The most common dose-related adverse effects of carbamazepine are:

Correct Answer: A

Rationale: The correct answer is A. Carbamazepine is an antiepileptic drug known to cause dose-related adverse effects such as diplopia (double vision), ataxia (lack of coordination), and nausea. Diplopia and ataxia are common neurological side effects, while nausea is a gastrointestinal side effect. This is due to the drug's mechanism of action on sodium channels in the nervous system. Choices B, C, and D are incorrect. Gingival hyperplasia and hirsutism are not common adverse effects of carbamazepine. Sedation and dependence are more associated with benzodiazepines, and hemeralopia and myasthenic syndrome are not typically linked to carbamazepine use.

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: B

Rationale: Rationale for Choice B (Hyperactive dopaminergic state in the presence of dopamine blockers): 1. Dopamine blockers disrupt the balance of dopamine in the brain. 2. Dopamine blockers lead to an increase in dopamine receptor activity. 3. Hyperactive dopaminergic state causes abnormal movements seen in tardive dyskinesia. 4. This choice directly correlates with the pathophysiology of tardive dyskinesia. Summary of why other choices are incorrect: A: Degeneration of dopaminergic and cholinergic fibers - Tardive dyskinesia is not primarily caused by degeneration of these fibers. C: Degeneration of histaminergic fibers - Histaminergic fibers are not implicated in the development of tardive dyskinesia. D: Supersensitivity of cholinergic receptors in the caudate-putamen - While cholinergic dysfunction is involved, it is not the primary cause of tardive dyskinesia.

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.