Desferrioxamine

Question 1

What is desferrioxamine?

Answer 1

natural product isolated from streptomyces pilosus. Forms iron complexes.
Used as cheklating agent, espeically in mezylate form.

Question 2

What class of drugs does desferrioxamine belong to?

Answer 2

detoxifying agents

antidotes

Question 3

What are drugs are in the same class as desferrioxamine?

Answer 3

atropine sulfate
acetylcysteine
nalozone hydrochloride
penicillamine

Question 4

What is desferrioxamine indicated for?

Answer 4

acute iron or Aluminium toxicity in certain patients.
treatment of chronic iron overload
Used to treat certain patients with anemia who must receive many blood transfusions.

Question 5

What is the dose of desferrioxamine used for treating iron toxicity?

Answer 5

subcutaneous infusion

20-50mg/kg daily over 8-12 hours, 3-7x/week (adult)

Question 6

What is the mechanism of action of desferrioxamine?

Answer 6

Binds to trivalent ferric iron with strong affinity to form ferrioxamine. This is a stable complex which is eliminated via kidneys.

Question 7

What are the main PK or PD parameters with desferrioxamine use?

Answer 7

PK:
Rapidly absorbed after IM or SC admin, but poorly absorbed from GIT in the presence of in tact mucosa.

Less than 10% bound to serum proteins in vitro

Mainly metabolised in plasma. hepatic metabolism minimal.

some excretion in bile.

second phase half life of 6 hours.

Question 8

What are the precautions associated with desferrioxamine use?

Answer 8

risk of growth retardation with excessive doses
aluminium related encepalopathy
pregnancy class B3: teratogenic in animal studies
Use with caution if breast feeding. insufficient data.
monitor cardiac function, urinary FE excretion or serum ferritin.

Question 9

What are the contraindications associated with desferrioxamine use?

Answer 9

known hypersensitivity to active substance, except where successful desensitisation makes treatment possible

Question 10

What are the adverse reactions associated with desferrioxamine use?

Answer 10

nausea
vomiting
abdominal pain
headache
pyrexia
growth retardation
bone disorders
hearing disturbanes
injection site reactions

Rare: diarrhoea, hepatic impairment, hypotension, anaphylaxis

Question 11

What are the main drug interactions associated with desferrioxamine use?

Answer 11

concurrent treatment with prochlorperazine may lead to termporary impairment of consciousness.

combined treatment with high doses of vitamin C (>500mg/day) associated with impairment of cardiac function

avoid levomepromazine- advised by manufacturer

Question 12

What are the alarm bells associated with desferrioxamine use?

Answer 12

may cause growth retardation, bone disorders, eye and ear problems

Question 13

What monitoring is involved with desferrioxamine use?

Answer 13

Have an eye and ear examination before treatment AND at 3 month intervals during treatment.

monitor body weight and height in children at 3 month intervals