Principal properties of cordiamine include all of the following EXCEPT:

Correct Answer: D

Rationale: The correct answer is D: Significant abuse potential. Cordiamine is primarily used as a cardiac analeptic, respiratory analeptic, and coronarodilatator, meaning it stimulates cardiac and respiratory functions and dilates coronary blood vessels. There is no evidence or indication that cordiamine has significant abuse potential. It is not a psychoactive substance and does not produce euphoria or addiction. Therefore, option D is the correct answer as it does not align with the principal properties of cordiamine.

Correct Answer: B

Rationale: The correct answer is B: The reflex mechanism. Cytiton acts by triggering a reflex mechanism, which involves a response to a stimulus that is automatic and involuntary. This mechanism is distinct from direct activation of the respiratory center (choice A) or a mixed mechanism (choice C). Choice D is incorrect as Cytiton does have a specific action mechanism. In summary, the correct choice is B because it accurately describes how Cytiton works through a reflex mechanism, while the other choices do not align with the known pharmacological action of Cytiton.

Correct Answer: D

Rationale: The correct answer is D: Sodium phosphate. Osmotic laxatives like sodium phosphate work by drawing water into the colon to soften the stool and stimulate bowel movements. Docusate sodium (A) is a stool softener, not an osmotic laxative. Bisacodyl (B) is a stimulant laxative that works by increasing muscle contractions in the intestines. Phenolphthalein (C) was previously used as a laxative but has been banned due to safety concerns.

Correct Answer: A

Rationale: Step 1: Digitalis increases vagal tone by enhancing parasympathetic activity. Step 2: This results in a decrease in heart rate and improved contractility. Step 3: Therefore, choice A is correct as it accurately states that digitalis increases vagal tone. Summary: Choices B, C, and D are incorrect because digitalis does increase vagal tone, which is a specific action of the medication.

Correct Answer: D

Rationale: The correct answer is D, "All of the above," because all three choices are nitrates used for the prevention of angina attacks. Nitroglycerin, in both ointment and oral sustained-release forms, works by dilating blood vessels to improve blood flow to the heart, reducing angina symptoms. Isosorbide mononitrate is another nitrate used for the same purpose. Therefore, all three options are effective in preventing angina attacks. Options A, B, and C are incorrect because each drug listed is individually used for angina prevention, making the correct answer D, as it includes all the effective drugs for this purpose.