A nurse is teaching a client who has a new prescription for hydrochlorothiazide for management of hypertension. Which of the following instructions should the nurse include?

Choice A reason: Reducing intake of potassium-rich foods is not necessary for clients taking hydrochlorothiazide, as this medication can cause hypokalemia (low potassium levels) due to increased potassium excretion in the urine. Clients may need to increase their intake of potassium-rich foods or take potassium supplements to prevent hypokalemia.

Choice B reason: Avoiding grapefruit juice is not necessary for clients taking hydrochlorothiazide, as this medication does not interact with grapefruit juice. Grapefruit juice can affect the metabolism of some other medications, such as statins, calcium channel blockers, and cyclosporine, by inhibiting the enzyme CYP3A4 in the liver.

Choice C reason: Taking this medication before bedtime is not advisable for clients taking hydrochlorothiazide, as this medication can cause increased urination and nocturia (nighttime urination). Clients should take this medication in the morning or at least 6 hours before bedtime to avoid disrupting their sleep.

Choice D reason: Monitoring for leg cramps is an important instruction for clients taking hydrochlorothiazide, as this medication can cause muscle cramps due to electrolyte imbalances, such as hypokalemia, hyponatremia (low sodium levels), or hypomagnesemia (low magnesium levels). Clients should report any signs of muscle cramps, weakness, or fatigue to their provider.

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.