Respiratory and GI Pharmacology

A 13-year-old boy suffering from acute lymphoblastic leukemia was admitted to the hospital for the third cycle of anticancer therapy, which included high-dose methotrexate. Which of the following drugs should be given to the patient to counteract methotrexate toxicity?

A 2-year-old boy was brought to the emergency department after suffering two episodes of brownish vomit containing pills, followed by a large hematemesis. The mother, who was pregnant, suspected her son had ingested several tablets of her medication. Physical examination showed a lethargic and cyanotic child complaining of abdominal pain. Vital signs were blood pressure 80/50 mm Hg (normal for 2 years 100/65 mm Hg), pulse 130 bpm (normal for 2 years 115 bpm) respirations 30/min (normal at 2 years 24/min). Laboratory values indicated severe metabolic acidosis. Which of the following drugs would be most appropriate for this child?

A 66-year-old woman complained to her physician of bleeding gums. The woman had been receiving her third cycle of chemotherapy for metastatic ovarian cancer. A blood analysis showed the following results: red blood cell count 3.2 × 106/mm3 (normal, female 3.5−5.5 × 106/mm3), mean corpuscular volume 96 fL (normal 80−100 fL), hemoglobin 9 g/dL (normal, female > 12 g/dL), neutrophil count 4600/mm3 (normal 3000−7000/mm 3), platelet count 7000/mm3 (normal 130,000−400,000/mm 3). A hematopoietic agent was administered intravenously. Which of the following drugs would be appropriate for this patient?