Indicate the indirect-acting adrenoreceptor blocking drug:

Correct Answer: B

Rationale: The correct answer is B, Reserpine, as it inhibits the storage of norepinephrine and other neurotransmitters in vesicles, indirectly blocking adrenoreceptor activation. Tolazoline (A) is a vasodilator, Carvedilol (C) is a non-selective beta-blocker with alpha-blocking activity, and Prazosin (D) is a selective alpha-1 adrenergic receptor antagonist. Reserpine is the only indirect-acting adrenoreceptor blocking drug among the choices provided.

Correct Answer: C

Rationale: Rationale: Carbamazepine is the correct answer because it is a first-line treatment for trigeminal neuralgia due to its mechanism of action in inhibiting voltage-gated sodium channels. This helps reduce neuronal firing and alleviate nerve pain. Primidone and Lamotrigine are not typically used for trigeminal neuralgia. Topiramate may have some efficacy, but it is not as effective as Carbamazepine, which is the drug of choice for treating this condition.

Correct Answer: A

Rationale: The correct answer is A: Pyridoxine. Pyridoxine (Vitamin B6) accelerates the metabolism of levodopa outside the brain, reducing its effectiveness. This leads to decreased levodopa levels in the brain, diminishing its beneficial effects in treating Parkinson's disease. Thiamine (B1), Tocopherol (E), and Riboflavin (B2) do not have this effect on levodopa metabolism.

Correct Answer: B

Rationale: Step 1: Buprenorphine is a partial mu receptor agonist with 20-60 times the analgesic potency of morphine. This is due to its high affinity for the mu receptor, resulting in potent analgesic effects. Step 2: Buprenorphine also has a longer duration of action compared to morphine, making it suitable for sustained pain management. Summary: A: Pentazocine is a mixed opioid receptor agonist/antagonist, not a partial mu receptor agonist like buprenorphine. C: Nalbuphine is a kappa receptor agonist and mu receptor antagonist, not a partial mu receptor agonist like buprenorphine. D: Naltrexone is a pure opioid receptor antagonist, not a partial mu receptor agonist like buprenorphine.

Correct Answer: D

Rationale: Step 1: Atypical antipsychotic agents like clozapine have reduced risks of extrapyramidal system dysfunction and tardive dyskinesia compared to typical ones. Step 2: Atypical antipsychotics have low affinity for D1 and D2 dopamine receptors. Step 3: Atypical antipsychotics have high affinity for D4 dopamine receptors. Therefore, the correct answer is D because all the statements are true for atypical antipsychotic agents like clozapine. Other choices are incorrect because they do not cover all the key differences between atypical and typical antipsychotic agents.