Which one of the following statements about the use of triazolam in an elderly patient is accurate?

Correct Answer: D

Rationale: The correct answer is D) She may experience amnesia, especially if she also drinks alcoholic beverages. Explanation: Triazolam is a short-acting benzodiazepine commonly used for insomnia in the elderly. Elderly patients are more sensitive to the effects of benzodiazepines due to age-related changes in drug metabolism and clearance. When combined with alcohol, which also affects cognitive function and memory, the risk of amnesia is significantly increased. This interaction can lead to falls, injuries, and other adverse events in the elderly population. Why the others are wrong: A) Ambulatory dysfunction can occur in elderly patients even at reduced doses due to the increased sensitivity to benzodiazepines. B) Hypotension, not hypertension, is a common adverse effect of benzodiazepines in the elderly due to their potential to cause sedation and dizziness. C) Over-the-counter cold medications are more likely to potentiate the sedative effects of triazolam rather than antagonize its hypnotic effects. Educational context: Understanding the pharmacokinetics and pharmacodynamics of CNS drugs in the elderly is crucial for healthcare professionals to provide safe and effective care to this vulnerable population. Educating healthcare providers about the risks associated with benzodiazepine use in the elderly, particularly when combined with other CNS depressants like alcohol, can help prevent adverse drug events and improve patient outcomes.

Correct Answer: A

Rationale: The correct answer is A) Useful in anesthesia due to lack of cardiovascular depression. Nitrous oxide is a commonly used anesthetic in clinical practice. This gas is attractive for anesthesia due to its favorable properties such as rapid onset, non-irritant to the respiratory tract, and lack of cardiovascular depression. Its mechanism of action involves NMDA receptor antagonism and modulation of GABA receptors. Option B is incorrect because megaloblastic anemia is associated with prolonged exposure to nitrous oxide, usually after several hours of administration, not just a 2-hour exposure. Option C is incorrect as nitrous oxide is not the most potent inhaled anesthetic. It is less potent compared to other inhaled anesthetics like halothane or isoflurane. Option D is incorrect because malignant hyperthermia is commonly associated with volatile anesthetics like halothane or succinylcholine, not nitrous oxide. In an educational context, understanding the properties and effects of different anesthetics is crucial for healthcare professionals involved in anesthesia administration. Knowing the specific characteristics of nitrous oxide, including its advantages and potential side effects, helps in making informed decisions regarding its use in clinical settings.

Correct Answer: D

Rationale: In this question, the correct answer is D) 80 mg. To understand why, we need to first grasp the concept of a percentage solution. A 2% solution means there are 2 grams of lidocaine in 100 mL of solution. This translates to 20 mg of lidocaine in 1 mL of the solution. Therefore, in a 4 mL vial of the 2% lidocaine solution, there would be 4 * 20 = 80 mg of lidocaine. This calculation is crucial for healthcare professionals as it ensures accurate dosing and administration of medications to patients. Now, let's analyze why the other options are incorrect: A) 2 mg - This is incorrect because, as calculated earlier, there are 20 mg of lidocaine in 1 mL of the solution, not 2 mg. B) 8 mg - This option is incorrect as it does not consider the concentration of the lidocaine solution. It underestimates the amount of lidocaine present in 1 mL. C) 20 mg - While this seems plausible as the concentration of lidocaine in 1 mL, the question specifically asks for the amount present in 1 mL of the 4 mL vial, which contains a total of 80 mg. Understanding medication concentrations is crucial in healthcare to prevent medication errors and ensure patient safety. Healthcare providers must accurately calculate and understand drug concentrations to deliver optimal care.

Correct Answer: D

Rationale: The correct answer is D) Diazepam. Diazepam is a benzodiazepine with spasmolytic activity, making it effective in managing seizures caused by an overdose of local anesthetics. In cases of local anesthetic toxicity, seizures can occur due to the drug's effect on the central nervous system. Diazepam acts as a GABA receptor agonist, exerting its anticonvulsant effects by enhancing inhibitory neurotransmission. Option A) Baclofen is a GABA-B receptor agonist primarily used as a muscle relaxant for spasticity, but it does not possess significant anticonvulsant properties. Option B) Cyclobenzaprine is a muscle relaxant that acts centrally on the brainstem, with no significant anticonvulsant activity. Option C) Dantrolene is a direct-acting muscle relaxant that works by inhibiting calcium release from the sarcoplasmic reticulum in skeletal muscle, and it is not typically used for managing seizures. Educationally, understanding the pharmacological properties of CNS drugs is crucial for healthcare professionals in selecting appropriate agents for specific conditions. Knowledge of the mechanisms of action of different drug classes helps in making informed decisions regarding drug therapy, especially in critical situations such as managing drug toxicities and seizures.

Correct Answer: B

Rationale: The correct answer is B) Decreases formation of 3-O-methyldopa. Tolcapone is a catechol-O-methyltransferase (COMT) inhibitor, which works by blocking the enzyme responsible for the methylation of levodopa to 3-O-methyldopa. By inhibiting this conversion, more levodopa is available to cross the blood-brain barrier and be converted to dopamine in the brain, enhancing its therapeutic effect in Parkinson's disease. Option A is incorrect because Tolcapone inhibits rather than activates COMT. Option C is incorrect as Tolcapone does not inhibit monoamine oxidase type B. Option D is incorrect because Tolcapone does not inhibit dopamine reuptake. In an educational context, understanding the mechanism of action of CNS drugs is crucial for healthcare professionals to make informed decisions in patient care. Knowing how Tolcapone affects the metabolism of levodopa-carbidopa helps in optimizing treatment regimens for patients with Parkinson's disease. This knowledge also aids in minimizing drug interactions and adverse effects, ultimately leading to improved patient outcomes.