A patient with elevated lipid levels has a new prescription for nicotinic acid (niacin). The nurse informs the patient that which adverse effects may occur with this medication?

Correct Answer: A

Rationale: The correct answer is A: Pruritus, cutaneous flushing. Nicotinic acid commonly causes flushing due to prostaglandin release. Pruritus may also occur. B is incorrect as tinnitus and urine odor changes are not associated with nicotinic acid. C is incorrect as myalgia and fatigue are not common adverse effects. D is incorrect as blurred vision and headaches are not typically seen with nicotinic acid use. Therefore, A is the most appropriate choice based on the common adverse effects of nicotinic acid.

Correct Answer: A

Rationale: The correct answer is A because half-life represents the time taken for the concentration of a drug in the plasma to reduce by 50%. This is crucial during the elimination phase when the drug is being cleared from the body. Choice B is incorrect as half-life does not specifically relate to drug metabolism into active metabolites. Choice C is incorrect as half-life is not about drug absorption but elimination. Choice D is incorrect as half-life does not pertain to drug binding to plasma proteins but rather the rate of elimination from the body.

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.