NCLEX-PN › Drug Interactions
You are the nurse taking care of a patient being treated with metronidazole for a lower gastrointestinal infection. Which of the following instructions should you give the patient?
"Do not consume alcohol while taking this medication."
"Avoid operating heavy machinery while taking this medication."
"Do not eat spinach when taking this medication."
"Lie flat for 30 minutes after taking this medication."
"Do not take your cholesterol medication when taking this medication."
The correct answer is "Do not consume alcohol while taking this medication."
In this question, what is really being tested is your knowledge of side effects/interactions with metronidazole. One of the major interactions to be aware of with metronidazole is that it can cause an unpleasant interaction when consumed with alcohol that is very similar to the symptoms that occur when one consumes alcohol while taking the alcohol deterrent, Antabuse. This reaction includes severe abdominal pain/cramping, nausea, vomiting, facial flushing, and headaches. Patients should avoid drinking alcohol while taking metronidazole and for three days after completing their course.
Eating spinach, lying flat for 30 minutes after taking metronidazole, taking cholesterol medication while taking metronidazole, and operating heavy machinery while taking metronidazole are inappropriate recommendations, as there are no known direct associations between metronidazole and spinach consumption, head elevation, cholesterol medications, or level of consciousness.
The nurse cares for a patient with a urinary tract infection (UTI). The patient has an allergy to penicillins. Which of the following medications is contraindicated for this patient’s illness?
Ceftriaxone
Streptomycin
Ciprofloxacin
Clindamycin
Sulfasalazine
Patients with allergies to penicillins often have cross-allergies to cephalosporins. Cephalosporins such as ceftriaxone should be avoided by patients with these allergies. Patients with cephalosporin allergies should also avoid pencillins. Streptomycin, ciprofloxacin, clindamycin, and sulfasalazine may all treat UTIs but are not penicillins.
The nurse assesses patient medications at a primary care clinic. Which of the following patients with osteoporosis should not be prescribed alendronate?
A 70-year-old female with chronic kidney disease.
A 65-year-old female who is allergic to iodine.
A 62-year-old female on a low-calorie diet.
A 58-year-old female taking estrogen.
A 53-year-old female taking captopril.
The nurse should identify alendronate as a medication that slows bone loss, and is commonly prescribed to patients with osteoporosis to maintain bone density. The nurse should assess ages and risk factors associated with both osteoporosis and alendronate use. Alendronate is contraindicated in patients who are allergic to it, have esophageal issues such as narrowing or blockages, are unable to sit or stand upright for 30 minutes (after taking), or have kidney dysfunction or low blood calcium levels. Therefore, the nurse should question the order of alendronate for the 70-year-old female with chronic kidney disease. The nurse should also recognize that older patients are more likely to experience problems such as contraindications with medications due to polypharmacy, so the age of the 70-year-old female should concern the nurse. Alendronate is not contraindicated in patients who are on low-calorie diets, and it is not contraindicated with estrogen or captopril.
A 65-year-old male client is being discharged from the hospital on warfarin therapy for chronic atrial fibrillation. The nurse is aware that the discharge teaching needs to include which of the following instructions?
Alcohol should be limited to no more 1-2 servings on an occasional basis
When having dental procedures there is no need to discontinue warfarin
Increase intake of leafy green vegetables
Warfarin is a medication that does not require monitoring
Use a blade when shaving; avoid electric razors
Warfarin is an anticoagulant, alcohol can increase this effect, so it should be limited or avoided. Leafy greens, contain vitamin K and can reverse the action of warfarin. Warfarin needs monthly monitoring to check client internal normalized ratio (INR). Dental and surgical procedures may require discontinuation temporarily to avoid excess bleeding. Electric razors are preferred.
A nurse checks the lithium level of a 28-year-old patient that has been prescribed lithium citrate and sees the level is 1.5 mEq/L, and verifies that the patient has not taken more than the prescribed medication. The nurse advises the client to:
Eat salty foods
Exercise more often
Drink 4 glasses of water a day
Eat more red meat
Low sodium diets when taking lithium mood-stabilizing drugs can result in toxicity. The nurse should tell the patient to eat salty foods to increase sodium intake.
The nurse reviews medication orders for a patient with acute gastritis. Which of the following medications is contraindicated for this patient?
Ibuprofen
Calcium supplements
Furosemide
Acetaminophen
Propranolol
Patients with acute gastritis experience inflammation in the gastric mucosa. They must discontinue use of drugs that may cause gastritis or inflammation, such as NSAIDs like ibuprofen or alcohol consumptions. Calcium gluconate, furosemide, acetaminophen, and propranolol are not associated with acute gastritis and can be taken safely by this patient.
