Anemia Theraputics

Question 0

Oral Iron: types, MOA, Sx, enhancers, inhibitors

Answer 0

• ferrous sulfate, ferrous gluconate, ferrous fumarate
• MOA: conversion to Fe2+ for absorption; reticulocytes in days, normalizes in 2 Mo
• Fe def anemia
• Sx: GI upset, dark stools, constipation, NVD,
  ~ OD is dangerous and can be lethal in kids: NV, CV collapse
  E-lyte imbalance
• absorption enhanced by: vitamin C
• absorption inhibited by: Ca, Mg, Al, tetracyclines, PPIs, cholestyramine, food (Fe inhibits absorption of aformentioned)
• separate interacting drugs by ~ 2 hrs

Question 1

Blood transfusion (Indications, risks, benefits)

Answer 1

• avoid if possible
• indicated in rapid Hb decline
• benefits: rapid correction, works
• risks: iron overload, hyperkalemia, caogulopathies, immune rxns, infxns, allosensitization

Question 2

Parenteral Fe: iron Dextrans (enfed better one, dexferim)

Answer 2

• biggest molecular particle
• colloidal Fe nanoparticle
• Hb restored much more quickly
• indicated: intolerance to oral supp. Poor absorption, non-adherence, decreases need for transfusion, hemodialysis PTs
• Sx: BLACK BOX: anaphylaxis; can worsen active infxn, hypersensitivity, Fe overload, infusion site rxn, other normal rxns
• cheaper than other forms, slowest release, long 1/2life

Question 3

Parenteral Fe: Na-Fe gluconate complex

Answer 3

• colloidal Fe nanoparticle
• Hb restored much more quickly
• indicated: intolerance to oral supp. Poor absorption, non-adherence, decreases need for transfusion, hemodialysis PTs
• less risk of anaphylaxis, shortest 1/2life

Question 4

Parenteral Fe: Iron sucrose

Answer 4

• colloidal Fe nanoparticle (middle weight colloid particle)
• Hb restored much more quickly
• indicated: intolerance to oral supp. Poor absorption, non-adherence, decreases need for transfusion, hemodialysis PTs
• best SE profile, least risk of anaphylaxis

Question 5

Parenteral Fe: Fermoxytol

Answer 5

• colloidal Fe nanoparticle
• Hb restored much more quickly
• indicated: intolerance to oral supp. Poor absorption, non-adherence, decreases need for transfusion, hemodialysis PTs
• highest risk if anaphylaxis, MRI contraindicated w/in 3 mo.
• don’t use

Question 6

Cyanocolobamin

Answer 6

• Megaloblastic B12 deficiency anemia
• MOA: Cofactor for reactions forming THF methionine metabolization of L-methylmalonyl-CoA
• IM in neuro Sx are present: oral/intranasal maintenance
• rapid RBC correction may cause fluid overload, hypokalemia
• BM in 3 day, strength recovered in 7, neuro Sx diminish in 30, life long Tx

Question 7

Hydrocolobamin

Answer 7

• Megaloblasticanemia
• MOA: Cofactor for reactions forming THF methionine metabolization of L-methylmalonyl-CoA
• not for B12
• IM in neuro Sx are present: oral/intranasal maintenance
• rapid RBC correction may cause fluid overload, hypokalemia
• BM

Question 8

Folic acid

Answer 8

• inactive THF precursor
• MOA: essential donor of methyl group for AAs, purines, DNA
• Folate anemia
• prevention of chronic methotrexate toxicity, NTDs
• No Sx at replacement doses
• reticulocytes -> 7 days, HCT -> 1 mo, Tx usually 4 mo

Question 9

Leucovorin

Answer 9

• active THF derivative
• for severe folate antagonism of methotrexate
• 5FU antineoplastic synergy
• No Sx at replacement doses

Question 10

EPO, Alfa and darbopoetin

Answer 10

• MOA: binds EPO receptor -> increase RBC prolif/diff
• used in anemia 2^ to chronic kidney disease
• BLACK BOX: increase risk of MI, stroke, VTE, Tumor,
• Sx: HTN, pure red cell aplasia due to anti-EPO Abs; trt with peginsatide
• not started until Hb < 10g/dl, retic recovery in days, full effect in 4 weeks

Question 11

Pegintaside

Answer 11

• MOA: EPO memetic, supports EPO production
• prevents transfusion
• BLACK BOX: increase risk of MI, stroke, VTE, Tumor,
• tx lifelong

Question 12

Itrogenic Aplastic anemia causes

Answer 12

• chemo
• chloramphenicol
• carbamazepine
• phenytoin
• HSNs
• trt: immunosuppressants, anti thymocyte globulin, HPSC transplant

Question 13

Itrogenic G6PDH Deficiency causes

Answer 13

• sulfa drugs
• nitrofurantoin
• phenazopyridine
• dapsone
• trt by removing oxidative stress

Question 14

Itrogenic immune hemolytic anemia trt and causes

Answer 14

• rare; support, discontinue offending agent, symptomatic
• PCN
• anti-inflammatoriesopa
• anti-neoplastics
• methyl dopa
• cefotelan

Question 15

Deferoxamine

Answer 15

• iron chelators: iron overload
• MOA: hexidentate structure: 1-1 binding
• indicated when ferritin > 1000 ng/mL
• Cind: renal failure
• Sx: red/orange urine, murcomycosis, growth problems, skeletal dysplasia
• advantages: increases long term survival, redux iron induced heart disease
• disadvantages: poor bioavailability and short 1/2 life, compliance issues

Question 16

Deferiserox

Answer 16

• tridentate structure
• MOA: 2:1 iron binding
• advantages: good oral availability, longer 1/2life, well tolerated
• disadvantages: no long term efficacy data, req higher doses
• Cind: renal failure, tcytopenia and neoplasia
• Sx: NV, rash, renal hepatic dysfunction, sensory toxicity

Question 17

Iron chelator considerations; monitoring, maintenance dose

Answer 17

• monitor liver iron content via MRI
• ## maintain less than 1000 ng/dL

Question 18

Itrogenic Pure red cell aplasia trt

Answer 18

EPO stimulators induce anti EPO Ab

Question 19

Megaloblastic anemia with neuro symptoms

Answer 19

• cyanocolobamin (1st line)

- hydroxycolobamin IM

Question 20

Prevention of chronic methotrexate toxicity

Answer 20

• folate

Question 21

Itrogenic hyperkalemia

Answer 21

• May be a result of blood transfusions

Question 22

Itrogenic Hypokalemia

Answer 22

• cyanocolobamin, rapid b12 correction -> fluid accumulation