Adrenaline combination with local anesthetics has the following effects EXCEPT:

Correct Answer: D

Rationale: Correct Answer: D. Increases blood flow to the injection area. Rationale: 1. Adrenaline is a vasoconstrictor that reduces blood flow in the injection area. 2. By constricting blood vessels, adrenaline limits the absorption of the local anesthetic, leading to prolonged local action. 3. Adrenaline also helps in reducing the systemic toxicity of the local anesthetic by limiting its absorption. 4. Therefore, the correct answer is D as adrenaline does not increase blood flow to the injection area.

Correct Answer: D

Rationale: The correct answer is D: Tachycardia. Anticholinergic medications block the action of acetylcholine, leading to increased heart rate (tachycardia) by inhibiting the parasympathetic nervous system. Excessive salivation (choice A) is a cholinergic effect, not anticholinergic. Bradycardia (choice B) is not consistent with anticholinergic side effects. Diarrhea and colic (choice C) are more commonly associated with cholinergic, not anticholinergic, effects.

Correct Answer: B

Rationale: Correct Answer: B Rationale: 1. Prazosin and phentolamine both antagonize alpha1-receptors, leading to vasodilation and decreased blood pressure. 2. Both drugs are competitive antagonists, competing with norepinephrine at alpha1-receptors. 3. However, phentolamine causes reflex tachycardia due to its non-selective alpha-adrenergic blockade, unlike prazosin. 4. Therefore, the statement that both cause the same degree of tachycardia is incorrect based on their pharmacological differences.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Isoprenaline is a beta-adrenergic agonist. 2. It directly stimulates beta adrenoceptors, leading to effects like increased heart rate. 3. Isoprenaline causes bronchodilation by relaxing bronchial smooth muscles. 4. It also causes vasodilation, leading to decreased blood pressure. 5. Isoprenaline does not have a direct effect on intestinal motility, making option D incorrect. Summary: Option D is incorrect as isoprenaline does not increase intestinal motility. Options A, B, and C are correct as isoprenaline directly stimulates beta adrenoceptors, relaxes bronchial smooth muscles, and decreases blood pressure, respectively.

Correct Answer: C

Rationale: The correct answer is C - Phentolamine plus propranolol. Phentolamine is an alpha-adrenergic blocker that can counteract the effects of high noradrenaline levels, while propranolol is a non-selective beta blocker that can further control the symptoms by blocking beta-adrenergic receptors. Combining both drugs can effectively block all adrenergic receptors and normalize the signs and symptoms of pheochromocytoma. A: Propranolol alone cannot block all adrenergic receptors, as it only targets beta receptors. B: Phentolamine alone can block alpha receptors but does not address the beta receptors. D: Atropine plus phenylephrine combination does not cover all adrenergic receptors involved in pheochromocytoma.