A patient is taking guaifenesin (Humibid) as part of treatment for a sinus infection. Which instruction will the nurse include during patient teaching?

Correct Answer: A

Rationale: The correct answer is A: Force fluids to help loosen and liquefy secretions. Guaifenesin is an expectorant that works by thinning and loosening mucus in the airways, making it easier to cough up secretions. By instructing the patient to increase fluid intake, it helps enhance the medication's effect by keeping the secretions moist and easier to expel. Reporting clear-colored sputum (choice B) is not necessary as it is a normal sign of the medication working. Avoiding driving or operating heavy machinery (choice C) is not relevant as guaifenesin does not have sedating effects. Reporting symptoms lasting longer than 2 days (choice D) is important, but not directly related to the medication's mechanism of action.

Correct Answer: B

Rationale: The correct answer is B: Cumulative effect. Continuous or repeated intake of a drug can lead to the accumulation of the drug in the body, causing a higher concentration than intended, leading to toxic reactions. Refractoriness (A) refers to decreased response to a drug over time. Tolerance (C) is the need for higher doses to achieve the same effect, not necessarily leading to toxicity. Tachyphylaxis (D) is a rapid decrease in response to a drug with repeated administration, not directly related to toxicity.

Correct Answer: D

Rationale: The correct answer is D because a vasoconstrictor actually enhances the effects of a local anesthetic by reducing its uptake by the surrounding nerves. This helps to prolong the duration of action of the anesthetic. Choices A and B are incorrect because a vasoconstrictor can retard drug removal from the injection site, which can increase the chance of toxicity. Choice C is incorrect because a vasoconstrictor actually decreases blood levels by constricting blood vessels at the site of administration, which can lead to localized effects.

Correct Answer: D

Rationale: The correct answer is D because ganglion-blockers (A) and neuromuscular junction blockers (C) both belong to the group of nicotinic receptor-blocking drugs. Ganglion-blockers act on nicotinic receptors in autonomic ganglia, while neuromuscular junction blockers act on nicotinic receptors at the neuromuscular junction. Atropine-similar drugs (B) do not directly block nicotinic receptors, so they are not part of this particular group of drugs. Therefore, choices A and C cover all the drugs that block nicotinic receptors, making D the correct answer.

Correct Answer: D

Rationale: The correct answer is D: Diaphragm. The diaphragm is more resistant to block and recovers rapidly due to its involuntary nature and vital role in breathing. The diaphragm contracts and relaxes continuously, making it more resilient compared to voluntary muscles like the hand, leg, and neck. The other choices are incorrect because voluntary muscles are more susceptible to fatigue and blockage due to their reliance on conscious control and are not essential for immediate survival like the diaphragm.