Ganglion blocking drugs are used for the following emergencies EXCEPT:

Correct Answer: C

Rationale: The correct answer is C: Cardiovascular collapse. Ganglion blocking drugs are not used for cardiovascular collapse because they can worsen the condition by further reducing blood pressure. These drugs are indicated for hypertensive crises, controlled hypotension, and pulmonary edema due to their ability to block ganglionic transmission and lower blood pressure. In cardiovascular collapse, the priority is to increase blood pressure and perfusion, which is not achieved by using ganglion blocking drugs. Therefore, using these drugs in cardiovascular collapse can be detrimental. Choices A, B, and D are incorrect because ganglion blocking drugs can be beneficial in managing hypertensive crises, controlled hypotension, and pulmonary edema, respectively.

Correct Answer: B

Rationale: The correct answer is B: Bradycardia. Phentolamine is an alpha-adrenergic blocker, which typically causes tachycardia rather than bradycardia due to its vasodilatory effect. Diarrhea (choice A) can occur due to its effect on smooth muscle relaxation, arrhythmias (choice C) can result from its impact on cardiac conduction, and myocardial ischemia (choice D) can happen due to decreased cardiac output. Bradycardia is not a common adverse effect of phentolamine, making it the correct answer in this scenario.

Correct Answer: B

Rationale: The correct answer is B because imidazopyridines are known to be selective agonists of the BZ1 (omega1) subtype of BZ receptors. This is based on their specific binding affinity and activity at the BZ1 receptor subtype, which distinguishes them from other receptor subtypes. Imidazopyridines do not act as partial agonists at brain 5-TH1A receptors (choice A), competitive antagonists of BZ receptors (choice C), or nonselective agonists of both BZ1 and BZ2 receptor subtypes (choice D). By being selective agonists of the BZ1 subtype, imidazopyridines exhibit unique pharmacological properties that make them suitable for targeting specific therapeutic outcomes related to the BZ1 receptor subtype.

Correct Answer: C

Rationale: The correct answer is C: Vigabatrin. Vigabatrin irreversibly inhibits GABA-T by irreversibly binding to its active site, leading to a sustained increase in GABA levels. This results in enhanced GABAergic neurotransmission. Diazepam (A) and Phenobarbital (B) are not inhibitors of GABA-T. Felbamate (D) acts by blocking NMDA receptors and enhancing GABAergic transmission, but it does not directly inhibit GABA-T.

Correct Answer: D

Rationale: The correct answer is D: Amantadine. Amantadine is an antiviral agent used in the prophylaxis of influenza A2 by inhibiting the viral replication process. Selegiline (A) is a monoamine oxidase inhibitor used in Parkinson's treatment. Sinemet (B) is a combination of carbidopa and levodopa for Parkinson's symptoms. Pergolide (C) is a dopamine agonist used in Parkinson's disease but has been withdrawn due to side effects. Amantadine is the only antiparkinsonian drug in the list with antiviral properties specifically used for influenza A2.