A 16-year-old boy comes to the emergency department due to a day of severe left thigh pain. He was diagnosed with sickle cell disease during childhood. The boy has had several episodes of unbearable pain in his abdomen, thighs, and lower back that have required 6 separate hospitalizations for pain management and intravenous fluids. Temperature is 36.7 C (98 F), blood pressure is 120/80 mm Hg, pulse is 100/min, and respirations are 16/min. Pulse oximetry shows an oxygen saturation of 97%. Examination shows an uncomfortable-appearing boy. Lungs are clear to auscultation. The left thigh is tender to palpation but has no erythema or swelling. The patient is able to bear weight and has no pain elsewhere. Adequate hydration and analgesics are administered, with improvement of symptoms. On discharge from the hospital, the patient's hematologist counsels him about starting a first-line medication to decrease the frequency of his pain crisis. What is the most common potential side effect of this first-line medication?

Question

A 16-year-old boy comes to the emergency department due to a day of severe left thigh pain.  He was diagnosed with sickle cell disease during childhood.  The boy has had several episodes of unbearable pain in his abdomen, thighs, and lower back that have required 6 separate hospitalizations for pain management and intravenous fluids.  Temperature is 36.7 C (98 F), blood pressure is 120/80 mm Hg, pulse is 100/min, and respirations are 16/min.  Pulse oximetry shows an oxygen saturation of 97%.  Examination shows an uncomfortable-appearing boy.  Lungs are clear to auscultation.  The left thigh is tender to palpation but has no erythema or swelling.  The patient is able to bear weight and has no pain elsewhere.  Adequate hydration and analgesics are administered, with improvement of symptoms.  On discharge from the hospital, the patient's hematologist counsels him about starting a first-line medication to decrease the frequency of his pain crisis.  What is the most common potential side effect of this first-line medication?

Quizplus · Accepted Answer

11ec25c8_d42a_46e6_bc81_e74778864e72_MD0003_00 The hallmark of sickle cell disease (SCD) is recurrent, acute, painful episodes due to vaso-occlusion. Acute management consists of hydration and analgesia with nonsteroidal anti-inflammatory drugs and opioids. Hydroxyurea is indicated in patients with frequent pain crises, history of acute chest syndrome, and/or severe symptomatic anemia. The major beneficial effect of hydroxyurea is to increase fetal hemoglobin. Sickled hemoglobin is therefore proportionally decreased, resulting in reduced polymerization of red blood cells (RBCs) and fewer episodes of vaso-occlusion. Hydroxyurea also decreases the risk of acute chest syndrome and the need for blood transfusions. The primary dose-limiting side effect of hydroxyurea is myelosuppression (eg, neutropenia, anemia, thrombocytopenia), but it is otherwise relatively safe. (Choice A) Patients with SCD commonly develop renal disease due to sickling of RBCs in the renal medulla. Hydroxyurea is a rare cause of acute kidney injury (AKI), and patients with SCD presenting with AKI should be evaluated for alternative etiologies of AKI (eg, use of nonsteroidal anti-inflammatory drugs, papillary necrosis). (Choice B) Iron overload can also occur as a result of chronic RBC transfusions. Chronic iron overload can result in hemosiderosis-related cirrhosis and cardiomyopathy, and iron chelation therapy should therefore be used in patients with SCD who require chronic transfusion therapy for severe symptomatic anemia. (Choice D) Osteonecrosis in patients with SCD refers to the chronic loss of cartilage and bony tissue at the femoral heads due to avascular necrosis. Patients have progressive hip pain on weight-bearing. Hydroxyurea has no known negative effects on bone formation or growth. (Choice E) Patients with SCD are at increased risk for stroke. Hydroxyurea has been shown to improve transcranial Doppler ultrasound flow (a corollary for risk of stroke in patients with SCD). Hydroxyurea also decreases the risk of recurrent strokes in patients with SCD. (Choice F) Although blood banks routinely screen all products for disease, patients who require blood transfusions are at a slightly increased risk of acquiring viral infections (eg, HIV, hepatitis C). The neutropenia associated with hydroxyurea should not increase the risk of viral infection. Educational objective: Hydroxyurea, which works by increasing fetal hemoglobin levels, is indicated in patients with sickle cell disease who have frequent vaso-occlusive crises. It is a relatively safe therapy with a dose-limiting side effect of myelosuppression (neutropenia, anemia, thrombocytopenia). References: National Institutes of Health Consensus Development Conference statement: hydroxyurea treatment for sickle cell disease. (http://www.ncbi.nlm.nih.gov/pubmed/18458271) Hydroxyurea for the treatment of sickle cell disease: efficacy, barriers, toxicity, and management in children. (http://www.ncbi.nlm.nih.gov/pubmed/22517797)

A 16-Year-Old Boy Comes to the Emergency Department Due to a Day