Urinary iron excretion induced by intravenous infusion of deferoxamine in ß-thalassemia homozygous patients

Abstract

The purpose of the present study was to identify noninvasive methods to evaluate the severity of iron overload in transfusion-dependent ß-thalassemia and the efficiency of intensive intravenous therapy as an additional tool for the treatment of iron-overloaded patients. Iron overload was evaluated for 26 ß-thalassemia homozygous patients, and 14 of them were submitted to intensive chelation therapy with high doses of intravenous deferoxamine (DF). Patients were classified into six groups of increasing clinical severity and were divided into compliant and non-compliant patients depending on their adherence to chronic chelation treatment. Several methods were used as indicators of iron overload. Total gain of transfusion iron, plasma ferritin, and urinary iron excretion in response to 20 to 60 mg/day subcutaneous DF for 8 to 12 h daily are useful to identify iron overload; however, urinary iron excretion in response to 9 g intravenous DF over 24 h and the increase of urinary iron excretion induced by high doses of the chelator are more reliable to identify different degrees of iron overload because of their correlation with the clinical grades of secondary hemochromatosis and the significant differences observed between the groups of compliant and non-compliant patients. Finally, the use of 3-9 g intravenous DF for 6-12 days led to a urinary iron excretion corresponding to 4.1 to 22.4% of the annual transfusion iron gain. Therefore, continuous intravenous DF at high doses may be an additional treatment for these patients, as a complement to the regular subcutaneous infusion at home, but requires individual planning and close monitoring of adverse reactions.

Consequences and costs of noncompliance with iron chelation therapy in patients with transfusion‐dependent thalassemia: a literature review

“…Published studies that have reported the degree of compliance with ICT are summarized in Table 1. These studies include seven that examined deferoxamine only, 1,3,11‐15 six that examined deferiprone only, 16‐21 and five that compared deferoxamine and deferiprone 4,22‐24 . No published studies reporting compliance with deferasirox were identified.…”

“…Richardson and associates 13 used vial counts to assess compliance for 76 Australian patients and reported compliance of more than 90 percent in 61 percent, 50 to 90 percent in 22 percent, and less than 50 percent in 17 percent of patients, implying a mean compliance of 77 percent. Boturao‐Neto and coworkers 14 examined compliance among 26 Brazilian patients with patient‐family self‐reports and reported that 65 percent took 80 percent of their prescribed doses, suggesting mean compliance of 73 percent 14 . Over all cohort studies of deferoxamine only, mean compliance estimated in this fashion ranges from 59 to 78 percent.…”

Current Status in Iron Chelation in Hemoglobinopathies

“…Several papers have been published on the degree of compliance with iron chelation therapy (ICT). Seven studies examined deferoxamine only, [22,[96][97][98][99][100][101], six examined Deferiprone only [22,55,56,[102][103][104][105] and five compared Deferoxamine and Deferiprone [57,59,62,106]. Five studies were based on Italian patients and five were based on patients in Canada.…”

Compliance of deferoxamine injection in beta‐thalassaemia major patients in Iran

“…In a cohort study by Gabutti & Piga (1996) assuming uniformity between categories, compliance would be 64%. Also, mean compliance in other cohort studies reported was Beratis 67% (Beratis, 1989), Richardson and associates 77% (Richardson et al , 1993) and Boturao‐Neto 73% (Boturao‐Neto et al , 2002). Overall cohort studies of DFO indicate a mean compliance ranging between 59 and 78% (Delea et al , 2007).…”