You are the nurse taking care of a patient who is being discharged on warfarin for a pulmonary embolism. Which of the following statements would you most likely give when counseling the patient about warfarin use?
"Do not consume grapefruit juice when taking warfarin."
"You can participate in all physical activities, including contact sports, while taking warfarin."
"Your risk of bleeding events is not significantly elevated while taking warfarin."
"You have an increased risk of seizures while taking warfarin."
"You can discontinue taking aspirin, if you were already taking aspirin, while you are taking warfarin."
The correct answer is "Do not consume grapefruit juice while taking warfarin."
This advice is correct because warfarin is metabolized and inactivated by the cytochrome P-450 (CYP450) enzyme complex, and grapefruit juice is an inhibitor of CYP450. Therefore, when grapefruit juice is consumed, the efficacy of inactivation of drugs, like warfarin, is impaired, which increases the effective level of warfarin circulating in the patient's blood. Consequently, even if the patient is taking the prescribed dose of warfarin, the effect of the drug may be greater than intended if taken with grapefruit juice, which can predispose to dangerous, potentially fatal bleeding effects. Thus, avoiding grapefruit juice while taking warfarin is the most appropriate advice for this patient.
The patient's risk of bleeding events is elevated while taking warfarin, even without consuming grapefruit juice, though the benefit of preventing future blood clots and pulmonary emboli outweighs the risk of bleeding. Due to the risk of bleeding events while taking warfarin, it would be inappropriate to advise the patient to continue participating in contact sports.
Warfarin is not known to cause an increased risk of seizures.
It would be inappropriate to advise a patient to discontinue taking aspirin while on warfarin unless explicitly instructed for a medical reason by his physician. While aspirin is an anti-platelet agent, which can predispose to bleeding, and warfarin is an anti-coagulant, which also independently can predispose to bleeding, each medication has a clinical indication in the patient, and therefore it is inappropriate to simply discontinue one medication.
You are counseling a new patient about initiating a combined oral contraceptive pill (OCP). You know that certain medications can affect the metabolism of OCP's. Which of the following medications could alter the metabolism of OCP's?
Ciprofloxacin
Lisinopril
Aspirin
Fluoxetine
Docusate
The correct answer is "Ciprofloxacin."
This choice is correct because the combined oral contraceptive pill (OCP) is metabolized and inactivated by the cytochrome P-450 (CYP450) enzyme complex, and ciprofloxacin, a fluoroquinolone antibiotic, is an inhibitor of CYP450. Therefore, when ciprofloxacin is taken, the efficacy of inactivation of drugs, like OCP's, is impaired, which increases the effective level of OCP's circulating in the patient's blood. Consequently, even if the patient is taking the prescribed dose of OCP's, the effect of the drug may be greater than intended if taken with ciprofloxacin or other drugs that inhibit CYP450, which can make the potential adverse effects of OCP's more likely to occur, or occur with greater severity than if that patient had not taken ciprofloxacin with it.
Neither lisinopril (an ACE inhibitor), fluoxetine (an SSRI), Docusate (a stool softener), nor aspirin (an anti-inflammatory, anti-platelet agent) appreciably induce or inhibit CYP450 and therefore none of them has an appreciable effect on OCP metabolism.
Patients taking which of the following antibiotics should be cautioned against any alcohol consumption?
Metronidazole
Mupirocin
Neomycin
Penicillin
Drinking alcohol while taking metronidazole can result in nausea, vomiting, flushing, and tachycardia. This is due to metronidazole's inhibition of acetaldehyde dehydrogenase, the enzyme responsible for acetaldehyde catabolism. Reduced function of acetaldehyde dehydrogenase results in toxic levels of acetaldehyde in the blood.
The pediatric oncology nurse talks to relatives of a child with leukemia. The patient’s uncle wants to donate blood for transfusion. Which of the following donor conditions would preclude him from donating blood?
A history of hepatitis C 4 years ago
A diagnosis of diverticulosis 10 years ago
A history of Crohn’s disease in remission 3 years
A previous cholecystectomy 2 years ago
A dose of ibuprofen 20 hours ago
Blood donors must be healthy and feeling well to donate blood; they must also be free of blood-borne pathogens such as HIV/AIDS and hepatitis B, C, and D. Diverticulosis, Crohn’s disease, a previous cholecystectomy, and a dose of ibuprofen the previous day do not preclude this person from donating blood.