Selective COX-2 inhibitors are safer than nonselective COX-1 inhibitors but without loss of efficacy. This consideration is:

Correct Answer: A

Rationale: The correct answer is A: TRUE. Selective COX-2 inhibitors are safer than nonselective COX-1 inhibitors due to reduced risk of gastrointestinal side effects while maintaining efficacy. This is because COX-2 inhibitors target inflammation specifically, sparing COX-1 which is important for gastric mucosal protection. Nonselective COX-1 inhibitors can lead to gastric ulcers and bleeding. The other choices are incorrect: B: FALSE - selective COX-2 inhibitors are indeed safer than nonselective COX-1 inhibitors; C: None - this choice does not provide any information; D: All of the above - this choice is incorrect as only option A is true.

Correct Answer: D

Rationale: Rationale: 1. Vitamin C is known for its antioxidant properties, which help in neutralizing free radicals and protecting cells from damage. 2. It is required for hydroxylation reactions, such as converting proline to hydroxyproline for collagen synthesis, essential for maintaining connective tissues. 3. Vitamin C does not function as pyridoxal phosphate (choice A) or a constituent of coenzyme A (choice B). 4. While vitamin C is involved in one-carbon metabolism, it does not directly act as a carrier of one-carbon groups as described in choice C. Summary: The correct answer (D) highlights the antioxidant properties and the role of vitamin C in hydroxylation reactions for collagen synthesis. Choices A, B, and C are incorrect as they misrepresent the functions of vitamin C.

Correct Answer: D

Rationale: The correct answer is D. Drugs that inhibit cholesterol synthesis, such as statins, do not tend to lengthen the sleep cycle. Statins are not known to have a direct effect on sleep patterns. Choices A, B, and C are true statements regarding drugs inhibiting cholesterol synthesis. Choice A is correct as these drugs are contraindicated in pregnant women and children due to potential harm to fetal development. Choice B is correct as statins can cause myopathy, especially when used with cyclosporine. Choice C is correct as failure to discontinue the drug after myopathy has been detected can lead to acute renal failure.

Correct Answer: B

Rationale: The correct route of administration for vitamin D3 is oral (Choice B) because it is a fat-soluble vitamin that can be effectively absorbed through the digestive system. Subcutaneous (Choice A) and intravenous (Choice C) routes are not typically used for vitamin D3 as it can lead to potential risks and complications. Intranasal (Choice D) administration is not a common route for vitamin D3 absorption, as it may not provide adequate bioavailability compared to oral ingestion. Therefore, the oral route is the most appropriate and efficient method for administering vitamin D3.

Correct Answer: D

Rationale: The correct answer is D: Fractures. Plicamycin is not known to cause fractures. Thrombocytopenia, GI toxicity, and bleeding disorders are potential unwanted effects of plicamycin due to its impact on bone marrow and gastrointestinal tract. It is crucial to recognize that fractures are not a documented side effect of plicamycin, making option D the correct answer.