Adverse Effects And Drug Interactions - NCLEX Rn

1. A 45-year-old client on a psychiatric unit takes lithium for bipolar disorder. The client was started on hydrochlorothiazide 3 days ago for hypertension and now reports nausea, diarrhea, and hand tremors; the nurse notes unsteady gait and slurred speech. Which medication should the nurse QUESTION for a client with these symptoms?
   Answer: Hydrochlorothiazide This question tests understanding of adverse effects and drug interactions affecting lithium levels. The client exhibits classic lithium toxicity symptoms (nausea, diarrhea, tremors, ataxia, slurred speech) after starting hydrochlorothiazide, which decreases lithium excretion and increases serum levels. Questioning hydrochlorothiazide (A) is correct because thiazide diuretics significantly increase lithium levels by reducing renal clearance, potentially causing severe neurotoxicity. Acetaminophen (B), calcium carbonate (C), and docusate sodium (D) do not interact with lithium or explain the toxicity symptoms. The nursing priority is recognizing medications that alter lithium clearance and monitoring for early toxicity signs including GI symptoms progressing to neuromuscular changes. When patients on lithium require diuretics, loop diuretics are preferred over thiazides, and lithium levels must be monitored closely with dose adjustments as needed.
2. A 57-year-old client is started on enalapril for hypertension in an outpatient clinic. Two days later the client calls reporting swelling of the lips and tongue and difficulty swallowing; no rash is noted. What finding requires IMMEDIATE intervention to prevent further complications?
   Answer: Swelling of lips and tongue after starting enalapril This question tests understanding of adverse effects and drug interactions, particularly angioedema from ACE inhibitors. The key findings are swelling of lips and tongue with difficulty swallowing shortly after starting enalapril, indicating angioedema. Immediate intervention is required to prevent airway obstruction. Dizziness, dry cough, and slightly elevated BP are common and less urgent. Assessment of airway patency is vital. The nursing process prioritizes emergency response. A transferable strategy is to monitor for angioedema in the first weeks of ACE inhibitor therapy.
3. A 58-year-old client is admitted to a medical-surgical unit for pneumonia and has a history of atrial fibrillation treated with warfarin. The provider starts trimethoprim-sulfamethoxazole today for a urinary tract infection; the client reports new gum bleeding and dark stools. Latest labs: INR 5.6 (normal 0.8–1.2). What is the nurse's PRIORITY action when noticing a drug interaction?
   Answer: Hold warfarin and notify the provider about the elevated INR and bleeding This question tests understanding of adverse effects and drug interactions between warfarin and antibiotics. The client has an INR of 5.6 (therapeutic range for atrial fibrillation is 2-3) with active bleeding symptoms after starting trimethoprim-sulfamethoxazole, which inhibits warfarin metabolism and increases anticoagulation. Holding warfarin and notifying the provider (B) is the priority action because the client has supratherapeutic anticoagulation with active bleeding that requires immediate intervention. While vitamin K and fresh frozen plasma (A) may be needed for severe bleeding, the first action is to stop the causative medication and alert the provider; giving the antibiotic with food (C) doesn't address the dangerous interaction, and increasing vitamin K foods (D) is inappropriate during acute bleeding with elevated INR. The nursing process requires assessment and immediate intervention when recognizing drug interactions that cause bleeding complications. Nurses must monitor INR closely when antibiotics are added to warfarin therapy and recognize that many antibiotics potentiate warfarin's effects through various mechanisms.
4. A 68-year-old client is hospitalized for heart failure exacerbation and receives intravenous furosemide. The client also takes gentamicin for a gram-negative infection. After 2 days, the client reports ringing in the ears and difficulty hearing conversations. Which symptom indicates an adverse effect of the medication regimen?
   Answer: Tinnitus and decreased hearing This question tests understanding of adverse effects and drug interactions, specifically ototoxicity from aminoglycosides potentiated by loop diuretics. The key symptoms are tinnitus and decreased hearing in a client on gentamicin and furosemide, indicating auditory damage. This indicates an adverse effect requiring intervention to prevent permanent hearing loss. Increased urine output is expected; mild thirst from restriction; cough from exercises are benign. Assessment of sensory changes is vital. The decision-making principle is to monitor for toxicity in combinations. A transferable strategy is to baseline and serial audiometry with ototoxic drugs.
5. A 55-year-old client with chronic kidney disease takes lisinopril and is newly prescribed trimethoprim-sulfamethoxazole for a skin infection. Two days later the client reports weakness; labs show potassium 5.9 mEq/L (normal 3.5–5.0). Which medication should the nurse QUESTION for a client with these symptoms?
