Characteristics of alfa-receptor antagonists include all of the following EXCEPT:

Correct Answer: C

Rationale: The correct answer is C: Bronchospasm. Alpha-receptor antagonists typically do not cause bronchospasm as they primarily act on alpha-adrenergic receptors involved in vasoconstriction. A is correct as alpha-blockers reduce peripheral resistance and blood pressure. B is correct as they can reverse the pressor response of epinephrine. D is correct as they can lead to postural hypotension and reflex tachycardia due to vasodilation. In summary, bronchospasm is not a characteristic of alpha-receptor antagonists, making choice C the correct answer.

Correct Answer: A

Rationale: The correct answer is A: Phenobarbital sodium. It is the drug of choice for status epilepticus in infants and children due to its rapid onset of action, effectiveness in controlling seizures, and safety profile. Phenobarbital is a barbiturate that acts as a GABA agonist, enhancing inhibitory neurotransmission. Clonazepam (B) is also effective but may not provide as rapid seizure control. Ethosuximide (C) is indicated for absence seizures, not status epilepticus. Phenytoin (D) is not recommended in infants due to the risk of causing severe adverse effects like cardiac arrhythmias and hypotension.

Correct Answer: B

Rationale: The correct answer is B: Monoamine oxidase A inhibitors. Levodopa should not be given concurrently with MAO-A inhibitors as they can potentiate the effects of levodopa, leading to an increased risk of hypertensive crisis. MAO-A inhibitors inhibit the breakdown of levodopa, causing an accumulation of dopamine in the brain. This combination can result in severe hypertension and other adverse effects. Choice A (Bromocriptine) is incorrect because it is a dopamine agonist that can be used in combination with levodopa for Parkinson's disease treatment. Choice C (Carbidopa) is incorrect because it is often given in combination with levodopa to enhance its effectiveness by preventing its peripheral metabolism. Choice D (Nonselective beta-adrenergic antagonists) is incorrect as they do not have a direct interaction with levodopa.

Correct Answer: B

Rationale: 1. Tramadol has weak mu agonist effects due to its opioid activity. 2. Tramadol inhibits norepinephrine and serotonin reuptake, enhancing their effects. 3. Loperamide is an opioid receptor agonist with no effect on neurotransmitter reuptake. 4. Fluoxetine is a selective serotonin reuptake inhibitor, not affecting mu receptors. 5. Butorphanol is a kappa-opioid receptor agonist, not a mu agonist like Tramadol.

Correct Answer: A

Rationale: Clozapine is the correct answer because it has high affinity for both D4 and 5-HT2 receptors. Clozapine's unique pharmacological profile contributes to its effectiveness in treating refractory schizophrenia. Fluphenazine, Thioridazine, and Haloperidol do not have as high affinity for both D4 and 5-HT2 receptors, making them less effective in managing symptoms associated with schizophrenia.