Final answer:
The nurse should hold the dose of propranolol and contact the healthcare provider if the patient exhibits symptoms such as an increased heart rate, which could indicate potential contraindications like an overactive thyroid or other conditions where beta-blockers might be harmful.
Step-by-step explanation:
When preparing to administer propranolol, a nurse should be vigilant for signs that could indicate the drug is contraindicated or could cause harm to the patient. Propranolol is a non-selective beta-blocker, which means that it reduces the workload on the heart and blocks the release of adrenaline, lowering blood pressure and heart rate. Given the symptoms provided for Patient B, which include weight loss, profuse sweating, increased heart rate, and difficulty sleeping, these could potentially be indicative of an overactive thyroid or hyperthyroidism.
If the patient is experiencing an increased heart rate (tachycardia), this could be a concern because propranolol slows the heart rate and could potentially lead to bradycardia. It's also important to consider that symptoms like profuse sweating and weight loss might suggest an overactive thyroid, and propranolol could mask the symptoms of thyroid storm, which is a life-threatening condition. In such cases, the nurse would hold the dose and immediately contact the healthcare provider for further evaluation and instructions.