A nurse is teaching a client who has a new prescription for transdermal nitroglycerin to treat angina pectoris. Which of the following instructions should the nurse include in the teaching?

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: Infection is the correct condition that the client is at increased risk for. Agranulocytosis is a severe decrease in the number of granulocytes, which are a type of white blood cell that fight infection. Propylthiouracil is an antithyroid drug that can cause agranulocytosis as a rare but serious side effect. The client with agranulocytosis is more susceptible to bacterial and fungal infections, and may present with fever, sore throat, mouth ulcers, and skin lesions.

Choice B reason: Excessive bleeding is not the correct condition that the client is at increased risk for. Agranulocytosis does not affect the platelets, which are the blood cells that help with clotting. Propylthiouracil does not cause bleeding disorders, although it may interact with anticoagulants and increase their effect.

Choice C reason: Hyperglycemia is not the correct condition that the client is at increased risk for. Agranulocytosis does not affect the insulin, which is the hormone that regulates blood glucose levels. Propylthiouracil does not cause hyperglycemia, although it may interfere with the metabolism of oral hypoglycemic agents and decrease their effect.

Choice D reason: Ecchymosis is not the correct condition that the client is at increased risk for. Ecchymosis is a bruise caused by bleeding under the skin. Agranulocytosis does not cause ecchymosis, as it does not affect the blood vessels or the platelets. Propylthiouracil does not cause ecchymosis, although it may increase the risk of skin rash and pruritus.