The nurse is preparing to administer morning medications to a patient who has been newly diagnosed with tuberculosis. The patient asks, “Why do I have to take so many different drugs?” Which response by the nurse is correct?

Correct Answer: B

Rationale: The correct answer is B: "Taking multiple drugs reduces the chance that the tuberculosis will become drug resistant." Rationale: 1. Combination therapy is essential in treating tuberculosis to prevent the development of drug resistance. 2. Different drugs target various stages of the tuberculosis bacteria's life cycle, reducing the likelihood of resistance. 3. Using a single drug can lead to the bacteria adapting and becoming resistant, making treatment ineffective. 4. Option A is incorrect because relying on just one drug is not effective in preventing drug resistance. 5. Option C is incorrect as using multiple drugs does not necessarily reduce side effects; it primarily aims to prevent resistance. 6. Option D is incorrect because the main goal of using multiple drugs is not to enhance the effect of each drug but to prevent drug resistance.

Correct Answer: C

Rationale: The correct answer is C: Lipophylic group. Local anesthetics exert their potency and toxicity by interacting with sodium channels in nerve fibers. The lipophilic group determines the lipid solubility of the anesthetic, affecting its ability to penetrate nerve membranes and block sodium channels. Ionizable groups are responsible for the drug's pH-dependent solubility and onset of action, while the intermediate chain contributes to the drug's duration of action. Choice D is incorrect because not all components (ionizable group and intermediate chain) solely determine potency and toxicity of local anesthetics.

Correct Answer: C

Rationale: Parasympathomimetic drugs mimic the effects of the parasympathetic nervous system. Stimulation of the parasympathetic system leads to a decrease in heart rate (bradycardia). This is why choice C is correct. Bronchodilation (A) is caused by sympathetic stimulation, mydriasis (B) is caused by sympathetic stimulation, and constipation (D) can be caused by anticholinergic drugs, which have the opposite effect of parasympathomimetic drugs.

Correct Answer: B

Rationale: Step-by-step rationale: 1. Ipratropium is a bronchodilator used in asthma. 2. It works by blocking muscarinic receptors, reducing bronchoconstriction. 3. Atropine and Homatropine are anticholinergic drugs but not commonly used in asthma. 4. Lobeline is a respiratory stimulant, not used for bronchodilation in asthma. Summary: Ipratropium is the correct choice as it specifically targets bronchodilation in asthma by blocking muscarinic receptors. Atropine, Homatropine, and Lobeline are not commonly used for this purpose in asthma treatment.

Correct Answer: A

Rationale: The correct answer is A because alpha agonists cause mydriasis (pupil dilation), not miosis (pupil constriction). Alpha agonists like phenylephrine work by stimulating alpha receptors in the iris dilator muscle, leading to pupil dilation. Therefore, choice A is incorrect. Choices B, C, and D are incorrect because alpha agonists do cause mydriasis, beta antagonists do decrease the production of aqueous humor, and alpha agonists do increase the outflow of aqueous humor from the eye, respectively.