Drug Interactions and Biotransformation - NCLEX-PN

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 ringing in the ear is tinnitus, which is indicative of ototoxicity. Nausea, metallic taste in mouth, difficulty swallowing and skin reactions are not associated with the development of ototoxicity.

Nausea, vomiting, and diarrhea are common symptoms of digoxin toxicity. Other symptoms may include confusion, anorexia, irregular heartbeat, and palpitations. Tremors, mood swings, and rash are not generally seen with digoxin toxicity.

All of these are potential side effects of ACE (angiotensin-converting enzyme) inhibitors such as enalapril, but angioedema (the swelling of the face, lips, and/or tongue) is a potentially life threatening condition, as swelling can obstruct the airway.

Meperidine is contraindicated because in high doses it can form a toxic metabolite that can lead to seizures. All other drugs listed are appropriate for pain control for sickle cell crisis.

Alendronate is a bisphosphonate drug used in the treatment of osteoporosis and osteogenesis imperfecta. An individual taking this medication should be instructed to remain upright for a minimum of thirty minutes after ingestion in order to avoid esophagitis. Other gastrointestinal adverse effects of alendronate include esophageal strictures, achalasia, gastric ulcers, and gastritis. None of the other medications listed are associated with esophagitis.

The most common side effects of beta blockers are fatigue, dizziness, weakness, cold hands or feet, dry mouth, headache, nausea, diarrhea, and shortness of breath.

Chlorpropamide, an antidiabetic medication in the sulfonylurea class, has been associated with drug-induced SIADH (syndrome of inappropriate antidiuretic hormone secretion). This is a rare but serious complication that will generally resolve once drug treatment has stopped. None of the other drugs listed are associated with this side effect.

Most opiates can cause respiratory depression when taken in toxic levels. They do this by reducing the sensitivity of respiratory center neurons to carbon dioxide, which results in decreased breathing. In more moderate cases brain damage can precede death due to CNS hypoxia. Opiates generally are not associated with liver failure (unless taken as a combination drug with acetaminophen, such as hydrocodone), heart attack, or serotonin syndrome.

The correct answer is "diarrhea." Diarrhea is a common side effect associated with antibiotic use, including cephalexin. This diarrhea is typically self-limited and resolves within the first day or two of administration. Sometimes patients are advised to take a probiotic or consume yogurt when starting a new antibiotic if they experienced diarrhea when starting antibiotics in the past.

Neither headaches, hair loss, pharyngitis, nor necrotizing skin rash are known common side effects of cephalexin use.

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 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.

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.

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.

Tyramine is normally broken down by monoamine oxidase. Monoamine oxidase inhibitors prevent the breakdown and removal, leading abnormally high tyrosine levels in the body. This can in turn displace the storage and increase release of multiple other catecholamines, including dopamine, epinephrine, and norepinephrine. This increase in free catecholamines can cause a hypertensive crisis.

Tyramine is an amino-acid that is present in many foods, including fermented, aged, or smoked foods, aged cheese, fish, pork, cold cuts, chocolate, alcohol, yeasty breads, peanuts, and beans. High tyramine intake in patients on MAOI's can cause hypertensive crisis due to monoamine oxidase's role in tyramine breakdown.

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 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 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.