A nurse in a coronary care unit is admitting a client who has had CPR following a cardiac arrest. The client is receiving lidocaine IV at 2 mg/min. When the client asks the nurse why he is receiving that medication, the nurse should explain that it has which of the following actions?

Choice A reason: Bradycardia is not an adverse effect of diphenhydramine. Bradycardia is a slow heart rate, usually below 60 beats per minute. Diphenhydramine is an antihistamine that blocks the effects of histamine, a chemical that causes allergic reactions. Diphenhydramine does not affect the heart rate, although it may cause palpitations or irregular heartbeat in some cases.

Choice B reason: Constipation is an adverse effect of diphenhydramine. Constipation is a condition in which the bowel movements are infrequent, hard, or difficult to pass. Diphenhydramine has anticholinergic properties, which means it inhibits the activity of acetylcholine, a neurotransmitter that regulates the smooth muscle contraction in the gastrointestinal tract. Diphenhydramine can reduce the intestinal motility and cause constipation, as well as dry mouth, blurred vision, and urinary retention.

Choice C reason: Hypertension is not an adverse effect of diphenhydramine. Hypertension is a condition in which the blood pressure is abnormally high, usually above 140/90 mmHg. Diphenhydramine does not affect the blood pressure, although it may cause orthostatic hypotension, which is a sudden drop in blood pressure when changing positions from lying to standing. This can cause dizziness, fainting, or falls.

Choice D reason: Sedation is an adverse effect of diphenhydramine. Sedation is a state of reduced alertness, awareness, or responsiveness. Diphenhydramine can cross the blood-brain barrier and affect the central nervous system, causing drowsiness, fatigue, impaired coordination, and reduced mental performance. Diphenhydramine can also potentiate the effects of alcohol and other sedatives, such as benzodiazepines, opioids, or barbiturates. The nurse should advise the client to avoid driving, operating machinery, or performing other tasks that require attention and concentration while taking diphenhydramine.

Choice A reason: The client has a history of hypertension is not the correct answer. Hypertension is a condition in which the blood pressure is abnormally high, usually above 140/90 mmHg. Propranolol is a beta-blocker that lowers the blood pressure and reduces the workload of the heart. Propranolol is indicated for the treatment of hypertension and angina pectoris, which is a type of chest pain caused by reduced blood flow to the heart. The nurse does not need to report this finding to the provider, as it is consistent with the prescription.

Choice B reason: The client has a history of hypothyroidism is not the correct answer. Hypothyroidism is a condition in which the thyroid gland does not produce enough thyroid hormones, which regulate the metabolism and energy levels. Propranolol can mask some of the signs of hypothyroidism, such as tachycardia, tremors, and anxiety. Propranolol can also interfere with the absorption and conversion of thyroid hormones. The nurse should monitor the client's thyroid function tests and report any abnormal values to the provider, but this finding is not a contraindication to the use of propranolol.

Choice C reason: The client has a history of bronchial asthma is the correct answer. Bronchial asthma is a chronic inflammatory disorder of the airways that causes wheezing, coughing, and shortness of breath. Propranolol is a non-selective beta-blocker that blocks the beta-1 receptors in the heart and the beta-2 receptors in the lungs. Blocking the beta-2 receptors can cause bronchoconstriction, which can worsen the symptoms of asthma and trigger an asthma attack. Propranolol is contraindicated in clients who have bronchial asthma, and the nurse should report this finding to the provider immediately.

Choice D reason: The client has a history of migraine headaches is not the correct answer. Migraine headaches are recurrent episodes of severe and throbbing pain, usually on one side of the head, that can be accompanied by nausea, vomiting, and sensitivity to light and sound. Propranolol is effective in preventing migraine headaches, as it reduces the frequency and severity of the attacks. Propranolol is indicated for the prophylaxis of migraine headaches, and the nurse does not need to report this finding to the provider, as it is consistent with the prescription.