Desferrioxamine mesilate

Product: UK SPC via MHRA Products - DESFERRIOXAMINE MESILATE 500 MG POWDER FOR SOLUTION FOR INJECTION OR INFUSION (PL245980020), Noridem Enterprises Ltd; §2: each vial contains desferrioxamine mesilate 500 mg. §4.1 covers chronic iron overload, acute iron poisoning, diagnosis of iron storage disease and certain anaemias, and aluminium overload in dialysis patients. Source: §4.2 posology section 1) 'Treatment of acute iron poisoning' (Adults and children). Desferrioxamine is an adjunct to standard measures generally used in treating acute iron poisoning; it is important to initiate treatment as soon as possible, and the dosage and route should be adapted to the severity of the poisoning. SPC: parenteral treatment should be considered in all symptomatic patients exhibiting more than transient minor symptoms (e.g. more than one episode of emesis or passage of one soft stool); patients with lethargy, significant abdominal pain, hypovolaemia or acidosis; patients with a positive abdominal radiograph showing multiple radio-opacities; and any symptomatic patient with a serum iron level greater than 300 to 350 micro g/dL regardless of TIBC. A conservative approach without desferrioxamine may be considered when serum iron is 300 to 500 micro g/dL in asymptomatic patients, or in those with self-limited, non-bloody emesis or diarrhoea without other symptoms. PREPARATION (SPC): preferably a 10% solution, e.g. dissolve the contents of one 500 mg vial in 5 mL water for injection; the 10% solution can be diluted with Sodium Chloride 0.9%, Dextrose 5%, Sodium Chloride 0.9% with Dextrose 5%, or Ringer's Lactate infusion solutions (these must not be used as the solvent for the dry substance). Only clear pale yellow solutions should be used; opaque, cloudy or discoloured solutions should be discarded. Heparin is pharmaceutically incompatible. Give IV only as a slow infusion; rapid intravenous infusion may lead to hypotension and shock. STOPPING (SPC): chelation should be continued until ALL of the following are satisfied: free of signs and symptoms of systemic iron poisoning (e.g. no acidosis, no worsening hepatotoxicity); ideally a corrected serum iron level that is normal or low (below 100 micro g/dL), though it is acceptable to stop when all other criteria are met if the measured serum iron is not elevated (laboratories cannot measure serum iron accurately in the presence of desferrioxamine); repeat abdominal radiograph shows initial radio-opacities have disappeared; and, if vin-rose coloured urine initially developed, the urine colour has returned to normal (absence of vin-rose urine alone is not sufficient to stop). The serum iron level may rise sharply when iron is released from tissues. Theoretically 100 mg desferrioxamine mesilate can chelate 8.5 mg of ferric iron. SECONDARY INDICATION ON THIS PAGE - CHRONIC IRON OVERLOAD (NOT the dose above; §4.2 section 2, 'Adults and children'): the lowest effective dose should be used; 'The average daily dose will probably lie between 20 and 60 mg/kg/day'; ferritin <2000 ng/mL about 25 mg/kg/day, 2000-3000 ng/mL about 35 mg/kg/day, higher ferritin may require up to 55 mg/kg/day; 'It is inadvisable to regularly exceed an average daily dose of 50 mg/kg/day except when very intensive chelation is needed in patients who have completed growth'; method: slow subcutaneous infusion using a portable pump over 8-12 hours, normally 5-7 times a week (intramuscular injections only when subcutaneous infusion is not feasible); not formulated for subcutaneous bolus injection. Full chronic-overload, aluminium-overload and diagnostic dosing is on the haematology page / full SPC. SCOPE OF RETRIEVED TEXT: the retrieved §4.2 ends mid-sentence in the Elderly paragraph ('...other medicinal product therapy' (see sections'), so nothing after it was retrieved; no intravenous/intramuscular regimen for chronic overload, and no aluminium-overload or diagnostic dosing, is written. Elderly (SPC): clinical studies did not include sufficient numbers of subjects aged 65 and over; dose selection should be cautious, usually starting at the low end of the dosing range. §4.8 is cut off at source after the injection-site reactions.

THESE ARE THE LABEL'S OWN FIGURES for children (SPC §4.2, acute iron poisoning, 'Adults and children'), not scaled adult doses. The SPC gives no age bands and no neonate-specific regimen - do not extend to neonates; verify against a children's formulary. Prolonged therapy in young children (chronic overload, not the dose above): growth must be monitored, and if chelation is started before 3 years of age the mean daily dose should not exceed 40 mg/kg (§4.2/§4.4); three-monthly checks on body weight and height are recommended in children (§4.4).