The patient's prescriber has ordered antibiotic combination ...

[joesmith1212]

The patient's prescriber has ordered antibiotic combination therapy. The patient asks the nurse why two antibiotics are required. Which response by the nurse best describes the rationale for combination therapy?
 
  a. Additional coverage is provided in case one of the antibiotics is ineffective.
  b. The first antibiotic potentiates the effect of the second antibiotic.
  c. This is the only effective treatment for fever of unknown origin.
  d. An allergic response is less likely if two antibiotics are administered.

Question 2

The nurse, who is teaching a pharmacology refresher course to a group of nurses, is discussing selective toxicity, which refers to a drug's ability to
 
  a. harm a broad spectrum of organisms.
  b. kill or injure a target organism without injuring the host.
  c. disrupt the mammalian cell wall by causing engorgement and lysis.
  d. increase the production of folic acid used in the synthesis of nucleic acids.

[Cheesycrackers]

Answer to Question 1

ANS: B
The best rationale for combination therapy is that some drugs, when given concurrently, have a potentiative interaction; that is, one given with the other has a greater effect than either given alone.
If an antibiotic is ineffective, it should be replaced by the second antibiotic, not administered concurrently.
Fever of unknown origin does not necessarily require two different antibiotics.
The risk of allergic response would be increased, not decreased, with two antibiotics.

Answer to Question 2

ANS: B
Selective toxicity is the ability of a drug to kill or injure a target organism without injuring the host or other cells or organisms in intimate contact with the target.
A broad-spectrum antibiotic has the ability to harm a broad spectrum of organisms.
Disruption of the mammalian cell wall through engorgement and lysis is known as indiscriminate destruction of the cell.
Selective toxicity does not increase the production of folic acid used in the synthesis of nucleic acids. Bacteria produce the folic acid.