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: Blurred vision is not a common or serious side effect of simvastatin, as it does not affect the eyes or the vision. Blurred vision may be caused by other factors, such as diabetes, hypertension, or eye disorders.

Choice B reason: Orthostatic hypotension is not a common or serious side effect of simvastatin, as it does not affect the blood pressure or the vascular tone. Orthostatic hypotension may be caused by other factors, such as dehydration, anemia, or medication interactions.

Choice C reason: Urinary retention is not a common or serious side effect of simvastatin, as it does not affect the urinary tract or the bladder function. Urinary retention may be caused by other factors, such as prostate enlargement, infection, or nerve damage.

Choice D reason: Muscle weakness is a common and serious side effect of simvastatin, as it can indicate muscle damage or rhabdomyolysis. Rhabdomyolysis is a life-threatening condition that causes the breakdown of muscle tissue and the release of myoglobin into the bloodstream, which can lead to kidney failure. Muscle weakness may be accompanied by muscle pain, tenderness, or dark urine. The nurse should monitor the client's creatine kinase (CK) levels and report any signs of muscle damage to the provider.