Which is the best description of when drug interactions occur?

Correct Answer: C

Rationale: The correct answer is C because drug interactions occur when one drug alters the effect of another drug by affecting its pharmacokinetic or pharmacodynamic properties. This can lead to either potentiation or reduction of the drug's effects. Choice A is incorrect as toxic dosages do not necessarily lead to drug interactions. Choice B is incorrect as an increase in pharmacodynamics of bound drugs does not necessarily involve interactions with other drugs. Choice D is incorrect because an increase in drug excretion does not directly relate to drug interactions.

Correct Answer: C

Rationale: Rationale: 1. Candida albicans is a type of yeast commonly causing fungal infections. 2. Nystatin is an antifungal medication effective against Candida species. 3. Nystatin works by binding to fungal cell membranes and disrupting their integrity. 4. Griseofulvin (Choice A) is used to treat fungal skin infections, not Candida. 5. Terbinafine (Choice B) is mainly used for dermatophyte infections, not Candida. 6. Caspofungin (Choice D) is more suitable for invasive fungal infections like aspergillosis, not Candida. Summary: - Choice A, B, and D are incorrect because they do not target Candida albicans specifically. - Choice C is correct as nystatin is the appropriate treatment for Candida albicans infections.

Correct Answer: A

Rationale: The correct answer is A: Muscle pain. Statins are known to cause myopathy, a condition characterized by muscle pain or weakness. This is due to statins affecting the production of Coenzyme Q10, which is essential for muscle function. Other choices are incorrect because weight loss is not a common side effect of statins; dizziness is more commonly associated with blood pressure medications or other classes of drugs; and statins are actually used to help lower blood pressure in patients with hypertension, so it is not a common side effect of statins.

Correct Answer: A

Rationale: The correct answer is A because enalapril is an angiotensin-converting enzyme (ACE) inhibitor that works by inhibiting the conversion of angiotensin I to angiotensin II. This leads to vasodilation, decreased aldosterone secretion, and reduced sodium and water retention, ultimately lowering blood pressure. Choices B, C, and D are incorrect because enalapril does not block beta-1 adrenergic receptors, relax vascular smooth muscle directly, or inhibit aldosterone secretion from the adrenal glands.

Correct Answer: A

Rationale: Rationale: 1. Losartan is an angiotensin II receptor blocker, blocking the effects of angiotensin II to lower blood pressure. 2. Lisinopril is an ACE inhibitor, not specifically targeting angiotensin II receptors. 3. Amlodipine is a calcium channel blocker, not directly affecting angiotensin II. 4. Hydrochlorothiazide is a diuretic that works on the kidneys, not angiotensin II receptors.