Drugs that may cause contraceptive failure include:

Correct Answer: B

Rationale: Choice B is correct because carbamazepine induces CYP3A4, speeding contraceptive metabolism and risking failure, per pharmacology data. Choice A is incorrect as warfarin doesn't affect contraceptive efficacy. Choice C is wrong because acetaminophen has no such interaction. Choice D is incorrect since only carbamazepine applies.

Correct Answer: D

Rationale: Choice D is correct because Lexicomp offers pediatric dosing, Medline provides research, and PDR includes label data—all valuable for pediatric drug info. Choice A is incorrect alone as it's one source. Choice B is wrong by itself because it's research-focused. Choice C is incorrect solo since PDR is label-specific.

Correct Answer: B

Rationale: Choice B is correct because diphenhydramine is on the Beers Criteria due to anticholinergic risks like confusion and falls in the elderly. Choice A is incorrect as acetaminophen is safe. Choice C is wrong because amoxicillin isn't listed. Choice D is incorrect since only diphenhydramine fits.

Correct Answer: D

Rationale: Choice D is correct because generics lower costs, tablet splitting (when safe) reduces per-dose expense, and mail-order pharmacies offer discounts—all proven savings methods. Choice A is incorrect alone as it's one strategy. Choice B is wrong by itself because splitting is just part. Choice C is incorrect solo since mail-order is only one option.

Correct Answer: B

Rationale: Choice B is correct because amoxicillin is a prescription antibiotic due to resistance and safety concerns, unlike OTC options. Choice A is incorrect as acetaminophen is OTC. Choice C is wrong because ibuprofen is OTC. Choice D is incorrect since only amoxicillin requires a prescription.