug needed to get the desired effect.
Two drugs in the same therapeutic class with different recommended doses (2mg vs. 200mg) can have equal effects.
A drug that stimulates a family of receptors that are transcription factors does not reach a therapeutic effect until taken regularly for 2wks.
A drug that is selective for specific receptors will produce more unintended effects than a nonselective drug.
If a drug is selective for specific receptors it is safe.
Affinity is the strength of attraction between a drug and its receptor.
Drugs with high intrinsic activity cause an intense response.
An agonist blocks the stimulation of a receptor.
If a receptor is constantly bombarded by a drug, the cell can down-regulate and decrease the response to the drug.
If a patient suddenly stops taking an antagonist drug, he can have a hypersensitivity of the receptor and overstimulation.
The ED 50 is usually the recommended dose for the drug.
Absorption
Change in drug structure; makes drug more hydrophilic
Change in drug structure/movement out of the body
Movement of drug from blood into tissues/cells
Movement of drug into and out of the body; what body does to drug
Movement of drug into the blood
Movement of drug out of the body
Distribution
Elimination
Excretion
Metabolism
Pharmacokinetics
Which of the following labs would suggest to the NP that a patient may be at risk for drug toxicity secondary to impaired excretion?
AST 72 IU
INR 4.2
eGFR 30mL/min
WBC 13,000 mm3
What is the priority action to assist a patient in PACU to promote excretion of most anesthetics?
Encourage deep breathing
Maintain a patent IV line
Monitor urine output
Prevent constipation
Lanoxin (Digoxin) is a drug with a narrow therapeutic index. Which interventions would be critical for the NP to implement? SELECT ALL THAT APPLY.
Administer the medication only on a PRN basis.
Monitor the patient for therapeutic and toxic effects
Be diligent about the timing of drug administration
Monitor blood levels of the drug
Teach the patient that the drug takes several weeks to reach its peak effect
Grapefruit juice inhibits the CYP 450 system enzymes (CYP3A4 enzyme specifically) and inhibits p-glycoprotein in the intestines for days after ingestion. This especially affects calcium channel blockers, benzodiazepines, cyclosporine, and “statin” drugs. The NP would explain to the patient that ingesting grapefruit juice causes:
Excessive first-pass effect
Excess levels of drug in the blood
Lack of therapeutic drug effect
Rapid excretion of the drug
A patient receiving Vancomycin for a serious infection, has been ordered to have a peak and trough level drawn. When would the NP order these blood levels to be obtained?
Peak level 1.5-hours after infusion and trough level 30 minutes before the next dose.
Peak level 1.5-hours before infusion is started and trough level immediately after infusion of the drug is completed.
Peak level while the drug is infusing and trough level trough level immediately after infusion of the drug is completed.
Peak level while the drug is infusing and trough level 30 minutes before the next dose.
A patient has stopped taking levothyroxine (Synthroid) 3 days ago. The drug has a half-life of 7 days. The patient tells the NP that the drug must not have been necessary because he/the patient does not feel any different. Which of the following is the basis of the NP’s explanation for this phenomenon?
The patient’s dose was probably too high, so the drug is still working.
The patient could not have been taking the drug as prescribed.
The drug probably was not needed if the pt. has not experienced symptoms.
The drug’s previous doses have not been completely eliminated from the body.
The NP prescribes the following medications for a patient: glyburide (Diabeta) 10mg by mouth daily for diabetes and quinapril HCL (Accupril) 20mg by mouth daily for hypertension. The NP should advise Quinipril (ACEI) potentiates the action of glyburide (sulfonylureas) so the patient should be cautioned to monitor for signs and symptoms of hypoglycemia. The dose of the glyburide may need adjustment. In addition, the meds (specially the glyburide) should be administered with breakfast.
Which of the following is true for a drug that acts as a reversibly-binding partial agonist?
The effect of the drug cannot be overcome by an increase in the endogenous agonist.
The drug will have an effect on the Emax of the endogenous agonist.
The drug will have an effect on EC50 of the endogenous agonist.
The drug will effectively decrease the efficacy of the endogenous agonist.
Which of the following is most dependent on a drug's EC50?
Drug potency.
Drug efficacy.
Volume of Distribution.
Therapeutic Index.
In the following illustration, which drug is the most efficacious?
A
B
A, C, & D are equally efficacious.
D
In the following illustration, if B is an endogenous agonist, A is most likely?