   Answer: Trimethoprim-sulfamethoxazole added to lisinopril therapy This question tests understanding of adverse effects and drug interactions, focusing on hyperkalemia from ACE inhibitors and certain antibiotics. The key finding is elevated potassium with weakness in a client on lisinopril and trimethoprim-sulfamethoxazole, especially with kidney disease. Questioning trimethoprim-sulfamethoxazole added to lisinopril is appropriate as this combination risks hyperkalemia. Mupirocin, acetaminophen, and polyethylene glycol are safe. Assessment of electrolytes in renal clients is essential. The nursing process prioritizes lab monitoring. A transferable strategy is to choose alternative antibiotics in hyperkalemia risk.
6. A 47-year-old client is admitted for pancreatitis and is receiving meperidine for pain. The client also takes phenelzine for depression at home, which was continued on admission. The client becomes confused, diaphoretic, and hypertensive with BP 184/96 mmHg and HR 120/min. What finding requires IMMEDIATE intervention to prevent further complications?
   Answer: Signs of a potentially dangerous interaction between meperidine and phenelzine The client is receiving meperidine, an opioid, and phenelzine, an MAOI. The sudden confusion, diaphoresis, hypertension, and tachycardia are signs of a hazardous interaction between these drugs, often described as a hypertensive crisis or serotonin syndrome. Immediate action is needed to stop that interaction before seizures or stroke occur. The correct option is the one that names the potentially dangerous interaction between meperidine and phenelzine. The other options are pancreatitis-related or comfort findings, not the lifesaving target: decreased appetite is nonspecific and not urgent; a 7/10 pain score before the next scheduled analgesic time does not explain the deteriorating mental status and vital signs, and giving more meperidine would worsen the same interaction; mild abdominal tenderness is compatible with pancreatitis but does not account for the acute confusion and hypertension. The interaction is the only option that explains the whole clinical picture and poses the greatest immediate risk.
7. A 72-year-old client in a long-term care facility takes warfarin for atrial fibrillation and was started on trimethoprim-sulfamethoxazole yesterday for a urinary tract infection. Today the client reports new gum bleeding and has dark, tarry stools; vital signs are BP 108/64 mmHg, HR 96/min, RR 18/min, SpO2 96% on room air. What is the nurse's PRIORITY action when noticing a drug interaction?
   Answer: Hold the next dose of warfarin and notify the provider of suspected increased anticoagulation This question tests understanding of adverse effects and drug interactions, specifically the potentiation of anticoagulants by certain antibiotics. The key assessment findings are new gum bleeding and dark, tarry stools in a client on warfarin recently started on trimethoprim-sulfamethoxazole, indicating possible increased anticoagulation and gastrointestinal bleeding. Holding the next dose of warfarin and notifying the provider is the best choice to ensure client safety by preventing further bleeding and allowing for immediate medical evaluation. Administering aspirin is incorrect as it increases bleeding risk; encouraging fluids addresses the UTI but not the interaction; scheduling a routine INR ignores the urgency of symptoms. In the nursing process, assessment of bleeding signs and prompt intervention are critical for medication safety. Prioritizing notification of the provider facilitates timely adjustment of therapy. A transferable strategy is to always monitor for signs of bleeding in clients on anticoagulants when new medications are added.
8. A 45-year-old client in the emergency department has a history of anaphylaxis to penicillin documented in the chart. The client receives intravenous piperacillin-tazobactam for suspected sepsis and within minutes develops wheezing, facial swelling, and generalized hives; vital signs are BP 88/52 mmHg, HR 122/min, RR 28/min, SpO2 89% on room air. What finding requires IMMEDIATE intervention to prevent further complications?
   Answer: Stop the antibiotic infusion and administer intramuscular epinephrine per protocol This question tests understanding of adverse effects and drug interactions, specifically anaphylaxis from beta-lactam antibiotics in allergic clients. The key findings are wheezing, facial swelling, hives, and hypotension shortly after piperacillin-tazobactam in a client with penicillin allergy, indicating anaphylaxis. Stopping the infusion and administering epinephrine is immediate to reverse airway compromise and shock, prioritizing client safety. Documenting after vital signs delays care; obtaining sputum is irrelevant; diphenhydramine is adjunctive but not first-line. The nursing process requires rapid assessment and intervention in allergic reactions. Prioritizing airway and circulation is key in emergencies. A transferable strategy is to always verify allergies before administering antibiotics.
