The nurse is caring for a client who is refusing to take their prescribed metformin (Glucophage). The nurse understands that the most common side effects of metformin are:

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..

Choice A reason: Peak level is the correct term to describe the highest concentration of a drug in the blood after it is administered. Peak level is also known as peak plasma concentration or Cmax, and it reflects the rate and extent of drug absorption. Peak level is influenced by factors such as the route of administration, the dose, the formulation, and the bioavailability of the drug. Peak level is important to monitor for drugs that have a narrow therapeutic range, meaning that there is a small difference between the effective and toxic doses. The nurse should measure the peak level at the appropriate time after the drug administration, and adjust the dose or the frequency as needed to achieve the desired therapeutic effect and avoid adverse effects .

Choice B reason: Halflife is not the correct term to describe the highest concentration of a drug in the blood after it is administered. Halflife is the time it takes for the concentration of a drug in the blood to decrease by 50%. Halflife reflects the rate of drug elimination, which depends on factors such as the metabolism and excretion of the drug. Halflife is important to determine the dosing interval and the time to reach steady state. The nurse should consider the halflife of the drug when prescribing or administering the drug, and avoid drug accumulation or subtherapeutic levels .

Choice C reason: Trough level is not the correct term to describe the highest concentration of a drug in the blood after it is administered. Trough level is the lowest concentration of a drug in the blood before the next dose is given. Trough level reflects the balance between drug absorption and elimination, and it indicates the minimum effective concentration of the drug. Trough level is important to monitor for drugs that have a narrow therapeutic range, meaning that there is a small difference between the effective and toxic doses. The nurse should measure the trough level just before the next dose of the drug, and adjust the dose or the frequency as needed to achieve the desired therapeutic effect and avoid adverse effects .

Choice D reason: Steady state is not the correct term to describe the highest concentration of a drug in the blood after it is administered. Steady state is the condition when the rate of drug administration is equal to the rate of drug elimination, and the concentration of the drug in the blood remains constant. Steady state is usually reached after four to five halflives of the drug, and it reflects the optimal therapeutic level of the drug. Steady state is important to maintain for drugs that have a long halflife or a narrow therapeutic range, meaning that there is a small difference between the effective and toxic doses. The nurse should ensure that the drug is administered at regular intervals and at the appropriate dose to achieve and maintain steady state.