Pharmacology Week 2, Exam 1: Drug Action and Geriatrics

What is pharmacokinetics?

the study of drug movement throughout the body

What are the four aspects of pharmacokinetics?

Absorption

Distribution

Metabolism

Elimination

What is pharmacodynamics?

The study of the body's physiologic response to changes in drug concentration, effects of drugs on the body

What is bioavailability?

the percentage of administered drug available for activity

What is absorption?

how we get a drug into our bodies circulation

what are some medications enteric coated?

to allow the drug to bypass and resist disintegration in the stomach acids till it reaches the small intestine

can enteric coated medications be crushed?

no

which form of medication is absorbed the quickest

injections: either given subcutaneously, intramuscular, or intravenous

What is the first pass effect?

The metabolism of a drug and its passage from the liver into the circulation

What is protein binding?

As drugs circulate in the blood and plasma, some of them have a high affinity for binding to the plasma proteins (albumin). The drugs are stuck and bind to the proteins

What is albumin?

protein

What are free drugs?

drugs that are not bound or attached to a protein

what organ does most of the metabolism take place?

liver

What is duration?

The period when a drug's concentration is sufficient to cause a therapeutic response

What are side effects?

secondary drug effects

What is a half-life?

the time it takes for the amount of drug in our body to reduce by half

What are adverse drug reactions?

any undesirable or unintended effect following administration of a drug

What is metabolism?

The process by which the body chemically changes drugs into a form that can be excreted

What is distribution?

transport of a drug by the bloodstream to its site of action

What is excretion?

removal of drugs from the body

What organ is responsible for excretion?

kidneys

What is the dose-response relationship?

the body's physiologic response to changes in drug concentration at the site of action, the effects

what does onset mean?

time it takes for drug to reach minimum effective concentration after administration

what does peak mean?

The highest concentration of the drug in the blood, when it's most impactful

what is trough drug level?

Point in time when a drug is at its lowest level in the body, measured rate at which drug is eliminated

what is the ligand-binding domain?

the site on the receptor at which drugs bind

What are drug interactions?

Altered drug effect due to interaction with another drug, nutrient, disease, or tests

what are the two categories of drug interactions?

pharmacokinetic and pharmacodynamic interactions

what is maximal efficacy?

the point at which increasing a drug's dosage no longer increases the desired therapeutic response

What is potency?

amount of drug needed to elicit specific physiologic response

What is enteric coating?

coating on meds that allow it to be dissolved in the small intestine

what is drug dissolution?

dissolving of solid dosage forms and their absorption from the GI tract, they disintegrate into small particles and combine with a liquid to form a solution

What is an antagonist drug?

a drug that blocks the receptor so they can't be activated, reduces or blocks effect of second drug

What are agonist drugs?

drugs that activate receptors and produce a desired response

what are nonspecific drugs?

drugs that affect multiple receptor SITES

ex: heart or BV

what are nonselective drugs?

drugs that affect multiple receptors

ex: alpha or beta

What is drug toxicity?

occurs when drug levels exceed the therapeutic range

what is the therapeutic range?

a range of doses that produce a therapeutic response without causing significant adverse effect in patients

what is a photosensitive drug?

A medication that can cause skin reactions when patient is exposed to the sun

What is the therapeutic index?

The ratio between the toxic dose and the therapeutic dose

what is drug disintegration?

Breakdown of oral drug form into small particles

what is a loading dose?

An initial higher dose of a drug that may be given at the beginning of treatment

what does polypharmacy mean?

The use of more medications than is medically necessary

What is the synergistic drug effect ?

the clinical effect of the two drugs given together is substantially greater than that of either drug alone

what is duration of action in drugs mean?

the length of time the drug exerts a therapeutic effect

A patient has liver and kidney disease. He is given a medication with a half-life of 30 hours. What is the expected duration of this medication?

A. increase.

B. decrease.

C. remain unchanged.

D. dissipate.

A

When assessing older adults and those with renal dysfunction, the nurse would expect the creatinine* clearance to be which of the following?

A. substantially increased.

B. slightly increased.

C. decreased.

D. in the normal range.

C

A patient sustains significant burns to the skin and is experiencing fluid shift associated with edema in the fluid overload phase. The nurse would anticipate that this will interfere most with which phase of pharmacokinetics?

A. Absorption

B. Distribution

C. Metabolism

D. Excretion

B

What is steady state?

when the rate of drug administration equals the rate of excretion

what is tolerance?

decreased responsiveness to a drug over the course of therapy

What is tachyphylaxis?

an acute, rapid decrease in response to a drug

what is the Placebo effect?

a drug response not attributed to the chemical properties of the drug

drugs that are administered by other than the oral route are able to bypass

disintegration and dissolution

Which nursing actions would be most appropriate for ensuring patient safety with a medication that has a low therapeutic index?