9. A 40-year-old client is admitted to the hospital with bipolar disorder and is taking lithium. The client was started on hydrochlorothiazide for hypertension 1 week ago and now has coarse tremor, vomiting, and unsteady gait; lithium level is 1.9 mEq/L (therapeutic 0.6–1.2). What is the nurse's PRIORITY action when noticing a drug interaction?
   Answer: Hold lithium and notify the provider of suspected thiazide-related lithium toxicity This question tests understanding of adverse effects and drug interactions, focusing on lithium toxicity from sodium depletion by thiazides. The key findings are coarse tremor, vomiting, unsteady gait, and elevated lithium level in a client on lithium and hydrochlorothiazide, indicating toxicity. Holding lithium and notifying the provider is priority to prevent severe neurotoxicity and ensure safety. Administering lithium worsens toxicity; restricting sodium exacerbates it; a snack doesn't address the cause. Assessment of lithium levels and symptoms is crucial. The decision-making principle is to withhold in toxicity. A transferable strategy is to monitor levels when adding diuretics to lithium therapy.
10. A 70-year-old client in the emergency department has chronic obstructive pulmonary disease and takes theophylline. The client started ciprofloxacin yesterday for bronchitis and now has nausea, insomnia, and a heart rate of 126/min with frequent premature ventricular contractions on assessment. What is the nurse's PRIORITY action when noticing a drug interaction?
    Answer: Hold theophylline and notify the provider of suspected elevated theophylline level This question tests understanding of adverse effects and drug interactions affecting theophylline metabolism. The client shows theophylline toxicity symptoms (nausea, insomnia, tachycardia, PVCs) after starting ciprofloxacin, which inhibits cytochrome P450 enzymes that metabolize theophylline, increasing serum levels. Holding theophylline and notifying the provider (B) is the priority because theophylline has a narrow therapeutic index and toxicity can progress to seizures and life-threatening arrhythmias. Administering with food (A) doesn't address the dangerous interaction, encouraging ambulation (C) is unsafe with cardiac arrhythmias, and giving antacids (D) delays critical intervention for toxicity. The nursing priority is recognizing drug interactions that affect medications with narrow therapeutic ranges and intervening before serious complications develop. When fluoroquinolones are prescribed with theophylline, dose reduction is typically required, and nurses must monitor for CNS and cardiac toxicity signs.
11. A 76-year-old client in a long-term care facility takes digoxin for heart failure and furosemide daily. The client reports nausea and seeing yellow halos around lights; assessment shows apical pulse 52/min and irregular. Lab results: potassium 3.1 mEq/L (normal 3.5–5.0). What finding requires IMMEDIATE intervention to prevent further complications?
    Answer: Hold digoxin and notify the provider of suspected digoxin toxicity and hypokalemia This question tests understanding of adverse effects and drug interactions causing digoxin toxicity. The client exhibits classic digoxin toxicity symptoms (nausea, yellow vision, bradycardia) with concurrent hypokalemia (3.1 mEq/L) from furosemide, which increases digoxin's cardiac effects and toxicity risk. Holding digoxin and notifying the provider (B) is the priority because hypokalemia potentiates digoxin toxicity even at therapeutic drug levels, and continuing digoxin could cause life-threatening arrhythmias including complete heart block or ventricular tachycardia. Administering the scheduled dose (A) would worsen toxicity, encouraging fluids (C) doesn't address the dangerous interaction, and teaching about timing (D) delays critical intervention. The nursing priority is recognizing that electrolyte imbalances, particularly hypokalemia, dramatically increase digoxin toxicity risk requiring immediate intervention. When patients take digoxin with potassium-wasting diuretics, nurses must monitor potassium levels closely and recognize visual disturbances as a specific sign of digoxin toxicity.
12. A 69-year-old client with chronic pain takes tramadol and was newly prescribed linezolid for pneumonia in the hospital. Within 24 hours, the client becomes restless with sweating, tremor, and diarrhea; temperature is 38.6°C (101.5°F) and heart rate is 116/min. Which medication should the nurse QUESTION for a client with these symptoms?
    Answer: Linezolid given while the client is taking tramadol This question tests understanding of adverse effects and drug interactions, focusing on serotonin syndrome from linezolid and serotonergic opioids. The key symptoms are restlessness, sweating, tremor, diarrhea, and fever in a client on linezolid and tramadol, indicating serotonin excess. Questioning linezolid with tramadol is appropriate as linezolid has MAOI activity risking syndrome. Ipratropium, pantoprazole, and saline are safe. Assessment of autonomic symptoms is crucial. The nursing process emphasizes interaction screening. A transferable strategy is to avoid serotonergic combinations or monitor closely.
