Indicate adrenoreceptor antagonist agents which are used for the management of pheochromocytoma:

Correct Answer: D

Rationale: The correct answer is D: Αlfa-receptor antagonists. Alpha-receptor antagonists, such as phenoxybenzamine and phentolamine, are used in the management of pheochromocytoma to block the effects of excess catecholamines released by the tumor. These agents help control hypertension and other symptoms associated with pheochromocytoma. A: Selective beta2-receptor antagonists are not typically used in the management of pheochromocytoma because they do not target the alpha-receptors responsible for the symptoms. B: Nonselective beta-receptor antagonists may be used as adjunct therapy in pheochromocytoma to control tachycardia, but they do not directly address the alpha-receptor effects. C: Indirect-acting adrenoreceptor antagonist drugs do not specifically target the alpha-receptors involved in pheochromocytoma symptoms. In summary,

Correct Answer: B

Rationale: The correct answer is B: Inhibition of GABA aminotransferase. Vigabatrin increases GABA levels by inhibiting GABA aminotransferase enzyme, which is responsible for GABA breakdown. This leads to enhanced GABAergic inhibition in the brain. A: Direct action on the GABA receptor-chloride channel complex is incorrect as vigabatrin does not directly bind to GABA receptors. C: NMDA receptor blockade via the glycine binding site is incorrect as vigabatrin does not affect NMDA receptors. D: Inhibition of GABA neuronal reuptake from synapses is incorrect as vigabatrin does not affect GABA reuptake mechanisms.

Correct Answer: C

Rationale: Rationale: 1. Tolcapone inhibits catechol-O-methyltransferase (COMT), reducing levodopa peripheral metabolism. 2. By prolonging levodopa's action, it enhances its efficacy in treating Parkinson's disease. 3. Carbidopa enhances levodopa bioavailability, not directly affecting its peripheral metabolism. 4. Clozapine is an antipsychotic with no COMT inhibitory activity. 5. Rasagiline is a monoamine oxidase-B inhibitor, not a COMT inhibitor.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Alcohol potentiates SNS depressants by enhancing their sedative effects, vasodilators by causing further relaxation of blood vessels, and hypoglycemic agents by lowering blood sugar levels. This occurs due to alcohol's ability to enhance the effects of these substances, leading to increased sedation, blood vessel dilation, and blood sugar reduction when combined. Therefore, choosing any of the other options would be incorrect as they do not encompass the full range of substances that alcohol can potentiate.

Correct Answer: D

Rationale: Phenothiazine derivatives like chlorpromazine possess antihistaminic, anticholinergic, and antidopaminergic activities. These properties make them effective in treating various conditions like schizophrenia. Antihistaminic activity helps with sedation, anticholinergic activity reduces side effects like tremors, and antidopaminergic activity helps manage psychotic symptoms. Therefore, the correct answer is D. Choices A, B, and C are incorrect because phenothiazines typically exhibit a combination of all three activities, not just one.