In the treatment of congenital adrenal hyperplasia in which there is excess production of cortisol precursor, the purpose of administration of synthetic glucocorticoid is:

Correct Answer: D

Rationale: In CAH (choice D), synthetic glucocorticoids suppress ACTH, reducing adrenal precursor excess (e.g., 17-hydroxyprogesterone). Aldosterone (choice A), renal (choice B), and immune (choice C) effects aren't primary goals. ACTH suppression corrects the defect.

Correct Answer: D

Rationale: The signs and symptoms described in the text, such as talkativeness, mydriasis, muscle twitching, hand tremor, elevated blood pressure, and increased heart rate, are consistent with the effects of amphetamine use. Amphetamine is a stimulant drug that can cause these symptoms by increasing the release of neurotransmitters like dopamine and norepinephrine in the brain. Additionally, the patient being a drug user who tried different drugs supports the likelihood of amphetamine use, as it is commonly abused for its stimulant effects.

Correct Answer: D

Rationale: Chloral hydrate (choice D) is metabolized to trichloroethanol, which depresses the CNS, inducing sedation. Morphine (choice A) metabolizes to active compounds like morphine-6-glucuronide, not trichloroethanol. Clorazepate (choice B) becomes desmethyldiazepam, a benzodiazepine. Phenobarbitone (choice C) is a barbiturate, not metabolized to trichloroethanol. This identifies Chloral hydrate's metabolic pathway, key for its hypnotic use.

Correct Answer: C

Rationale: NMDA receptors are crucial for synaptic plasticity and long-term potentiation.

Correct Answer: C

Rationale: These drugs have anticholinergic properties, often causing dry mouth, blurred vision, and sedation due to their atropine-like effects.