13. A 74-year-old client in a medical-surgical unit takes metoprolol for hypertension and is started on diltiazem for atrial fibrillation rate control. Shortly after the first dose of diltiazem, the client becomes lightheaded; vital signs are BP 88/56 mmHg, HR 38/min. What is the nurse's PRIORITY action when noticing a drug interaction?
    Answer: Hold further doses and notify the provider of symptomatic bradycardia and hypotension This question tests understanding of adverse effects and drug interactions, particularly additive bradycardia and hypotension from beta-blockers and calcium channel blockers. The key findings are lightheadedness, hypotension, and bradycardia in a client on metoprolol and diltiazem, indicating hemodynamic compromise. Holding doses and notifying the provider is priority to prevent syncope or shock. Giving more metoprolol worsens effects; caffeine is inappropriate; reassessing later delays care. Assessment of vital signs is essential. The decision-making principle is to avoid additive AV node suppression. A transferable strategy is to monitor heart rate closely with combined rate controllers.
14. A 62-year-old client on a telemetry unit takes metoprolol for hypertension. The provider administers verapamil for new-onset atrial flutter; 30 minutes later the client reports dizziness and fatigue. Vital signs: HR 38/min, BP 86/50 mm Hg, RR 18/min, SpO2 96% on room air. What finding requires IMMEDIATE intervention to prevent further complications?
    Answer: Hold further doses and notify the provider of symptomatic bradycardia and hypotension The correct action is to hold further doses and notify the provider of symptomatic bradycardia and hypotension. Metoprolol and verapamil have additive negative chronotropic and inotropic effects; at HR 38/min with dizziness and BP 86/50, the client is showing a dangerous drug interaction that can progress to heart block or cardiovascular collapse. Avoiding grapefruit juice and reporting worsening fatigue are important verapamil teaching points, but they do not address the immediate crisis. Reassuring the client that fatigue is expected and continuing cardiac monitoring treats fatigue as a normal side effect when it is actually a warning sign of instability; reassurance alone provides no urgent treatment. Encouraging fluids, placing the client supine, and rechecking blood pressure in 1 hour may support the blood pressure temporarily, but it delays the priority: stopping further medication and getting the provider involved. Therefore, the nurse must halt additional negative inotropic and chronotropic effects and notify immediate.
15. A 66-year-old client with chronic obstructive pulmonary disease uses an albuterol inhaler and is started on propranolol for tremor. At follow-up in an outpatient clinic, the client reports increased shortness of breath and wheezing not relieved by albuterol. Which medication should the nurse QUESTION for a client with these symptoms?
    Answer: Propranolol therapy in a client with COPD using albuterol This question tests understanding of adverse effects and drug interactions, focusing on beta-blockers antagonizing beta-agonists in COPD. The key symptoms are increased shortness of breath and wheezing unrelieved by albuterol in a client on propranolol, due to bronchoconstriction. Questioning propranolol in a COPD client using albuterol is appropriate as nonselective beta-blockers worsen symptoms. Albuterol, corticosteroids, and saline are standard. Assessment of respiratory response is essential. The nursing process emphasizes evaluating therapy efficacy. A transferable strategy is to use cardioselective beta-blockers in respiratory conditions.
16. A 52-year-old client in an outpatient clinic takes metformin for type 2 diabetes and was started on cimetidine for reflux symptoms. The client now reports increasing fatigue and muscle aches; labs show lactate 4.8 mmol/L (normal 0.5–2.2) and creatinine 2.0 mg/dL (normal 0.6–1.3). What finding requires IMMEDIATE intervention to prevent further complications?
    Answer: Lactate elevation with worsening renal function while taking metformin Metformin is eliminated by the kidneys, and cimetidine can reduce its renal clearance. This client's fatigue, muscle aches, elevated lactate (4.8 mmol/L), and rising creatinine (2.0 mg/dL) form the classic picture of metformin accumulation progressing toward metformin-associated lactic acidosis. The finding that requires immediate intervention is the lactate elevation with worsening renal function while the client continues metformin, because further accumulation can precipitate severe acidosis, shock, and multiorgan failure. A fasting blood glucose of 142 mg/dL is only modestly elevated and carries no immediate danger; it does not explain the laboratory abnormalities. Occasional heartburn after spicy foods is a familiar, expected symptom of the reflux condition and is not an urgent threat. A mild headache relieved by rest is a benign, self-limited complaint that would not account for the fatigue, muscle aches, and abnormal labs. Therefore the elevated lactate with declining renal clearance on metformin demands immediate action.
