Indicate the local anesthetic, which is used for spinal anesthesia:

Correct Answer: C

Rationale: The correct answer is C: Bupivacaine. Bupivacaine is used for spinal anesthesia due to its long duration of action and potency. It provides effective anesthesia for surgeries and pain management. Procaine (A) is not commonly used for spinal anesthesia due to its short duration of action. Lidocaine (B) is used more for regional anesthesia and nerve blocks. Dupivacaine (D) is a duplicate choice and not a valid option. In summary, bupivacaine is the preferred choice for spinal anesthesia due to its duration of action and efficacy.

Correct Answer: B

Rationale: The correct answer is B: A decrease in intraocular pressure. Depolarizing blockade, such as with succinylcholine, leads to sustained depolarization of the neuromuscular junction, causing muscle paralysis. This can result in hyperkalemia due to potassium release from muscles, emesis due to stimulation of chemoreceptors, and muscle pain due to fasciculations. Intraocular pressure is not affected by depolarizing blockade. Therefore, a decrease in intraocular pressure is not an effect seen with depolarizing blockade, making choice B the correct answer.

Correct Answer: A

Rationale: Step 1: Identify the key difference between epinephrine and ephedrine - epinephrine is a direct-acting sympathomimetic. Step 2: Ephedrine is a mixed-acting sympathomimetic, acting indirectly by releasing norepinephrine from nerve terminals. Step 3: Therefore, the correct answer is A because ephedrine is not a direct-acting sympathomimetic like epinephrine. Summary: B is incorrect because ephedrine does have oral activity, C is incorrect as ephedrine is not resistant to MAO and has a shorter duration of action, and D is incorrect as ephedrine is less potent than epinephrine.

Correct Answer: A

Rationale: Rationale: Betaxolol is the correct answer as it is a beta1-selective antagonist with a long duration of action due to its lipophilic properties. It has minimal beta2 or intrinsic sympathomimetic activity, leading to prolonged effects on heart rate and blood pressure. Sotalol (B) is a non-selective beta-blocker with class III antiarrhythmic properties. Nadolol (C) is a non-selective beta-blocker with a long duration, but not beta1-selective. Metoprolol (D) is a beta1-selective antagonist but has a shorter duration compared to betaxolol.

Correct Answer: D

Rationale: Step 1: Zolpidem is a sedative-hypnotic medication used for treating insomnia by enhancing the effects of GABA in the brain. Step 2: Zolpidem causes significant effects on sleep patterns, not minor ones, making option A incorrect. Step 3: Zolpidem has a lower risk of tolerance and dependence compared to benzodiazepines, making option B correct. Step 4: Zolpidem primarily acts as a sedative and does not have significant muscle relaxing or anticonvulsant effects, making option C incorrect. Step 5: Combining the above points, option D is correct as it encompasses the accurate statements about zolpidem.