The dose of desferoxamine used is 15 mg/kg per hour.
dose of desferoxamine per hour =
= 15 * (body weight in kilograms)
Limitations of other methods for monitoring chelation therapy:
(1) serum iron levels: Serum levels may be unreliable in a person is being treated with desferoxamine since it interferes with assays on most analyzers. It does not interfere with atomic absorption or plasma emission spectrography, but these are not used in most laboratories.
(2) urine color: The ferrioxamine formed from iron and desferoxamine makes the urine reddish-orange. Treating the patient until the urine is no longer colored is inexact and subjective.
Yatscoff et al tested urine, starting 2 hours after chelation therapy started. The urine was pretreated to release iron from ferrioxamine with 2% volume to volume thioglycolic acid and 10% volume to volume trichloroacetic acid.
Treated samples were tested for:
(1) urine iron in µmol/L
(2) urine creatinine in mmol/L
ratio of urinary iron to creatinine =
= (urine iron in µmol/L) / (urine creatinine in mmol/L)
Therapy is continued as long as the ratio is > 12.5
