Which of the following hypnotics is preferred for elderly patients?

Correct Answer: C

Rationale: The correct answer is C: Temazepam. Temazepam is preferred for elderly patients due to its shorter half-life, reduced risk of accumulation, and lower potential for drug interactions compared to other options. Phenobarbital (A) and Secobarbital (D) have long half-lives, leading to increased risk of side effects and drug interactions in the elderly. Flurazepam (B) has a long half-life and can cause residual sedation, increasing the risk of falls and cognitive impairment in the elderly.

Correct Answer: A

Rationale: 1. Selegiline is a monoamine oxidase-B inhibitor that can delay the need for levodopa by inhibiting dopamine breakdown. 2. Studies have shown that selegiline can postpone the need for levodopa by 3-9 months. 3. By delaying levodopa initiation, selegiline may slow down the progression of Parkinson's disease. 4. Therefore, the statement that treatment with selegiline postpones the need for levodopa and may retard disease progression is true. Summary: B is incorrect because evidence supports the efficacy of selegiline in delaying levodopa use. C is incorrect as there is a clear correct answer. D is incorrect as not all options are correct, only option A is supported by evidence.

Correct Answer: A

Rationale: The correct answer is A because moderate alcohol consumption has been shown to raise serum levels of high-density lipoproteins (HDL), also known as "good" cholesterol. HDL helps remove other forms of cholesterol from the bloodstream, reducing the risk of cardiovascular disease. Increased HDL levels are associated with a lower risk of heart disease. On the other hand, choices B, C, and D are incorrect. Choice B, increasing low-density lipoproteins (LDL), is not a typical effect of moderate alcohol consumption and is associated with an increased risk of heart disease. Choice C, decreasing HDL levels, contradicts the known positive effect of alcohol on HDL. Choice D, raising very low-density lipoproteins (VLDL), is not a common result of moderate alcohol intake and is typically associated with an increased risk of heart disease.

Correct Answer: A

Rationale: The correct answer is A because phenothiazine derivatives exert their strong antiemetic effect by blocking dopamine receptors in the chemoreceptor trigger zone of the medulla. This area is responsible for initiating the vomiting reflex. By blocking dopamine receptors here, phenothiazines prevent the activation of the vomiting reflex. Choices B and C are incorrect because phenothiazines primarily target the chemoreceptor trigger zone in the medulla, not the receptors in the stomach or the medullar vomiting centre. Choice D is also incorrect because the antiemetic effect is specifically due to dopamine receptor blockade in the chemoreceptor trigger zone, not all of the above options.

Correct Answer: D

Rationale: The main claim for an ideal antidepressant agent should encompass all aspects mentioned in the choices. A faster onset of action ensures quicker relief for the patient. Fewer adverse effects reduce the burden on the patient. Lower toxicity in overdoses enhances safety. Therefore, D is correct as it combines these essential criteria for an ideal antidepressant. Options A, B, and C individually address important factors but do not cover the comprehensive requirements of an ideal antidepressant, making them incorrect.