Drug Interaction:
Drug Interactions- summary-
Desferrioxmine mesylate +
Gallium 76-
imaging results may distorted. Discontinue defferoxamine 48 hours prior to scintigraphy
Procholorperazine-
concurrent use may lead to temporarory impairment of consciousness
Cardiac disorders with ascorbic acid. Hence oral admin of latter should be done 1 or 2 hours after
deferrioxamine infusion is started. Interferes in estimation of iron binding capacity.
Occassional pain and induration at the injection site
Acute iron intoxification- red urine, generalized erythema (rapid IV use)
Long term therapy- allergic type reactions (cutaneous wheal formation, generalized itching, rash, anaphylactic reaction) blurred vision, cataracts, auditary disturbances, dysuria,abdominal discomfort,diarhea, leg cramps, tachycardia, fever.
SC therapy- localised pain, pruritus, erythema,skin irritation and swelling, which might also
occur in a patient treated for acute intoxification.
Indication:
Acute iron intoxification Chronic iron overload
Adverse Reaction:
On IV injection flushing, urticaria, hypotension, shock, tachypnoea, hypoxaemia, tachycardia, cardiac arrhythmias, convulsions.
On S.C. or I.M. injection, local pain, erythema, swelling, GIT disturbances, dysuria, fever, allergic skin rashes.
Leg cramps on long term therapy.
Reversible visual disturbances and hearing loss. Reduction in the growth of very young children, thrombocytopenia.
Contra-Indications:
Hypersens,severe renal disease or anuria except those on dialysis.
Special precautions:
renal function. Children below 3 years. Increased susceptibility to infection particularly for Yersina species. Concomittant use of ascorbic acid. Severe fungal infections have been reported.
Rapid infusion
flushing of the skin, urticaria, hypotension, and shock have occurred Warnings- Cataracts- occurs rarely with prolonged therapy.
Perform periodic slit
lamp exams on patients treated for chronic iron overload. Otherr ocular disturbances (rare) include - decreased visual acuity, impaired peripheral , color and night vision, retnl apigmentary abnormalities. Disturbances were usually reversible on treatment cessation.
Auditory disturbances
neurotoxicity related auditory abnormalities have been reported including high frequency sensor hearing loss. Pregnancy- Do not use unless clearly needed.
Children
Iron mobilization by dexroxamine is relatively poor in patients < 3 years old with relatively small degrees of iron overload. Withold the drug in such patients unless significant iron mobilization (eg 1mg of iron/day). is demonstrated.
Dosages/ Overdosage Etc:
Indications:
Acute iron intoxification, chromic iron overload.
Dosage:
May administer IM, by continuous SC mini-infusion or slow IV IM rout -prefered. Initially 1g,then 0.5g every 4 hours.
Patient Information:
1. Allergies- Tell your doctor if you have ever had any unusual or allergic reactions to deferoxaime or other related medicines. Also tell your doctor if youn are allergic to any other substances such as foods, preservatives or dyes.
2. Pregnancy- not recommended for women who may become pregnant otr for use during early pregnancy, unless the womens life is in danger from too much iron.
3.Breast feeding- mothers who are taking this medicine and who wish to breast-feed should discuss this with their doctor.
4. Children- deferoxamine is not used for long term treatment of children up to 3 years of age.
5. Elderly- combination of deferoxmine with vitamin C should be used with caution in older patients since this combination may be more likely to vause heart problems in therse patients than in younger adults.
6. Other medicines- tell your doctor if you are taking any of the following- Acsorbic acid - use with deferoxamine may be harmful to body tissues especially in elderly patients
7.Other medical problems- tell your doctor if you have any other medical problems- kidney disease - patients with kidney disease may be more likely to have side effects
8. Missed dose- If you miss a dose of this medicine take it as soon as possible. However if it is almost time for your next dose go back to your regular dosing schedule. Do not double doses.
Pharmacology/ Pharmacokinetics:
Pharmacology:
Chelates iron and prevents it from chemically reacting. Binds free serum iron, iron of ferritin and hemosiderin.
Pharmacokinetics:
Rapidly metabolised by plasma enzymes; exceted in urine. Iron chelates is excreted renally, giving urine a reddish cvolour. Some is excreted in feces via bile.
Interaction with Food:
Not known.
Pregnancy and lactation:
Pregnancy:
Do not use unless required.
Children:
Iron mobilization by dexroxamine is relatively poor in patients < 3 years old with relatively small degrees of iron overload. Withhold the drug in such patients unless significant iron mobilization (eg 1mg of iron/day). is demonstrated.