What is the rationale for the administration of a loading dose of a drug Quizlet

a) A reduction in the dosage of the drugs
b) A change in the timing of medication administration
e) More frequent monitoring for adverse drug effects

The liver is the primary site of drug metabolism. Patients with severe liver damage, such as that caused by cirrhosis, will require reductions in drug dosage because of the decreased metabolic activity. Even with decreased dosage, more frequent monitoring is required to detect adverse drug effects that may be related to impaired metabolism. A change in the timing (e.g., lengthening time between doses) may be needed for some drugs, but not all, and a drug dosage that is too large for the liver to metabolize may still cause harm even if doses are spaced further apart.

The nurse is discussing how the body handles medications after administration. Which process should the nurse include in the​ discussion? (Select all that​ apply.)

A.
Metabolism
B.
Ingestion
C.
Excretion
D.
Absorption
E.
Distribution

A.
Metabolism
C.
Excretion
D.
Absorption
E.
Distribution

The processes of pharmacokinetics are grouped into four​ categories: absorption,​ distribution, metabolism, and excretion. All four of these processes have drug movement in common. Ingestion refers to oral administration of​ medications, which occurs prior to pharmacokinetic processes.
Next Question

The nurse is reviewing medications and their effects on the body. Which process should the nurse identify that describes how drugs move into their target​ cells? (Select all that​ apply.)

A.
Diffusion
B.
Absorption
C.
Active transport
D.
Metabolism
E.
Capillary blockade

A.
Diffusion
C.
Active transport

Drugs use two primary processes to cross​ membranes: diffusion and active transport. Absorption and metabolism are pharmacokinetic processes that occur after the medication has been administered. Capillary blockade is a mode of bodily uptake for radioactive tracers.

A client is prescribed a drug that does not need to enter the body cells to be effective. In which way should this drug produce physiologic​ effects?

A.
Diffuse through body fluids
B.
Stimulate white blood cells to transport the drug to the body site
C.
Activate secondary messengers within the cell
D.
Alter the chemistry of blood cells

C.
Activate secondary messengers within the cell

Drugs may not need to enter the cell to produce their effects. Once bound to​ receptors, located on the plasma​ membrane, some drugs activate second messengers within the​ cell, which produce physiologic changes. These drugs do not diffuse through body​ fluids, alter the chemistry of blood​ cells, or stimulate white blood cells to transport the drug to the body site.

The nurse is discussing pharmacokinetics with a group of colleagues. Which type of drug molecule should the nurse explain that moves through the cell membrane by simple​ diffusion? (Select all that​ apply.)

A.
Nonionized
B.
Lipid soluble
C.
Water soluble
D.
Small
E.
Ionized

A.
Nonionized
B.
Lipid soluble
D.
Small

Drug molecules that are​ small, nonionized, and lipid soluble will usually pass through plasma membranes by simple diffusion and easily reach the target cells. Ionized drugs and​ water-soluble agents have difficulty crossing plasma membranes by simple diffusion. These agents may require a​ carrier, or transport proteins to cross membranes

The nurse is planning to administer medications to a client. Which factor should the nurse expect when cells use active transport to move drugs into the​ cells?

A.
Open channels in the plasma membrane
B.
Ionization
C.
Energy
D.
​Water-solubility

C.
Energy

Some drugs cross membranes against their​ gradient, from low concentration to high​ concentration, through the process of active transport. This requires expenditure of energy on the part of the cell. A carrier protein.​ Ionization, water-solubility, or open channels in the plasma membrane are not required for active transport.

A client has a body temperature of​ 102° F. Which form of acetaminophen should the nurse request to increase the absorption​ rate?

A.
Liquid
B.
Capsule
C.
Uncoated tablet
D.
​Enteric-coated tablet

A.
Liquid

Tablets and capsules must dissolve before the medication is available for absorption. Because oral liquid formulations do not undergo​ dissolution, they are absorbed faster than​ capsules, uncoated​ tablets, and​ enteric-coated tablets.

The nurse prepares medications for a client. For which reason should the nurse expect the client to have difficulty absorbing​ medications?

