Which of the following opioid analgesics is a strong kappa receptor agonist and a mu receptor antagonist?

Correct Answer: C

Rationale: Rationale: 1. Nalbuphine is a strong kappa receptor agonist: It primarily activates kappa receptors, providing analgesia. 2. Nalbuphine is a mu receptor antagonist: It blocks mu receptors, reducing the risk of mu receptor-associated side effects. 3. Naltrexone (A) is a mu receptor antagonist but not a kappa agonist. 4. Methadone (B) is a mu receptor agonist and NMDA receptor antagonist. 5. Buprenorphine (D) is a partial mu receptor agonist and kappa receptor agonist, not a mu antagonist like nalbuphine.

Correct Answer: C

Rationale: Rationale: Choice C is correct because fluoxetine has minimal binding to cholinergic, histaminic, and alpha-adrenergic receptors, reducing the likelihood of adverse effects compared to drugs that bind strongly to these receptors. Choices A and B are incorrect because fluoxetine specifically inhibits serotonin reuptake, not norepinephrine, and it does not deplete neurotransmitter stores. Choice D is incorrect because not all the statements in A and B are true for fluoxetine.

Correct Answer: B

Rationale: Step-by-step rationale: 1. Anxiolytic agents are specifically designed to reduce anxiety and induce a calming effect. 2. They work by targeting neurotransmitters in the brain to alleviate feelings of anxiety. 3. Anxiolytics do not have analgesic properties, so they do not relieve pain (Choice A). 4. Anxiolytics are not indicated for improving mood in patients with psychotic symptoms (Choice C). 5. Anxiolytics aim to reduce anxiety without causing drowsiness or promoting sleep (Choice D). In summary, the correct answer is B because anxiolytic agents are intended to reduce anxiety and provide a calming effect, while the other choices are incorrect based on the specific pharmacological actions of anxiolytics.

Correct Answer: D

Rationale: The correct answer is D, "All of the above." LSD produces mood swings due to its impact on serotonin levels. It impairs memory, thinking, and judgment by affecting the brain's cognitive functions. LSD also causes perceptual distortions by altering sensory perceptions. Therefore, all choices A, B, and C are correct effects of LSD.

Correct Answer: A

Rationale: The correct answer is A because theophyllines are bronchodilators that help relax the muscles in the airways, making it easier to breathe. By preventing airway constriction, theophyllines can indeed help prevent night asthmatic attacks. Choice B is incorrect because the statement is true. Choice C is incorrect because not all options are correct - only option A is. Choice D is incorrect because the statement is true.