Chapter 4- Pharmacotherapeutics
1. In which of the following patients would a nurse expect to experience alterations in drug metabolism?
A) A
... [Show More] 35-year-old woman with cervical cancer
B) A 41-year-old man with kidney stones
C) A 50-year-old man with cirrhosis of the liver
D) A 62-year-old woman in acute renal failure Ans: C
Feedback:
The liver is the most important site for drug metabolism. If the liver is not functioning effectively, as with cirrhosis, drugs will not be metabolized normally and toxic levels could develop. Drug dosage will have to be altered to ensure normal levels in the body. The patient with kidney stones and the patient in acute renal failure would most likely have alterations in drug excretion. If there are no complications with the cervical cancer patient, there should be no alterations in drug therapy.
2. A patient has a blood serum drug level of 50 units/mL. The drug's half-life is 1 hour. If concentrations above 25 units/mL are toxic and no more of the drug is given, how long will it take for the blood level to reach the nontoxic range?
A) 30 minutes
B) 1 hour
C) 2 hours
D) 3 hours
Ans: B
Feedback:
Half-life is the time required for the serum concentration of a drug to decrease by 50%. After 1 hour, the serum concentration would be 25 units/mL (50/2). After 2 hours the serum concentration would be 12.5 units/mL (25/2) and reach the nontoxic range.
3. A nurse has been administering a drug to a patient intramuscularly (IM). The physician discontinued the IM dose and wrote an order for the drug to be given orally. The nurse notices that the oral dosage is considerably higher than the parenteral dose and understands that this due to
A) passive diffusion.
B) active transport.
C) glomerular filtration.
D) first-pass effect.
Ans: D
Feedback:
The first-pass effect involves drugs that are given PO and absorbed from the small intestine directly into the portal venous system, which delivers the drug molecules to the liver. Once in the liver, enzymes break the drug into metabolites; they may become active or may be deactivated and readily excreted from the body. A large percentage of the oral dose is usually destroyed and never reaches tissues. Oral dosages account for this phenomenon to ensure an appropriate amount of the drug in the body to produce a
therapeutic action. Passive diffusion is the major process through which drugs are absorbed into the body. Active transport is a process that uses energy to actively move a molecule across a cell membrane and is often involved in drug excretion in the kidney. Glomerular filtration is the passage of water and water-soluble components from the plasma into the renal tubule.
4. A nurse receives an order to administer a critically ill patient two drugs immediately (stat). The nurse begins the process by
A) washing his or her hands before handling the medications.
B) consulting a drug guide for compatibility.
C) questioning the patient concerning allergies.
D) identifying the patient by checking the armband and asking the patient to state his name.
Ans: B
Feedback:
A nurse should always make sure that two or more drugs can be given at the same time before the administration process is begun. Incompatibility can affect absorption and distribution. Once the nurse is certain that the drugs are compatible, he or she should perform handwashing and prepare the medications for administration. The nurse should also identify the patient appropriately and ask about drug allergies prior to administering the medication. [Show Less]