A nurse is providing teaching for a client who has a new prescription for an antibiotic. Which of the following statements should the nurse make?

Choice A reason: This is correct. Nausea, vomiting, and diarrhea are the most common side effects of metformin, especially when the drug is started or the dose is increased. These side effects occur because metformin can interfere with the absorption of glucose and other nutrients in the intestines, causing osmotic diarrhea. The nurse should advise the client to take metformin with food, start with a low dose and gradually increase it, and drink plenty of fluids to prevent dehydration. The nurse should also monitor the client for signs of lactic acidosis, a rare but serious complication of metformin that causes severe diarrhea, abdominal pain, muscle cramps, and difficulty breathing.

Choice B reason: This is incorrect. Palpitations are not a common side effect of metformin. Palpitations are the sensation of a rapid, irregular, or pounding heartbeat, which can be caused by various factors, such as stress, anxiety, caffeine, nicotine, or heart problems. Metformin does not affect the heart rate or rhythm directly, but it can lower the blood sugar levels, which can trigger the release of adrenaline, a hormone that can cause palpitations. The nurse should check the client's blood sugar levels and advise the client to eat regular meals and snacks, avoid alcohol and caffeine, and report any chest pain or shortness of breath.

Choice C reason: This is incorrect. Headaches are not a common side effect of metformin. Headaches are the pain or discomfort in the head, scalp, or neck, which can be caused by various factors, such as stress, dehydration, or sinus infection. Metformin does not cause headaches directly, but it can lower the blood sugar levels, which can cause headaches as a symptom of hypoglycemia. The nurse should check the client's blood sugar levels and advise the client to eat regular meals and snacks, drink plenty of water, and take painkillers as needed.

Choice D reason: This is incorrect. Heartburn is not a common side effect of metformin. Heartburn is the burning sensation in the chest or throat, which is caused by the reflux of stomach acid into the esophagus. Metformin does not cause heartburn directly, but it can worsen it if the client already has gastroesophageal reflux disease (GERD), a condition where the lower esophageal sphincter is weak or relaxed and allows the acid to flow back. The nurse should advise the client to take metformin with food, avoid spicy or fatty foods, elevate the head of the bed, and take antacids as needed.

Choice A reason: Bradycardia is not an adverse effect of diphenhydramine. Diphenhydramine is a medication that blocks the action of histamine, a chemical that causes allergic reactions and inflammation. Diphenhydramine can also block the action of acetylcholine, a neurotransmitter that stimulates the parasympathetic nervous system. Diphenhydramine does not affect the heart rate or blood pressure significantly, and it is not associated with bradycardia, which is a slow heart rate that can cause dizziness, fatigue, or fainting. The nurse should monitor the vital signs of the client after administering diphenhydramine, but bradycardia is not a common or expected outcome.

Choice B reason: Sedation is an adverse effect of diphenhydramine. Diphenhydramine is a medication that blocks the action of histamine, a chemical that causes allergic reactions and inflammation. Diphenhydramine can also block the action of acetylcholine, a neurotransmitter that stimulates the parasympathetic nervous system. Diphenhydramine can cross the bloodbrain barrier and block the histamine receptors in the brain, which are involved in regulating the sleepwake cycle and alertness. Diphenhydramine can cause sedation, sleepiness, drowsiness, dizziness, and impaired coordination, which can affect the performance and safety of the client. The nurse should instruct the client to avoid driving, operating machinery, or performing other tasks that require mental alertness after taking diphenhydramine, and to take the medication at bedtime or as needed for sleep.

Choice C reason: Constipation is not an adverse effect of diphenhydramine. Diphenhydramine is a medication that blocks the action of histamine, a chemical that causes allergic reactions and inflammation. Diphenhydramine can also block the action of acetylcholine, a neurotransmitter that stimulates the parasympathetic nervous system. Diphenhydramine does not affect the gastrointestinal motility or secretion significantly, and it is not associated with constipation, which is a condition of infrequent or difficult bowel movements. The nurse should encourage the client to eat a balanced and highfiber diet, drink plenty of fluids, and exercise regularly to prevent or treat constipation, but diphenhydramine is not a contributing factor.

Choice D reason: Hypertension is not an adverse effect of diphenhydramine. Diphenhydramine is a medication that blocks the action of histamine, a chemical that causes allergic reactions and inflammation. Diphenhydramine can also block the action of acetylcholine, a neurotransmitter that stimulates the parasympathetic nervous system. Diphenhydramine does not affect the blood pressure or the vascular tone significantly, and it is not associated with hypertension, which is a condition of high blood pressure that can cause headaches, chest pain, or stroke. The nurse should monitor the blood pressure of the client after administering diphenhydramine, but hypertension is not a common or expected outcome.