A.
Decreased cardiac output
B.
Elevated blood glucose level
C.
Elevated blood pressure
D.
Decreased bowel motility

D.
Decreased bowel motility

Absorption of medications affected by digestive motility. Changes in gastrointestinal motility may either speed up or slow down​ absorption, depending on the drug and where it is absorbed. Elevated blood​ pressure, decreased cardiac​ output, or elevated blood glucose do not affect the absorption of medications.
Next Question

The nurse is considering routes of administration prior to administering a medication to a client. Which route should the nurse expect to have the fastest level of​ effectiveness? (Select all that​ apply.)

A.
Intravenous
B.
Oral
C.
​Intra-arterial
D.
Intramuscular
E.
Subcutaneous

A.
Intravenous
C.
​Intra-arterial

Drugs administered intravenously​ (IV) or​ intra-arterially directly enter the bloodstream. This causes rapid absorption to the tissues after the infusion. Drugs administered by the​ oral, subcutaneous, or intramuscular routes take longer to absorb.
Next Question

A client is prescribed medications to be given through a gastrostomy tube. Which action should the nurse take to ensure the fastest absorption of these​ medications?

A.
Crush the medications together
B.
Use a liquid form of the medication
C.
Flush the tube with water after administering
D.
Dissolve the medications in water

B.
Use a liquid form of the medication

Liquid formulations of an oral drug are absorbed faster than tablets or capsules of the same drug. Crushing the medications​ together, dissolving the medications in​ water, or flushing the tube with water after administering will not ensure that the medications are absorbed faster.
Next Question

The nurse collects health history information from a pregnant client. For which reason should the nurse remind the client to avoid taking any type of​ medication?

A.
The doses of the medications need to be adjusted higher before taking
B.
The doses of the medications need to be adjusted lower before taking
C.
Drugs can easily cross the​ fetal-placental barrier
D.
Pregnancy renders medications ineffective

C.
Drugs can easily cross the​ fetal-placental barrier

The
fetal-placental
barrier serves an important protective function because it prevents potentially harmful substances from passing from the​ mother's bloodstream to the fetus. Substances such as​ alcohol, cocaine,​ caffeine, and certain prescription​ medications, however, easily cross the
fetal-placental
barrier and can potentially harm the fetus. Because of​ this, a client who is pregnant should not take any prescription​ medication, over-the-counter​ (OTC) drug, or dietary supplement without first consulting a healthcare provider. Medications in pregnancy are not avoided because they are rendered ineffective or because the dose needs to adjusted higher or lower

The nurse is preparing to administer an inhaler to a client. Which factor should the nurse identify that affects respiratory excretion of this​ medication? (Select all that​ apply.)

A.
Water solubility
B.
Transport proteins
C.
Diffusion
D.
Pulmonary blood flow
E.
Gas solubility

C.
Diffusion
D.
Pulmonary blood flow
E.
Gas solubility

Drugs delivered by gas or volatile liquid are especially suited for excretion by the respiratory system. The rate of respiratory excretion is dependent on factors that affect gas​ exchange, including​ diffusion, gas​ solubility, and blood flow to the lungs. Respiratory excretion is not dependent upon​ water-solubility of the drug. Transport proteins are involved with movement of some drugs to their target​ cells, but are not involved with respiratory excretion.

A client reports feeling lightheaded and dizzy a few hours after taking an antihypertensive medication. Which classification of medication should the nurse realize the client has been​ prescribed?

A.
Prodrug
B.
​First-pass
C.
Enzyme inducer
D.
Enzyme inhibitor

A.
Prodrug

Medications that require metabolism to produce therapeutic action are called prodrugs. Because the medication needs to be​ converted, effects of the medication will occur hours later.​ First-pass explains how a drug is metabolized in the liver. Enzyme inducers or enzyme inhibitors would not cause increased symptoms hours after the medication has been administered.

A client is prescribed a​ water-soluble drug. In which body fluid should the nurse expect this medication to be​ excreted? (Select all that​ apply.)

A.
Sweat
B.
Saliva
C.
Urine
D.
Tears
E.
Breastmilk

B. Saliva
C. Urine
E. Breastmilk

A client who is taking phenobarbital as prescribed has a low blood level of the drug. Which factor should the nurse suspect as the reason for this​ finding?

A.
The CYP450 enzyme is unable to metabolize phenobarbital.
B.
Phenobarbital undergoes CYP450 inhibition.
C.
Phenobarbital accelerates its own​ metabolism, requiring increased doses.
D.
Phenobarbital is a​ prodrug, so it may take longer to see a change in drug levels.

