Although the benzodiazepines continue to be the agents of choice for insomnia they have:

Correct Answer: D

Rationale: The correct answer is D because benzodiazepines, while effective for insomnia, have the potential for psychological and physiological dependence (A), can cause synergistic depression of the central nervous system when combined with other drugs like alcohol (B), and may result in residual drowsiness and daytime sedation (C). Each of these factors poses risks and side effects associated with the use of benzodiazepines for treating insomnia. Therefore, the answer choice D, which includes all of the above factors, is the correct choice.

Correct Answer: A

Rationale: The correct answer is A: The midbrain periaqueductal gray. This structure plays a crucial role in pain modulation by sending inhibitory signals to the spinal cord. It contains opioid receptors that can reduce pain perception. The hypothalamus (B) is more involved in regulating body functions, the area postrema (C) is primarily responsible for inducing vomiting in response to toxins, and the limbic cortex (D) is associated with emotions and memory, not specifically pain modulation.

Correct Answer: C

Rationale: The correct answer is C: Butorphanol. Non-narcotic analgesics are medications that relieve pain without producing narcotic effects. Butorphanol is a narcotic analgesic, not a non-narcotic one. Paracetamol (A), Acetylsalicylic acid (B), and Ketorolac (D) are all non-narcotic analgesics commonly used for pain relief without causing narcotic effects. Therefore, the incorrect options are A, B, and D because they are non-narcotic analgesics, unlike Butorphanol.

Correct Answer: D

Rationale: The correct answer is D: Lithium carbonate. Lithium is the drug of choice for manic-depressive psychosis (now known as bipolar disorder) due to its mood-stabilizing properties. It helps to reduce the frequency and severity of manic episodes. Imipramine (A) is a tricyclic antidepressant, not typically used for bipolar disorder. Chlordiazepoxide (B) is a benzodiazepine used for anxiety and alcohol withdrawal, not for bipolar disorder. Isocarboxazid (C) is a monoamine oxidase inhibitor used for depression, not specifically for bipolar disorder. In summary, lithium is the preferred treatment for bipolar disorder due to its proven efficacy in managing manic episodes.

Correct Answer: B

Rationale: The correct answer is B: Eleuterococci's extract. This plant origin drug is known for its adaptogenic properties, which help increase overall tone and resilience in the body. Eleuterococci, also known as Siberian ginseng, is used to combat stress and boost energy levels. Meridil (A) is a synthetic drug with unknown effects on tone. Pantocrin (C) is a hormone derived from animal glands, not a plant origin drug. Caffeine (D) is a stimulant that may increase alertness but does not have the same generalized tone-increasing properties as Eleuterococci's extract.