A. Monitoring the patient's urine output.

B. Assessing vital signs hourly.

C. Maintaining strict isolation precautions.

D. Monitoring serum peak and trough levels

D

What is the primary site of metabolism for most drugs?

A. Kidney

B. Small Intestine

C. Liver

D. Brain

C

When administering medications to the older adult population, the nurse is aware that the physiologic changes of aging that can affect drug activity include all of the following EXCEPT

A. increased fat-to-water ratio.

B. decreased liver enzyme production.

C. loss of nephrons.

D. increased gastrointestinal blood flow.

D

Adverse reactions and drug interactions occur frequently in older adults due to all of the following except

A. consumption of numerous drugs owing to multiple chronic illnesses.

B. drugs ordered by several health care providers.

C. increased incidence of allergic responses.

D. self-medication with OTC preparations.

C

Older adults are at risk for taking many medications together. This is known as:

A. tachyphylaxis.

B. drug interaction.

C. polypharmacy.

D. tolerance.

C

Which is a physiologic change seen in the older adult that has an effect on drug administration?

A. Lower (acidic) gastric secretions

B. Increased first-pass effect through the liver

C. Increased glomerular filtration rate

D. Lower cardiac output

D, Lower cardiac output

what group of patients are considered geriatric

those 65 and older

physiologic changes in geriatrics

Reduction in total body water and lean body mass, kidney mass and function, liver mass and function, and in physiologic processes that maintain equilibrium

What is the Beers criteria?

lists potentially inappropriate drugs that lead to adverse effects in the elderly

nonadherence could cause both

underdosing and overdosing

What should you take into consideration when health teaching older adults

your tone, avoiding elder speak, limiting distractions, using large prints and bright colors, face the patient when speaking, clean eyeglasses, and the function of possible hearing aids

What is the rate of dissolution?

the time it takes the drug to disintegrate and dissolve to become available for the body to absorb it

Drugs in _____ form are more rapidly available for GI absorption than are _________.

liquid, solid

factors affecting drug absorption

blood flow, pain, stress, hunger, food, pH

are drugs given intramuscularly or subcutaneously absorbed faster and why

intramuscularly, due to faster blood flow/circulation

What is the blood-brain barrier?

The protective barrier that prevents certain substances from entering the brain

metabolism is also called

biotransformation

What is a prodrug?

a compound that is metabolized into an active pharmacologic substance, often designed to improve drug bioavailability

what are two common tests to determine renal function

creatinine and blood urea nitrogen (BUN)

Which components of pharmacokinetics does the nurse need to understand before administering a drug? (Select all that apply.)

a. Drugs with a smaller volume of drug distribution have a longer half-life.

b. Oral drugs are dissolved through the process of pinocytosis.

c. Patients with kidney disease may have fewer protein-binding sites and are at risk for drug toxicity.

d. Rapid absorption decreases the bioavailability of the drug.

e. When the drug metabolism rate is decreased, excess drug accumulation can occur, which can cause toxicity.

C and E

The nurse will question the health care provider if a drug with a half-life ( t ½) of more than 24 hours is ordered to be given more than how often?

a. Once daily

b. Every other day

c. Twice weekly

d. Once weekly

A

The nurse is explaining drug action to a nursing student. Which statement made by the nurse is correct?

a. Water-soluble and ionized drugs are quickly absorbed.

b. A drug not bound to protein is an active drug.

c. Most receptors are found under the cell membrane.

d. Toxic effects can result if the trough level is low.

B

A Native American patient is newly diagnosed with type 2 diabetes mellitus and is prescribed the antidiabetic drug metformin 500 mg by mouth with morning and evening meals. Which statement best indicates to the nurse that the patient will adhere to the therapeutic regimen?

a. I will no longer put sugar on my cereal because that will help me be healthier.

b. If I take this medicine, I will feel better soon and won't have to take it anymore.

c. To reduce the possibility of damage to my body, I must take the medicine as scheduled.

d. I have diabetes because of my ancestry, so there's not much I can do about it.

A

The nurse is aware that the rate of absorption can be changed by which actions? (Select all that apply.)

a. Modifying gastric emptying time

b. Changing gastric pH

c. Decreasing inflammation

d. Forming drug complexes

e. Eating too slowly

A, B, and D

The nurse is meeting with a community group about drug safety. The nurse must emphasize that patients at high risk for drug interactions include which groups? (Select all that apply.)

a. Older patients

b. Patients with chronic health conditions

c. Patients taking three or more drugs

d. Patients dealing with only one pharmacy

e. Patients covered by private insurance

A, B, and C

The nurse is describing to a patient the synergistic effects of two of his medications. Which statement by the nurse is correct about synergistic drug effects?

a. Two drugs have antagonistic effects on each other.

b. The action of a drug is nullified by another drug.

c. One drug acts as an antidote to the side effects of another drug.

d. A greater effect is achieved when two drugs are combined.

