A patient who has been taking opioids for several weeks tells the nurse, "The medication doesn't seem to work as well anymore." The nurse recognizes this as a sign of:

Choice A reason: This is correct. Dry mouth is a common side effect of anticholinergic drugs. It occurs because anticholinergic drugs block the action of acetylcholine, a neurotransmitter that stimulates the secretion of saliva and other fluids in the body. Dry mouth can cause discomfort, bad breath, and increased risk of dental problems¹.

Choice B reason: This is incorrect. Constricted bronchioles are not a side effect of anticholinergic drugs. In fact, anticholinergic drugs can cause the opposite effect: dilated bronchioles. This is because anticholinergic drugs block the action of acetylcholine, a neurotransmitter that causes the smooth muscles of the airways to contract. Dilated bronchioles can improve breathing and reduce wheezing in people with respiratory disorders, such as asthma or COPD.

Choice C reason: This is incorrect. Increased heart rate is not a side effect of anticholinergic drugs. In fact, anticholinergic drugs can cause the opposite effect: decreased heart rate. This is because anticholinergic drugs block the action of acetylcholine, a neurotransmitter that slows down the heart rate and lowers the blood pressure. Decreased heart rate can be beneficial for people with certain heart conditions, such as atrial fibrillation or tachycardia.

Choice D reason: This is correct. Dilated pupils are a common side effect of anticholinergic drugs. It occurs because anticholinergic drugs block the action of acetylcholine, a neurotransmitter that controls the muscles of the iris, which regulate the size of the pupils. Dilated pupils can cause blurred vision, sensitivity to light, and difficulty focusing.

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..