The nurse is assessing a patient for contraindications to drug therapy with acetaminophen (Tylenol). Which patient should not receive acetaminophen?

Correct Answer: C

Rationale: The correct answer is C because acetaminophen is primarily metabolized in the liver. Patients with a history of liver disease may have impaired liver function, leading to decreased metabolism of acetaminophen and potential toxicity. Fever and headache are common indications for acetaminophen use and do not necessarily contraindicate its use. Peptic ulcer disease is not a contraindication for acetaminophen as it does not directly affect the gastrointestinal system.

Correct Answer: D

Rationale: The correct answer is D because when administering heparin subcutaneously, using a - to -inch 25- to 28-gauge needle is appropriate to ensure proper delivery into the subcutaneous tissue. This needle size is suitable for subcutaneous injections and helps prevent complications such as leakage or irritation. As for the other choices: A: Aspirating the syringe before injecting the medication is not necessary for subcutaneous injections as it is commonly done for intramuscular injections to ensure proper needle placement. B: Massaging the site after injection is not recommended as it can cause bruising or discomfort. C: Applying heat to the injection site is not a standard procedure for subcutaneous injections and may not provide any benefit in this context.

Correct Answer: C

Rationale: The correct answer is C: Obtain an order for a spacer device. This intervention is most appropriate as a spacer device can help improve the delivery of medication from the MDI, even if the patient is unable to coordinate inhalation with activation. The spacer device acts as an intermediary between the inhaler and the patient, allowing the medication to be inhaled more effectively. This ensures that the patient receives the full dose of the medication. Incorrect answers: A: Notifying the doctor that the patient is unable to use the MDI does not directly address the issue of coordination and does not provide a solution. B: Obtaining an order for a peak flow meter is not the most appropriate intervention in this scenario, as it does not address the patient's inability to coordinate the use of the MDI. D: Asking the prescriber if the medication can be given orally is not necessary if the patient can still benefit from using the MDI with the help of a spacer device.

Correct Answer: A

Rationale: Microsomal oxidation is primarily mediated by cytochrome P450 enzymes located in the endoplasmic reticulum of hepatocytes. Lipid-soluble drugs can easily penetrate cell membranes to reach the microsomes where cytochrome P450 enzymes are located, making microsomal oxidation most prominent for lipid-soluble drugs. Water-soluble drugs have limited access to microsomes, reducing the likelihood of undergoing significant microsomal oxidation. Low molecular weight drugs are generally more likely to be lipid-soluble and undergo microsomal oxidation, while high molecular weight drugs may be too large to efficiently access microsomes for this metabolic pathway. Therefore, the correct choice is A: Lipid soluble.

Correct Answer: A

Rationale: The correct answer is A. Chemical antagonism refers to the interaction between two drugs where they combine to form an inactive compound. This results in a decrease in the overall pharmacological effect of the drugs. In contrast, options B, C, and D are incorrect because they describe scenarios where the combination of drugs leads to a more active, more water-soluble, or more fat-soluble compound, which would typically result in enhanced pharmacological effects rather than antagonism.