D

A patient asks the nurse about drug interactions with over-the-counter preparations. Which is the nurse's best response?

a. Discuss this with the health care provider.

b. There are not many interactions, so don't worry about it.

c. Read the labels carefully, and check with your health care provider.

d. Avoid over-the-counter preparations.

C

A patient has nine drugs prescribed to take daily. Which are common reasons for nonadherence to the drug regimen in an older adult? (Select all that apply.)

a. Taking multiple drugs at one time

b. Impaired memory

c. Decreased dexterity

d. Increased mobility

e. Increased visual acuity

A, B, and C

The nurse is reviewing a patient's list of drugs. The nurse understands that the older adult's slower absorption of oral drugs is primarily because of which phenomenon?

a. Decreased cardiac output

b. Increased gastric emptying time

c. Decreased gastric blood flow

d. Increased gastric acid secretion

C

The older adult patient has questions about oral drug metabolism. Information on what subject is most important to include in this patient's teaching plan?

a. First-pass effect

b. Enzyme function

c. Glomerular filtration rate

d. Motility

A

The nurse is developing teaching materials for an 82-year-old man with macular degeneration, who is being discharged on two new drugs. Which strategies would be best to use to impart the information? (Select all that apply.)

a. Limit distractions in the room when teaching.

b. Wait until discharge to teach so information is fresh in the memory.

c. Augment teaching with audio material.

d. Use "Honey" and other terms of familiarity when addressing him to promote trust.

e. Use large, dark print on a light background for written material.

A, C, and E

Which changes with aging alter drug distribution? (Select all that apply.)

a. An increase in muscle mass and a decrease in fat

b. A decrease in muscle mass and an increase in fat

c. A decrease in serum albumin levels

d. An increase in total body water

e. A decrease in kidney mass

B, C, and E

Which factors contribute to polypharmacy in older adults? (Select all that apply.)

a. Multiple health care providers

b. Multiple chronic diseases

c. Use of a single pharmacy

d. Care coordination by a nurse

e. Few hospitalizations

A and B

Which is the best measure for the nurse to use to determine a patient's kidney function?

a. Creatinine clearance

b. Estimated glomerular filtration rate

c. Serum creatinine level

d. Blood urea nitrogen level

B

A patient asks the nurse why a lower dose of intravenous pain medication is being given than the previous oral dose, what is the nurses best response based on?

Mediations given intravenously are not affected by the first-pass effect

Drug half-life is defined as the amount of time required for 50% of a drug to

be eliminated by the body

Patients with renal failure would most likely have problems with which phase of pharmacokinetics?

elimination

What does Pharmacokinetics study?

distribution rates among various body compartments

To achieve the most rapid onset of action, the health care provider will prescribe the medication to be administered by which route?

Intravenously

The patient is taking a drug that has a half life of 24 to 30 hours. In preparing discharge teaching, what is the dosing schedule the nurse anticipates will be prescribed?

once a day

The nurse is caring for a patient is receiving two different drugs. At current dosages and dosage forms, both drugs are absorbed into the circulation in identical amounts. What are these drugs considered?

bioequivalent

Which drug form is most rapidly absorbed from the gastrointestinal (GI) tract?

a. Capsule

b. Sublingual

c. Liquid

d. Tablet

C

Which organ of the body allows the disintegration of enteric-coated tablets to occur?

a. Colon

b. Liver

c. Small intestine

d. Stomach

C

What affect does food have on the dissolution and absorption of oral drug?

a. Increases

b. Decreases

c. Has no effect on

d. Prevents

B

Which statement places the four processes of pharmacokinetics in the correct sequence?

a. Absorption, metabolism, distribution, excretion

b. Distribution, absorption, metabolism, excretion

c. Distribution, metabolism, absorption, excretion

d. Absorption, distribution, metabolism, excretion

D

Which type of drug passes rapidly through the gastrointestinal (GI) membrane?

a. Lipid-soluble and ionized

b. Lipid-soluble and nonionized

c. Water-soluble and ionized

d. Water-soluble and nonionized

B

Which factor most commonly affects a drug's absorption? (Select all that apply.)

a. Body mass index

b. Hypotension

c. Pain

d. Sleep

e. Stress

B, C, and E