Decomposition of acetylsalicylic acid at room temperature most likely occurs by

Correct Answer: C

Rationale: The correct answer is C) Hydrolysis of the ester. Acetylsalicylic acid, commonly known as aspirin, is an ester of salicylic acid and acetic acid. At room temperature, acetylsalicylic acid can undergo hydrolysis, a chemical reaction where water breaks down the ester bond in the molecule. This reaction results in the formation of salicylic acid and acetic acid. Option A) Oxidation of the ester is incorrect because oxidation involves the loss of electrons, which is not the primary mechanism for the decomposition of acetylsalicylic acid at room temperature. Option B) Reduction of the carboxylic acid is incorrect as reduction involves the gain of electrons, which is also not the primary mechanism for the decomposition of acetylsalicylic acid. Educationally, understanding the decomposition of acetylsalicylic acid is crucial in pharmacology as it impacts the stability and efficacy of the drug. Knowing that hydrolysis is the primary process at play can help pharmacists and healthcare professionals ensure proper storage conditions for medications containing acetylsalicylic acid to maintain their potency and effectiveness.

Correct Answer: D

Rationale: In the case of a newborn diagnosed with transposition of the great arteries, the correct drug to keep the ductus arteriosus open is Misoprostol (Option D). Misoprostol is a prostaglandin E1 analog that helps maintain patency of the ductus arteriosus, which is important in cases like transposition of the great arteries where proper mixing of oxygenated and deoxygenated blood is crucial for survival. Now, let's discuss why the other options are incorrect: - Cortisol (Option A): Cortisol is a steroid hormone and is not used to keep the ductus arteriosus open in this scenario. - Indomethacin (Option B): Indomethacin is a nonsteroidal anti-inflammatory drug (NSAID) that actually promotes closure of the ductus arteriosus, which is not desired in this case. - Ketorolac (Option C): Ketorolac is also an NSAID like indomethacin and would have a similar effect of promoting closure of the ductus arteriosus. In an educational context, understanding the pharmacology of drugs used in neonatal cardiac conditions is crucial for healthcare professionals working in neonatal intensive care units. Knowing the specific actions of drugs like Misoprostol in maintaining ductal patency can directly impact patient outcomes in critical situations like transposition of the great arteries. This knowledge helps in making informed clinical decisions and providing optimal care to neonates with complex cardiac conditions.

Correct Answer: B

Rationale: In pharmacology, understanding the adverse effects of medications is crucial for safe prescribing and patient care. In this question, the correct answer is B) Acetaminophen, which is least likely to cause gastric ulceration compared to the other options. Acetaminophen is classified as an analgesic and antipyretic but lacks significant anti-inflammatory properties. Unlike nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin, piroxicam, and meclofenamate, which inhibit cyclooxygenase enzymes leading to decreased prostaglandin synthesis and subsequent gastric irritation, acetaminophen works through different pathways and is less likely to cause gastric ulceration. Aspirin (Option A) is known to cause gastric ulcers due to its effects on the gastric mucosa. Piroxicam (Option C) and meclofenamate (Option D) are NSAIDs associated with a higher risk of gastric ulceration compared to acetaminophen. Educationally, this question highlights the importance of understanding the mechanisms of action of different drug classes and their associated adverse effects. It reinforces the concept that not all pain medications have the same risk profile for causing gastric ulcers, emphasizing the need for individualized treatment plans based on a patient's specific needs and risk factors.

Correct Answer: A

Rationale: The correct answer is A) Methadone. Methadone is a long-acting opioid with a half-life ranging from 8 to 59 hours, making it one of the longest-acting narcotics. This extended duration of action is due to its unique pharmacokinetic properties, including its high lipid solubility and tissue accumulation. Methadone is commonly used for the treatment of chronic pain and opioid dependence due to its sustained effects. Option B) Controlled-release morphine is a long-acting opioid as well, but its duration of action is typically shorter than methadone. It is often used for moderate to severe pain management but does not have the prolonged effect of methadone. Option C) Levorphanol is a potent opioid analgesic with a long duration of action, but it is not as long-acting as methadone. It is used for severe pain management but does not have the same sustained effect as methadone. Option D) Transdermal fentanyl is a potent opioid with a relatively rapid onset of action but a shorter duration compared to methadone. It is commonly used for chronic pain management, particularly in patients who require continuous opioid therapy, but it does not have the prolonged effect of methadone. In an educational context, understanding the duration of action of different narcotics is crucial for healthcare professionals when selecting the most appropriate medication for pain management. Knowledge of the pharmacokinetic properties of opioids helps in optimizing treatment outcomes while minimizing the risk of adverse effects and misuse. Methadone's long duration of action makes it a valuable option in certain clinical scenarios where extended pain relief is needed.

Correct Answer: B

Rationale: The correct answer is B) Platelets cannot synthesize fresh COX molecules. Aspirin irreversibly inhibits cyclooxygenase (COX) enzymes, which are responsible for producing prostaglandins involved in inflammation and platelet aggregation. In low doses, aspirin's inhibition of COX in platelets is long-lasting because platelets lack the ability to synthesize new COX enzymes. Once aspirin acetylates and inactivates the existing COX enzymes in platelets, they cannot regenerate these enzymes, leading to a prolonged antiplatelet effect. Option A) Platelets contain low quantity of COX is incorrect because platelets do contain COX enzymes, albeit in lower quantities compared to other cells. Option C) Platelets bind aspirin with high affinity is incorrect because aspirin binds irreversibly to COX enzymes, not platelets themselves. Option D) Platelet COX is inducible is incorrect because platelet COX is not inducible; once inhibited by aspirin, platelets cannot induce the synthesis of new COX enzymes. Understanding the mechanism of action of aspirin in inhibiting platelet function through COX inhibition is crucial in pharmacology, particularly in the context of cardiovascular diseases where aspirin is commonly used for its antiplatelet effects to reduce the risk of thrombotic events. This knowledge helps healthcare professionals make informed decisions regarding the appropriate use of aspirin therapy in various clinical scenarios.