A competitive inhibitor.
A noncompetitive inhibitor.
An allosteric potentiator.
It is impossible to tell based in the information in this graph.
In the follow graph, which of the following parameters is a comparison of ED50 to LD50?
Therapeutic Index
Standard Safety Margin
Therapeutic Window
None of the above
Which of the following is not a factor influencing drug membrane passage?
Molecular size
Lipid solubility
Volume of distribution
Degree of ionization
Concentration gradient
The fraction of drug reaching circulation following administration is known by which abbreviation?
LD
MD
F
Vd
Which of the following routes of absorption are in the correct order in terms of rate of absorption?
intravenous = subcutaneous > inhalational > intramuscular > oral
intravenous = inhalational > subcutaneous > intramuscular > oral
intravenous = inhalational > intramuscular > oral > subcutaneous
intravenous = inhalational > intramuscular > subcutaneous > oral
Which of the following is true regarding the graph below?
Drug B has an availability equal to that of drug A.
Drug C has a rate equal to that of drug A.
The availability of B & C are dictated by their peak plasma concentration.
The difference in AUC between A and C dictate their relative availabilities.
Concerning drug receptor interactions, the constant Kd refers to: SELECT ALL THAT APPLY
maximal physiological effect
maximal binding
the drug concentration required to occupy 50% of receptors
drug concentration that results in half-maximal physiological response
Signal transduction involves G protein coupled receptor systems: SELECT ALL THAT APPLY
biogenic amines
peptide hormones
eicosanoids
Example(s) of second messenger effect(s): SELECT ALL THAT APPLY
increases in cAMP intracellular concentration
changes in intracellular calcium concentration
phosphoinositide effects
EC50 mainly reflects a drug's:
maximal effect
potency
lethality
ease of elimination
safety
Physiological processes mediated by the intracellular second messenger, cyclic AMP: SELECT ALL THAT APPLY
carbohydrate breakdown by the liver
decreased heart rate
increased contractility
smooth muscle relaxation
triglyceride breakdown
Drug effects are thought to be proportional to the number of occupied receptors
Nitric oxide mediates this effect on vascular smooth muscle:
smooth muscle contraction
no effect
Receptors are usually:
lipids
proteins
DNA
Longer-lasting physiological response to drug:
increase in heart rate following epinephrine infusion
changes in gene product production following corticosteroid injection.
True statement(s) concerning competitive inhibition: SELECT ALL THAT APPLY
competitive in addition is based on reversible drug/antagonist binding at receptor sites
with competitive inhibition, the dose-effects curve the shifted to the left
with competitive inhibition, maximal drug effect cannot be obtained, even at high agonist concentrations
Example(s) of endogenous ligands that interact with membrane-integrated ion channels and affect(s) ion conductance. SELECT ALL THAT APPLY
acetylcholine
GABA
glutamate
aspartate
glycine
Example(s) of (a) receptor(s) which is/are enzyme(s): SELECT ALL THAT APPLY
dihydrofolate reductase
acetylcholinesterase
monoamine oxidase
Primary mechanism by which cAMP effects are terminated:
enzyme-catalyzed dephosphorylation
reuptake into presynaptic nerve terminals
An example of a receptor which is a structural protein.
Na/K ATPase
tubulin
phospholipase C
An example of an agent that exerts much of its effects through intracellular receptors that in complex form binds to DNA response elements:
dopamine
corticosteroids
diltiazem
atropine
Factors that may cause variation in drug responsiveness:
changes in the number or function of receptors
tachyphylaxis
idiosyncratic drug responses
hypersensitivity reactions
all of the above
Major roles of receptors:
determine rate of drug elimination
determine drug action selectivity
provide a means of blocking drug action as well as mediating drug action
act as drug storage sites
Concerning oral administration -- disadvantages SELECT ALL THAT APPLY
least economical
drug taken orally may cause emesis
drug taken orally may be destroyed by gastric acidity
drug taken orally may be metabolized by gastrointestinal flora
drug taken orally may be inconsistently absorbed due to the presence of food
Factors That Can Affect Pharmacokinetics SELECT ALL THAT APPLY
Age
Hepatic or renal disease
Pregnancy
Drug interactions
Ethnicity
Nutritional status in patients
GI surgeries
Drug-drug interactions
Drug-food interactions
Factors That Affect Bioavailability: SELECT ALL THAT APPLY
How drug is transported across membranes
How drug is affected by
Shape of the medication
Gastric acid
Drug formulation: salt form, type of binders
Enzymes in GI tract
Factors affecting absorption: SELECT ALL THAT APPLY
Formulation
Mechanics of absorption
pH
Lipophilicity
2nd messengers
Cellular environment
Ionization
Most drugs are strong acids (-) or bases (+)
Uncharged drugs are more lipid soluble
Ionized drug molecules more lipid soluble
You can create a non-ionized form of an acidic drug by placing it in an acidic environment
Drugs with low molecular weight pass through membrane pores more easily
Active transport is drug movement from area of higher concentration to lower concentration
Biotransformation reactions occur first with Phase I followed by Phase II.
