A 48-year-old woman with rheumatoid arthritis presents with severe oral ulcers, dysphagia, and fatigue. She mistakenly took methotrexate 25 mg daily for 2 weeks instead of weekly. Vital signs: BP 128/82, HR 102, RR 18, Temp 37.2°C, SpO2 98% on room air. Laboratory studies reveal WBC 2.1 K/μL, hemoglobin 9.8 g/dL, and platelets 85 K/μL. Mucous membranes show extensive ulceration. No hepatomegaly is appreciated on examination. Which medication is indicated as rescue therapy?
- A)Hydroxocobalamin
- B)LeucovorinGABARITO
- C)Pyridoxine
- D)Atropine
- E)Protamine sulfate
Explicação
Methotrexate inhibits dihydrofolate reductase, impairing thymidylate and purine synthesis. Leucovorin, a reduced folate, bypasses this blockade and is used as rescue therapy in toxicity. Ver explicação completa e trilha adaptativa →