Iron deficiency anaemia Flashcards
name 2 possible serious underlying causes of anaemia
gastric erosion
GI cancer
What to do if pt has confirmed iron deficiency anaemia
treatment with iron prep initiated
exclude any serious underlying causes e.g. gastric erosion, GI cancer - but do not delay iron treatment whilst waiting investigations
When is prophylaxis with iron prep important (6)
malabsorption, menorrhagia, pregnancy, after subtotal or total gastrectomy, in haemodialysis patients, and in the management of low birth-weight infants such as preterm neonates.
true or false - prophylaxis with iron prep may be appropriate in haemodialysis pt
true
true or false - prophylaxis with iron prep may be appropriate after subtotal or total gastrectomy
true
iron salts should only be given via this route unless good reasons for using another route
by mouth
is there any differences in efficacy of absorption of iron between the different ferrous salts
only marginal differences between one another in efficiency of iron absorption
choice of preparation (which iron salt) is usually decided by … (2)
incidence of SE
cost
is Hb regeneration rate affected by the type of salt used?
It is little affected by the type of salt used as long as sufficient iron is given
Low or high doses or iron salts initially recommended?
lower initial daily doses are recommended, as these may be just as effective as higher doses, with lower rates of SE and better compliance
monitoring for Hb response to oral iron & how long to continue
- monitor in the first 4 weeks for Hb response to oral iron
- continue treatment for around 3 months after normalisation of Hb conc
- dose of oral iron salts can be increased if therapeutic response is slow and treatment is tolerated
Some oral preparations of iron contain ascorbic acid. Why?
To aid absorption of the iron but the therapeutic advantage of such preps is minimal and cost may be increased
Use of MR preps of iron
- licensing
- use
- how they work
- SE
licensed for OD dosage
but have no therapeutic advantage
should not be used
formulated to release iron gradually
low incidence of SE but this may be due to small amounts of iron available for absorption as the iron is carried past the 1st part of the duodenum into an area of the gut where absorption may be poor
Parenteral iron generally reserved for the following ..
when oral therapy is unsuccessful bc pt cant tolerate oral iron
or pt does not take it reliably
or if there is continuing blood loss, or in malabsorption
Parenteral iron role in chemo-induced anaemia
Parenteral iron may also have a role in the management of chemotherapy-induced anaemia, when given with erythropoietins, in specific patient groups
many patients with chronic renal failure who are receiving haemodialysis (and some who are receiving peritoneal dialysis) may require…
iron by the intravenous route on a regular basis
Parenteral iron does not produce a faster haemoglobin response than oral iron provided that the oral iron preparation is taken reliably and is absorbed adequately. The exception to this is when it is used for ….
patients with severe renal failure receiving haemodialysis
Doses of parenteral iron
Depending on the preparation used, parenteral iron is given as a total dose or in divided doses.
Common SE For all oral iron (4)
constipation
diarrhoea
GI Discomfort
nausea
SE of iron - constipation
Iron can be constipating and occasionally lead to faecal impaction.
SE of iron - diarrhoea
Oral iron, particularly modified-release preparations, can exacerbate diarrhoea in patients with inflammatory bowel disease; care is also needed in patients with intestinal strictures and diverticular disease.
T or F - iron can exacerbate diarrhoea in pt with IBD
yes
monitoring of pt parameters
Monitor haemoglobin concentration within the first 4 weeks of treatment, then regularly thereafter to assess response (e.g. every 4 weeks). Once haemoglobin is within the normal range, treatment should be continued for around a further 3 months to replenish the iron stores. After treatment, monitor blood count periodically (e.g. every 6 months) to detect recurrence.
Once Hb is within the normal range, treatment should be continued for a further …… months to replenish the iron stores
3 months
After iron treatment, should you monitor the blood count to detect recurrence of iron-deficiency anaemia
Monitor it periodically e.g. every 6 months to detect recurrence
How to take oral iron
It is recommended to take iron on an empty stomach to allow for better absorption, although it can be taken after food to reduce gastro-intestinal side-effects if necessary.
T or F - recommended to take iron on empty stomach to allow for better absorption
true
can be taken after food to reduce GI SE if needed
Cautions for all oral iron -
high doses in elderly
no evidence of enhanced iron absorption above these doses
Iron salts poisoning - what are the symptoms
nausea, vomiting, abdominal pain, diarrhoea, haematemesis, and rectal bleeding
Hypotension and hepatocellular necrosis can occur later
These symptoms indicate severe iron salts poisoning
Coma, shock, and metabolic acidosis
iron salts poisoning - mortality is reduced by intensive and specific therapy with the following drug which chelates iron
desferrioxamine mesilate
When to give desferrioxamine mesilate in relation to serum-iron conc measurements
- measure serum-iron conc as an emergency and IV desferrioxaminde is given to chelate absorbed iron in excess of expected iron binding capacity
- in severe toxicity, give it IV immediately without waiting for result of serum-iron measurement
Iron interacts severely with this antipsychotic. What is the drug and what is the interaction?
Clozapine can cause constipation, as can Iron ; concurrent use might increase the risk of developing intestinal obstruction. Manufacturer advises caution.
Iron has an interaction with this abx drug class. Which drug class & what is the interaction
Macrolides e.g. demeclocycline, doxycycline, eravacycline, lymecycline, minocycline, oxytetracycline, tetracycline
Oral iron decreases the absorption of these oral drugs. They should be taken 2-3 hours after iron
Iron interactions with antacids, calcium carbonate,
oral Antacids, calcium carbonate decrease the absorption of oral Iron. Manufacturer advises iron should be taken 1 hour before or 2 hours after antacids.
Iron interactions with parkinsons drugs (3)
entacapone is predicted to decrease absorption of oral iron. separate administration by at least 2 hrs
levodopa, carbidopa decreases absorption of oral levodopa. separate administration
iron interacts with this class of abx
hint - the class has a lot of MHRA alerts and should only be used if nothing else can be used
quinolones
ciproflox, levoflox, moxiflox, ofloxacin.
oral iron decreases exposure to these oral abx, separate adminstration by at least 2 hours
interaction with Ibandronate
oral Iron is predicted to decrease the absorption of oral Ibandronate. Manufacturer advises Ibandronate should be taken 1 hour before or 6 hours after iron.
interaction with Levothyroxine
oral Iron decreases the absorption of oral Levothyroxine. Manufacturer advises separate administration by at least 4 hours.
interaction with Risedronate
oral Iron decreases the absorption of oral Risedronate. Manufacturer advises separate administration by at least 2 hours.
interaction with zinc
oral Zinc is predicted to decrease the efficacy of oral Iron and oral Iron is predicted to decrease the efficacy of oral Zinc. Manufacturer makes no recommendation.
What is it
the reduction of red blood cell production due to low iron stores in the body.