CYP cytochromes are non-specific, so they could all act on the same drugs.
Biotransformation occurs: SELECT ALL THAT APPLY
liver
intestines
skin
lungs
kidney
brain
muscles
heart
During Phase II biotransformation, drugs can conjugate with which of the following:
glucoronic acid
sulphuric acid
acetic acid
amino acid
Conjugation occurs during Phase I of biotransformation
Enzyme induction can cause potential toxicity
Only certain drugs are hepatotoxic
Alcoholism and fatty liver disease affect drug metabolism
Factors that affect drug metabolism: SELECT ALL THAT APPLY
Comorbidities
Liver dysfunction
Gender
In an 18-month-old baby, these factors could affect biotransformation:
P-450 enzymes not fully developed
blood brain barrier not fully developed
intestinal enzymes not fully developed
renal system not fully developed
none of the above
A drug must be biotransformed to be excreted
Clearance is the sum of elimination from liver, kidneys, and GI tract.
All drugs are excreted by the kidneys.
After age 40 50 60 70( 40, 50, 60, 70 ) people lose 5 7 10 15( 5, 7, 10, 15 ) percent of kidney nephrons every decade.
You see a pt with HTN. You've given him a prescription for an antihypertensive BID. He returns in 30 days and his blood pressure is 150/85. He admits to noncompliance with BID dosing. You educate him about the importance of taking the medication as prescribed, because once daily is not enough to maintain adequate blood levels. This is an example of:
Dose of medication is too low and needs to be increased
Steady state
Increased renal clearance of medication
A patient is taking multiple doses of 100 mg of metoprolol. At what does of medication will the patient reach steady state? mg
A patient is given a single dose of morphine for pain relief before leaving the hospital. Since he can't drive while under the influence, he wants to know how long until he can drive. The half-life if morphine is 2 hours. What is your answer?
2 hours
4 hours
6 hours
8 hours
10 hours
What substances are excreted via the lungs?
Alcohol
Liquid
Gas
Volatile substance
Your pregnant patient develops a DVT. You place her on heparin. She mentions she doesn't like shots. Should you place her on warfarin instead to increase medication compliance?
Yes, drug compliance is very important. Because DVTs are so serious, increasing drug compliance is the primary concern.
No, heparin is better for the baby.
Until age 2, children have 70 75 80 85( 70, 75, 80, 85 )% body water, in contrast to adults, who have 50 55 60 65( 50, 55, 60, 65 )%.
Despite differences in body makeup, infants and children have consistent rates of absorption.
A laboratory is conducting a study to assess the safety, efficacy, and potency of a group of drugs before allowing the agents to proceed to clinical trials. The figure shows the dose-response curves for four different drugs from the same class of medications (Drugs A, B, C, & D). Which of the following is true regarding these medications?
Drug A has greater efficacy than Drug D
Drug D has greater efficacy than Drug A
Drug A has greater potency than Drug D
Drug D has greater potency than Drug A
All four drugs (A,B,C,D) have equal potencies
An overweight patient comes to see you about heart palpitations and high blood pressure. You're trying to decide between a once-daily beta blocker and one given every 6 hours. You feel the once-daily is the best choice. Is this correct?
Yes, this is the best choice because once-daily will help with medication compliance.
No, this is not the best choice because your patient is overweight.
Characteristics of fat-soluble drugs: cell membrane potential ❌ pH ❌ molecular size ❌ Half-life ❌ Vd ❌ Ionization ❌ Absorption ❌ Route of administration ❌ Metabolized by ❌
Characteristics of water-soluble drugs: cell membrane potential ❌ pH ❌ molecular size ❌ Half-life ❌ Vd ❌ Ionization ❌ Absorption ❌ Route of administration ❌ Metabolized by ❌
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