Which of the following antidepressants may have latency period as short as 48 hours?

Correct Answer: A

Rationale: The correct answer is A: Tranylcypromine. Tranylcypromine is a monoamine oxidase inhibitor (MAOI) that can rapidly increase synaptic concentrations of neurotransmitters. Due to this mechanism of action, it can have a short latency period of as little as 48 hours. Incorrect answers: B: Imipramine is a tricyclic antidepressant that typically takes 2-4 weeks to show therapeutic effects. C: Fluoxetine is an SSRI that usually takes 2-6 weeks for full efficacy. D: Amitriptyline is a tricyclic antidepressant with a similar latency period to imipramine, typically 2-4 weeks.

Correct Answer: A

Rationale: The correct answer is A: "ecstasy" (methylenedioxymethamphetamine). Ecstasy is related to psychedelics due to its hallucinogenic effects, altering sensory perception and mood. It acts on serotonin receptors, similar to classic psychedelics like LSD. Incorrect choices: B: Cocaine - Cocaine is a stimulant but not related to psychedelics. It primarily affects dopamine levels in the brain. C: "crack" (cocaine free base) - Crack is a form of cocaine, also primarily impacting dopamine levels. D: Caffeine - Caffeine is a stimulant that primarily affects adenosine receptors, not related to psychedelics.

Correct Answer: D

Rationale: Correct Answer: D Rationale: 1. Methylxanthines (e.g., theophylline) help relax bronchial smooth muscles. 2. M-cholinoblocking agents (e.g., ipratropium) block the action of acetylcholine, reducing bronchoconstriction. 3. Beta2-stimulants (e.g., albuterol) relax bronchial smooth muscles and dilate airways. 4. "All of above" encompasses all three drug groups, covering various mechanisms to manage asthma symptoms effectively.

Correct Answer: B

Rationale: Erythropoietin does not influence leucopoiesis because it specifically stimulates the production of red blood cells (erythropoiesis). Filgrastim (A) increases white blood cell production, Doxorubicin (C) suppresses bone marrow function impacting white blood cell production, and Methotrexate (D) inhibits cell proliferation including white blood cells. Therefore, B is the correct answer as it does not affect leucopoiesis.

Correct Answer: B

Rationale: Step-by-step rationale for why B (Dobutamine) is the correct answer: 1. Dobutamine is a selective beta-1 agonist, primarily targeting β1-adrenergic receptors in the heart. 2. It increases cardiac contractility and heart rate, making it useful in treating heart failure and cardiogenic shock. 3. Digoxin (A) is a cardiac glycoside, Amrinone (C) is a phosphodiesterase inhibitor, and Dopamine (D) acts on multiple receptors. 4. Thus, the specific action of dobutamine on beta-1 receptors distinguishes it as the correct choice.