Indicate the drug, which is a direct-acting both alfa- and beta-receptor agonist:

Correct Answer: A

Rationale: The correct answer is A: Norepinephrine. Norepinephrine is a direct-acting alpha-1 and beta-1 receptor agonist. It stimulates both alpha and beta receptors directly, leading to vasoconstriction (via alpha-1) and increased heart rate and contractility (via beta-1). Methoxamine (B) is a selective alpha-1 agonist, Isoproterenol (C) is a non-selective beta agonist, and Ephedrine (D) is a mixed-acting sympathomimetic drug with indirect effects. Therefore, norepinephrine is the only choice that directly acts on both alpha and beta receptors.

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: C

Rationale: The correct answer is C, Lamotrigine. Lamotrigine is a phenyltriazine derivative, making it the antiseizure drug in the list. This drug works by stabilizing neuronal membranes and inhibiting voltage-gated sodium channels. Phenobarbital (A) is a barbiturate, Clonazepam (B) is a benzodiazepine, and Carbamazepine (D) is an iminostilbene derivative, not a phenyltriazine derivative like Lamotrigine.

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.