C.
Phenobarbital accelerates its own​ metabolism, requiring increased doses.

Phenobarbital is an enzyme inducer and increases the rate of its own destruction. Because medications will be inactivated at a much faster​ rate, higher doses may be required to achieve an optimal therapeutic effect for some clients. Phenobarbital does not undergo CYP450 inhibition and is not a prodrug. This is not occurring because the CYP450 enzyme is unable to metabolize phenobarbital.

The nurse notices that the response of a medication varies among clients. Which client factor should the nurse identify that affects drug​ metabolism? (Select all that​ apply.)

A.
Gender
B.
Neurological impairment
C.
Liver disease
D.
Race
E.
Age

C.
Liver Disease
E.
Age

The nurse reviews serum drug levels for a client. Which level should be identified as optimum for the​ client?

A.
The level between therapeutic effects and adverse effects
B.
The level where adverse effects occur
C.
The level where the drug is not detected in the blood stream
D.
The level where therapeutic effects occur

A.
The level between therapeutic effects and adverse effects

The plasma drug concentration between the minimum effective concentration and the toxic concentration is called the therapeutic range of the drug. This is considered optimum for the client. The toxic concentration is the drug level that will cause serious adverse effects. The minimum effective concentration is the drug level that will cause therapeutic effects.​ Half-life is the level where the drug is no longer detected in the blood stream.

A client asks how long a dose of pain medication will last. Which variable should the nurse review with the​ client? (Select all that​ apply.)

A.
Dosage
B.
Time of day
C.
Client age
D.
​Drug-food interactions
E.
Route of administration

A.
Dosage
D.
​Drug-food interactions
E.
Route of administration

Many variables can affect the duration of drug​ action, including drug​ concentration, dosage, route of drug​ administration,
drug-food
​interactions,
drug-supplement
​interactions,
drug-​herbal,
and
drug-drug
interactions. Client age and time of day do not affect the duration of drug action.

The nurse is administering a medication to a client with a​ half-life of 1 hour. In which time frame should the nurse expect the medication to reach a plateau in the​ client's body?

A.
4 hours
B.
1 hour
C.
3 hours
D.
2 hours

A.
4 hours

Few drugs are administered as a single dose. Repeated doses result in an accumulation of drug in the bloodstream.​ Eventually, a plateau will be reached where the level of drug in the plasma is maintained continuously within the therapeutic range. At this​ level, the amount administered has reached equilibrium with the amount of drug being​ eliminated, resulting in the distribution of a continuous therapeutic level of drug to body tissues.​ Theoretically, it takes approximately four​ half-lives to reach this equilibrium. For a drug with a​ half-life of 1​ hour, it will take 4 hours for a plateau to be reached.
Next Question

An older client is concerned about receiving​ "too much" of a medication because another dose was given shortly after a large initial dose. Which response should the nurse make to this​ patient?

A.
​"The large dose was the loading dose which helps your body reach a therapeutic level​ faster."
B.
​"The large dose did not work so it needed to be followed up with another​ dose."
C.
​"The large dose was not effective because of your​ age."
D.
​"The large dose was used to see if you have an allergy to the​ medication."

A?

A loading dose is a higher amount of​ drug, often given only once or twice to​ "prime" the bloodstream with a sufficient level of drug. Before plasma levels can drop back toward​ zero, intermittent maintenance doses are given to keep the plasma drug concentration in the therapeutic range. A maintenance dose was not provided because of the​ client's age. A loading dose is not used to test for a drug allergy. It is unlikely that the loading dose was ineffective however the maintenance dose will ensure a therapeutic blood level is achieved.

A client is prescribed a maintenance dose of a medication after receiving a loading dose. For which reason should the nurse realize the maintenance dose is​ prescribed?

A.
Prevent toxicity
B.
Reach therapeutic range faster
C.
Prevent fluctuations in blood levels
D.
Keep the medication in the therapeutic range

D.
Keep the medication in the therapeutic range

Maintenance doses are given to keep the plasma drug concentration in the therapeutic range. The loading​ dose, not the maintenance​ dose, allows the medication to reach the therapeutic range faster. Maintenance doses do not prevent​ toxicity, nor do they prevent fluctuation in blood levels.
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