A nurse is reviewing medication for a patient with a recent myocardial infarction. The physician has prescribed aspirin. What is the primary purpose of this medication in this context?

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.

Choice A reason: This is incorrect. A recent history of diarrhea for 3 days is not a contraindication for receiving a cephalosporin antibiotic. However, the nurse should monitor the client for signs of dehydration and electrolyte imbalance, and advise the client to drink plenty of fluids and avoid caffeine and alcohol. The nurse should also be aware that cephalosporins can cause or worsen diarrhea in some people, especially if they disrupt the normal flora of the gut. In rare cases, cephalosporins can cause a serious infection called Clostridioides difficile (C. difficile) colitis, which is characterized by severe diarrhea, abdominal pain, fever, and blood or pus in the stool. The nurse should instruct the client to report any of these symptoms and to avoid taking antidiarrheal drugs without consulting the doctor.

Choice B reason: This is incorrect. Serum creatinine 0.8 mg/dL is not a contraindication for receiving a cephalosporin antibiotic. Serum creatinine is a measure of kidney function, and a normal range for adults is 0.6 to 1.2 mg/dL. A high serum creatinine level may indicate kidney damage or impairment, which can affect the clearance of cephalosporins and increase the risk of toxicity. Therefore, the dose of cephalosporins may need to be adjusted in people with kidney problems, except for ceftriaxone and cefoperazone, which are excreted mainly through the bile. The nurse should check the client's renal function tests and the doctor's orders before administering a cephalosporin antibiotic.

Choice C reason: This is incorrect. A history of phlebitis following an IV infusion of 0.9% sodium chloride with 10 mEq of potassium chloride is not a contraindication for receiving a cephalosporin antibiotic. Phlebitis is the inflammation of a vein, which can be caused by mechanical, chemical, or infectious factors. Some IV solutions, such as potassium chloride, can irritate the vein and cause phlebitis. However, this does not mean that the client is allergic or intolerant to cephalosporins, which are usually well tolerated by the veins. The nurse should assess the client's IV site for signs of phlebitis, such as redness, swelling, pain, or warmth, and change the site if needed. The nurse should also dilute the cephalosporin antibiotic according to the manufacturer's instructions and administer it slowly over the recommended time to minimize the risk of phlebitis.

Choice D reason: This is correct. A severe allergy to penicillins is a contraindication for receiving a cephalosporin antibiotic. Penicillins and cephalosporins belong to the same class of beta lactam antibiotics, which share a similar chemical structure. Therefore, people who are allergic to penicillins have a higher chance of being allergic to cephalosporins, especially the first and secondgeneration ones. An allergic reaction to cephalosporins can range from mild skin rashes to life-threatening anaphylaxis, which is a severe hypersensitivity reaction that causes difficulty breathing, low blood pressure, and shock. The nurse should ask the client about their allergy history and the type and severity of their reactions. The nurse should report any history of penicillin allergy to the doctor and avoid giving cephalosporins to the client unless the doctor confirms that it is safe to do so..