Question

a 62 - year - old man is to receive a new medication to manage his blood pressure. upon assessment, the nurse notes that he has a history of alcoholism and has late - stage liver failure. the nurse will expect which adjustments to his drug therapy?
the dosage will be reduced.
no changes will be made to the patients dosage.
the medication will be changed to an oral form.
an increased dosage will be prescribed.
question 10
the nurse is reviewing a list of a patients medications and notes that one of the drugs is known to have a low (narrow) therapeutic index. which statement accurately explains this concept?
the difference between a therapeutic dose and toxic is large.
the difference between a therapeutic dose and toxic dose is small.
the dose needed to reach a therapeutic level.
the drug only has a slight chance of being effective.

Explanation:

• First question:
• The liver is crucial for drug metabolism. In late - stage liver failure (due to alcoholism in this case), the liver's ability to metabolize drugs is impaired. Reducing the dosage helps prevent drug accumulation and toxicity.
• Second question:
• The therapeutic index (TI) is calculated as \(TI=\frac{TD_{50}}{ED_{50}}\) (where \(TD_{50}\) is the median toxic dose and \(ED_{50}\) is the median effective dose). A low (narrow) therapeutic index means that \(TD_{50}\) is close to \(ED_{50}\), so the difference between the therapeutic dose and the toxic dose is small.

Answer:

• First question: The dosage will be reduced.
• Second question: The difference between a therapeutic dose and toxic dose is small.