17. A 79-year-old client in a hospital unit takes digoxin for heart failure and was started on furosemide yesterday for fluid overload. This morning the client reports nausea and sees "yellow halos" around lights; apical pulse is 52/min and potassium is 3.1 mEq/L (normal 3.5–5.0). What is the nurse's PRIORITY action?
    Answer: Hold digoxin and notify the provider of possible digoxin toxicity related to hypokalemia. These findings—nausea, yellow halos, bradycardia, and hypokalemia after starting a loop diuretic—are signs of digoxin toxicity; low potassium increases digoxin effect and risk of dysrhythmias. The nurse's priority is to hold the next digoxin dose and notify the provider for evaluation, not to continue or reinforce the cause. Administering the scheduled digoxin dose, even with later potassium rechecking, can worsen toxicity. Restricting fluids and continuing furosemide manages volume overload but leaves hypokalemia untreated and may lower potassium further, increasing toxicity. An antacid treats nausea symptomatically and delays care for the underlying drug interaction. Holding the drug and alerting the provider directly addresses the toxicity and its electrolyte trigger; therefore, that is the correct priority.
18. A 33-year-old outpatient began sertraline 2 weeks ago for depression and continues to take sumatriptan as needed for migraines. Today the client presents to urgent care with agitation, sweating, tremor, diarrhea, and a temperature of 38.9°C (102.0°F); heart rate is 118/min. Which medication should the nurse QUESTION for a client with these symptoms?
    Answer: Sumatriptan taken with sertraline This question tests understanding of adverse effects and drug interactions, focusing on serotonin syndrome from SSRIs and triptans. The key symptoms are agitation, sweating, tremor, diarrhea, and fever in a client on sertraline and sumatriptan, indicating serotonin excess. Questioning sumatriptan taken with sertraline is appropriate as this combination risks serotonin syndrome, requiring reevaluation for safety. Acetaminophen for fever, calcium for heartburn, and loratadine for allergies are benign and unrelated. Assessment involves recognizing neurotransmitter imbalances. The nursing process emphasizes identifying high-risk combinations. A transferable strategy is to educate clients on signs of serotonin syndrome with multiple serotonergic agents.
19. An 81-year-old client in long-term care takes levothyroxine every morning and recently began taking calcium carbonate for osteoporosis. The client reports increasing fatigue and weight gain over the past month; thyroid-stimulating hormone (TSH) is elevated at 9.8 mIU/L (normal 0.4–4.0). What is the nurse's PRIORITY action when noticing a drug interaction?
    Answer: Teach the client to separate levothyroxine and calcium administration by several hours The client's fatigue, weight gain, and elevated TSH suggest levothyroxine is not being absorbed adequately, likely because calcium carbonate binds to it in the gastrointestinal tract. The priority is to teach the client to take these medications at least several hours apart to prevent the interaction. Administering an extra dose is unsafe because it is not ordered and does not address the underlying timing problem. Stopping levothyroxine would worsen the hypothyroidism and is never done without a provider's direction. Increasing dietary iodine does not correct the calcium interference; it targets an unrelated cause and could be harmful. The correct action directly addresses the drug–drug interaction by adjusting administration times.
20. A 66-year-old client in an outpatient clinic takes lisinopril for hypertension and spironolactone for heart failure. The client reports weakness and palpitations; assessment shows irregular pulse. Lab results: potassium 6.2 mEq/L (normal 3.5–5.0), creatinine 1.6 mg/dL (normal 0.6–1.3). What finding requires IMMEDIATE intervention to prevent further complications?
    Answer: Place the client on cardiac monitoring and notify the provider of hyperkalemia The client takes lisinopril, an ACE inhibitor, and spironolactone, a potassium-sparing diuretic; together these strongly increase hyperkalemia risk. A potassium level of 6.2 mEq/L with weakness, palpitations, and an irregular pulse signals that a fatal dysrhythmia may develop. Placing the client on cardiac monitoring and notifying the provider is the immediate priority. Teaching the client to rise slowly addresses orthostatic hypotension but does not treat the life-threatening hyperkalemia or arrhythmia risk. Encouraging potassium-rich foods would raise potassium further and is contraindicated, especially when the client is already taking a potassium-sparing diuretic and an ACE inhibitor. Scheduling a follow-up blood pressure check in 2 weeks delays urgent treatment for a potassium level above 6.0, which can progress to ventricular fibrillation or asystole.

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