The nurse is reviewing pharmacology terms for a group of newly graduated nurses. Which sentence defines a drug's half-life?
- A. The time it takes for the drug to cause half of its therapeutic response
- B. The time it takes for one half of the original amount of a drug to reach the target cells
- C. The time it takes for one half of the original amount of a drug to be removed from the body
- D. The time it takes for one half of the original amount of a drug to be absorbed into the circulation
Correct Answer: C
Rationale: A drug's half-life is the time it takes for one half of the original amount of a drug to be removed from the body. It is a measure of the rate at which drugs are removed from the body. The other options are incorrect definitions of half-life.
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A drug dose that delivers 10 mg has a half-life of 5 hours. Identify how much drug will remain in the body after one half-life.
Correct Answer: 5 mg
Rationale: A drug's half-life is the time required for one half of an administered dose of a drug to be eliminated by the body, or the time it takes for the blood level of a drug to be reduced by 50%. Therefore, one half of 10 mg equals 5 mg.
When given an intravenous medication, the patient says to the nurse, -I usually take pills. Why does this medication have to be given in the arm? What is the nurse's best answer?
- A. The medication will cause fewer adverse effects when given intravenously.
- B. The intravenous medication will have delayed absorption into the body's tissues.
- C. The action of the medication will begin sooner when given intravenously.
- D. There is a lower chance of allergic reactions when drugs are given intravenously.
Correct Answer: C
Rationale: An intravenous (IV) injection provides the fastest route of absorption. The IV route does not affect the number of adverse effects, nor does it cause delayed tissue absorption (it results in faster absorption). The IV route does not affect the number of allergic reactions.
The nurse is administering parenteral drugs. Which statement is true regarding parenteral drugs?
- A. Parenteral drugs bypass the first-pass effect.
- B. Absorption of parenteral drugs is affected by reduced blood flow to the stomach.
- C. Absorption of parenteral drugs is faster when the stomach is empty.
- D. Parenteral drugs exert their effects while circulating in the bloodstream.
Correct Answer: A
Rationale: Drugs given by the parenteral route bypass the first-pass effect. Reduced blood flow to the stomach and the presence of food in the stomach apply to enteral drugs (taken orally), not to parenteral drugs. Parenteral drugs must be absorbed into cells and tissues from the circulation before they can exert their effects; they do not exert their effects while circulating in the bloodstream.
A patient who has advanced cancer is receiving opioid medications around the clock to keep him comfortable as he nears the end of his life. Which term best describes this type of therapy?
- A. Pallative therapy
- B. Maintenance therapy
- C. Empirric therapy
- D. Supplmental therapy
Correct Answer: A
Rationale: The goal of palliative therapy is to make the patient as comfortable as possible. It is typically used in the end stages of illnesses when all attempts at curative therapy have failed. Maintenance therapy is used for the treatment of chronic illnesses such as hypertension. Empirric therapy is based on clinical probabilities and involves drug administration when a certain pathologic condition has an uncertain but high likelihood of occurrence based on the patient's initial presenting symptoms. Supplemental therapy (or replacement therapy) supplies the body with a substance needed to maintain normal function.
The patient is stating that he has a headache and asks the nurse which over-the-counter medication form would work the fastest to help reduce the pain. Which medication form will the nurse suggest?
- A. A capsule
- B. A tablet
- C. A powder
- D. An enteric-coated tablet
Correct Answer: C
Rationale: Of the types of oral medications listed, the powder form would be absorbed the fastest, thus having a faster onset. The tablet, the capsule, and, finally, the enteric-coated tablet would be absorbed next, in that order.
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