# A 70-kg client with symptomatic acquired methemoglobinemia after dapsone exposure has an authorized methylene blue dose of 1 mg/kg IV. The vial contains 5 mg/mL. Complete the calculation. > source: MyMerci (mymerci.kr) > url: https://mymerci.kr/pages/nclex_q.php?qn_id=515767&lang=en > language: en > subject: Adverse Effects/Contraindications/Interactions > category: PPT ## Question A 70-kg client with symptomatic acquired methemoglobinemia after dapsone exposure has an authorized methylene blue dose of 1 mg/kg IV. The vial contains 5 mg/mL. Complete the calculation. The calculated dose is ::선택::7 mg35 mg70 mg350 mg. At 5 mg/mL, the nurse should prepare ::선택::1.4 mL7 mL14 mL70 mL. Before administration, verify ::선택::G6PD and serotonergic-medication risksonly the oral temperaturethat sodium chloride is the required diluentthat pulse oximetry is 100 percent. ## Explanation The dose is 70 mg and the volume is 14 mL. Before administration, the nurse must confirm G6PD and serotonergic-medication risks and patent IV access. ## In-depth explanation Quick answer Prepare 70 mg, or 14 mL, after the safety screen. Why this is correct One milligram per kilogram for 70 kg equals 70 mg. At 5 mg/mL, 70 mg divided by 5 mg/mL equals 14 mL. Methylene blue can cause hemolysis in G6PD deficiency and serious serotonin toxicity with serotonergic drugs and opioids. Easy analogy or mental picture Calculate the antidote, then check the two locked doors: G6PD and serotonergic exposure. Memory hook 1 mg/kg; divide milligrams by 5 mg/mL. NCLEX decision rule Calculation accuracy does not replace contraindication and interaction screening. Why the other choices are wrong Pulse oximetry alone can be misleading in methemoglobinemia, and an empiric repeat dose should not be given without reassessment.References 1DailyMed: Dapsone GelMethemoglobinemia warning and cyanosis recognition 2DailyMed: Methylene Blue Injection1 mg/kg dose, 5 mg/mL concentration, G6PD and serotonergic safety warnings ## Clinical scenario Methemoglobinemia antidote check Confirm exposure, co-oximetry, symptoms, G6PD status, serotonergic drugs, renal function, dose, concentration, and venous access. ## Related questions - [A client is admitted to the emergency department after ingesting an unknown amount of acet…](https://mymerci.kr/pages/nclex_q.php?qn_id=362720&lang=en) - [A client with chronic heart failure is prescribed metoprolol 25 mg orally twice daily. Bef…](https://mymerci.kr/pages/nclex_q.php?qn_id=362756&lang=en) - [A 28-year-old client with type 1 diabetes receives regular insulin 6 units and NPH insulin…](https://mymerci.kr/pages/nclex_q.php?qn_id=362792&lang=en) - [A client receives IV vancomycin 1 g every 12 hours for MRSA bacteremia. Before the next do…](https://mymerci.kr/pages/nclex_q.php?qn_id=362833&lang=en) - [A client with bipolar disorder has been taking lithium carbonate 600 mg orally three times…](https://mymerci.kr/pages/nclex_q.php?qn_id=362894&lang=en) - [A nurse is monitoring a client receiving a continuous IV heparin infusion for pulmonary em…](https://mymerci.kr/pages/nclex_q.php?qn_id=363988&lang=en) - [A nurse is preparing to initiate a weight-based continuous IV unfractionated heparin infus…](https://mymerci.kr/pages/nclex_q.php?qn_id=364107&lang=en) - [A nurse is providing discharge teaching to a 65-year-old client newly prescribed warfarin …](https://mymerci.kr/pages/nclex_q.php?qn_id=364872&lang=en) ## Read in another language - [en](https://mymerci.kr/pages/nclex_q.php?qn_id=515767&lang=en) - [ko](https://mymerci.kr/pages/nclex_q.php?qn_id=515767&lang=ko) - [ja](https://mymerci.kr/pages/nclex_q.php?qn_id=515767&lang=ja) - [zh-TW](https://mymerci.kr/pages/nclex_q.php?qn_id=515767&lang=zh-tw) - [vi](https://mymerci.kr/pages/nclex_q.php?qn_id=515767&lang=vi) --- More free questions: [NCLEX-RN Practice](https://mymerci.kr/pages/nclex_bank.php?lang=en) _For study reference only. Always follow current clinical guidelines and your institution’s protocols._