The nurse is preparing to administer dipyridamole (Persantine). Which statement about this drug is true?

Correct Answer: D

Rationale: The correct answer is D. Dipyridamole is used in combination with warfarin to prevent postoperative thromboembolic complications. This is because dipyridamole enhances the effects of warfarin, resulting in improved prevention of blood clots. Choice A is incorrect because dipyridamole does not have antiinflammatory or antipyretic properties. Choice B is incorrect because dipyridamole does not have analgesic properties and its main effect is antithrombotic. Choice C is incorrect because dipyridamole is not specifically indicated for reducing the risk of fatal and nonfatal thrombotic stroke.

Correct Answer: B

Rationale: Rationale: B is correct because lipophilic substances have high affinity for fats and are able to penetrate barriers easily. However, a small volume of distribution indicates that these substances are mainly confined to the plasma and do not distribute widely into interstitial and cell fluids. Summary: A is incorrect because a small volume of distribution indicates limited distribution, not widespread distribution as stated. C is incorrect as there is a correct answer. D is incorrect as not all choices are correct, only B is accurate based on the characteristics of lipophilic substances.

Correct Answer: C

Rationale: Rationale: 1. When two drugs with the same effect are taken together, and their effects sum up equally, it indicates an additive effect. 2. Additive effect means the combined effect is simply the sum of individual effects. 3. Antagonism is when the effect of one drug reduces or cancels out the effect of another. 4. Potentiation is when one drug enhances the effect of another, not equal sum. 5. None of the above is incorrect as the scenario described fits the definition of an additive effect.

Correct Answer: C

Rationale: The correct answer is C: Procaine does not readily penetrate the skin and mucosa. This is because procaine is a local anesthetic with poor lipid solubility, making it less able to penetrate through skin and mucosa efficiently. The other choices are incorrect because: A is correct as procaine contains an ester linkage; B is correct as procaine's metabolic product para-aminobenzoic acid can inhibit sulfonamide action; and D is correct as procaine is relatively short-acting compared to other local anesthetics like lidocaine. Therefore, C is the correct answer as it does not align with the properties of procaine.

Correct Answer: C

Rationale: Rationale: Scopolamine is effective for vestibular disturbances due to its central anticholinergic effects. It crosses the blood-brain barrier and blocks muscarinic receptors in the vestibular nuclei, helping to alleviate motion sickness. Atropine (A) mainly affects peripheral muscarinic receptors, not as effective. Ipratropium (B) is a bronchodilator, not used for motion sickness. Homatropine (D) is primarily used for ophthalmic purposes, not vestibular issues. Therefore, C is the correct choice.