Cocaine may cause:

Correct Answer: D

Rationale: Cocaine may cause powerful vasoconstrictive reactions, leading to myocardial infarctions due to increased blood pressure and heart strain. It can also result in multiple brain perfusion defects due to restricted blood flow. Additionally, cocaine use during pregnancy can lead to spontaneous abortion due to its harmful effects on fetal development. Therefore, the correct answer is D, as all of these adverse effects are associated with cocaine use. Choices A, B, and C are incorrect as they do not cover the full spectrum of potential harm caused by cocaine.

Correct Answer: A

Rationale: The correct answer is A: TRUE. Iron deficiency anemia leads to symptoms like pallor, fatigue, dizziness, exertional dyspnea due to decreased oxygen-carrying capacity in the blood. Iron is essential for hemoglobin production, which carries oxygen to tissues. Other choices are incorrect: B is false because iron deficiency anemia does lead to these symptoms. C is incorrect because not all symptoms listed are present in every case of iron deficiency anemia. D is incorrect because the symptoms mentioned are associated with iron deficiency anemia.

Correct Answer: C

Rationale: Rationale: 1. Dobutamine is a beta-1 adrenergic receptor agonist used as an inotropic drug. 2. Continuous use of dobutamine leads to receptor desensitization, causing tolerance. 3. Tolerance develops within a few days due to downregulation of beta-1 receptors. 4. Amrinone and amiodarone are not inotropic drugs and do not cause tolerance. 5. Adenosine is not an inotropic drug and has a rapid onset and short duration of action.

Correct Answer: D

Rationale: The correct answer is D: Propranolol. Propranolol is a non-selective beta-blocker, affecting both beta1 and beta2 receptors. In contrast, choices A, B, and C are cardioselective beta1-adrenoceptor-blocking drugs. Metoprolol, Talinolol, and Atenolol specifically target beta1 receptors in the heart, making them suitable for angina treatment. Propranolol, being non-selective, may lead to unwanted side effects related to beta2 receptor blockade, such as bronchoconstriction and peripheral vasoconstriction. Therefore, for angina patients, cardioselective beta1 blockers are preferred to minimize potential adverse effects.

Correct Answer: B

Rationale: The correct answer is B: Vasoconstrictors. Vasoconstrictors are used to increase blood pressure in chronic hypotension by constricting blood vessels, thus raising blood pressure. Positive inotropic drugs (A) increase the strength of the heart's contractions, which is not the primary concern in hypotension. Plasmoexpanders (C) are used to increase blood volume, not necessarily blood pressure. Analeptics and tonics (D) are more commonly used for conditions like fatigue or depression, not specifically for chronic hypotension.