Drugs affecting blood Drugs affecting blood and blood formationand blood formation

Iron Iron

Mucosal block theoryMucosal block theory

Fe reaching the mucosal cells—Fe reaching the mucosal cells—transported into plasma/oxidised to ferric transported into plasma/oxidised to ferric form and complexed with apoferritin to form and complexed with apoferritin to form ferritinform ferritin

Ferrtin is stored in mucosal cellsFerrtin is stored in mucosal cells

Shed after its life span of Shed after its life span of 2-4 days2-4 days

Oral formulations of FeOral formulations of Fe

FerrFerrousous salts are usedsalts are used

CheapCheap

High Fe contentHigh Fe content

Better absorbedBetter absorbed

Adr- gastric irritation and constipationAdr- gastric irritation and constipation

Oral formulationsOral formulations

Ferrous sulphate---20% FeFerrous sulphate---20% Fe

Ferrous gluconate---12%Ferrous gluconate---12%

Ferrous fumarate---33%Ferrous fumarate---33%

Colloidal ferric hydroxide---50%Colloidal ferric hydroxide---50%

Adr of oral FeAdr of oral Fe

Epigastric painEpigastric painHeart burnHeart burnNauseaNauseaVomitingVomitingStaining of teethStaining of teethMetallic tasteMetallic tasteBlotingBlotingColicColicConstipation/diarrhoeaConstipation/diarrhoea

p.e. Fe formulationsp.e. Fe formulations

Fe –dextran-colloidal solutionFe –dextran-colloidal solution containing 50mg elemental Fe/mLcontaining 50mg elemental Fe/mL

Iron-sorbitol-citric acidIron-sorbitol-citric acid complex-50mg fe complex-50mg fe /ml/ml

Fe requirementFe requirement

4.4*body wt (kg) * Hb deficit 4.4*body wt (kg) * Hb deficit (g/dl)(g/dl)

Acute Fe poisoningAcute Fe poisoning

Mostly in infants and childrenMostly in infants and children

10-20 Fe tab10-20 Fe tab

>60mg/Kg B.Wt>60mg/Kg B.Wt

Clinical featuresClinical features

VomitingVomitingAbdominal painAbdominal painHaemetemesisHaemetemesisDiarrhoeaDiarrhoeaLethargyLethargyCyanosisCyanosisDehydrationDehydrationAcidosisAcidosisConvulsionsConvulsionsShockShockCollapse and deathCollapse and death

Pathological lesion isPathological lesion is

1.1. HaemorrhageHaemorrhage

2.2. Inflammation in the gutInflammation in the gut

3.3. Hepatic necrosisHepatic necrosis

4.4. Brain damageBrain damage

treatmenttreatment

1.1. To prevent further absorption of feTo prevent further absorption of fe

2.2. To bind and remove fe already absorbedTo bind and remove fe already absorbed

3.3. Supportive measuresSupportive measures

To prevent frthr absTo prevent frthr abs

1.1. Induce vomitingInduce vomiting

2.2. Perform gastric lavage with sodium Perform gastric lavage with sodium bicarbonatebicarbonate

3.3. Give egg-yolk and milk orallyGive egg-yolk and milk orally —to —to complex fe . Activated charcoal does not complex fe . Activated charcoal does not adsorb feadsorb fe

To bind and remove Fe already To bind and remove Fe already absorbedabsorbed

Desferrioxamine Desferrioxamine

Fe chelating agentFe chelating agent

Injected i.m.Injected i.m.

50mg/Kg repeated 4-12 hourly 50mg/Kg repeated 4-12 hourly

Till serum fe falls below 300micro gram/dlTill serum fe falls below 300micro gram/dl

Alternative-DTPA,calcium edetateAlternative-DTPA,calcium edetate

Supportive Supportive

Diazepam i.v.---if convulsionsDiazepam i.v.---if convulsions

FOLINIC ACID/leucovorinFOLINIC ACID/leucovorin

Methotrexate therapyMethotrexate therapy

Does not need to be reduced by DHFRDoes not need to be reduced by DHFR

Methotrexate inhibits DHFRMethotrexate inhibits DHFR

Toxicity of methotrexate is not Toxicity of methotrexate is not counteracted by folic acid….but by folinic counteracted by folic acid….but by folinic acidacid

Erythropoetin Erythropoetin

Produced by peritubular cells of kidneyProduced by peritubular cells of kidney

Anaemia---rapid secretion of EPO---Anaemia---rapid secretion of EPO---Bone marrowBone marrow

1.1. Stimulates colony forming cells of Stimulates colony forming cells of erythroid serieserythroid series

2.2. Induces haemoglobin formation and Induces haemoglobin formation and erythoblast maturationerythoblast maturation

3.3. Release of reticulocytes in circulationRelease of reticulocytes in circulation

Indication of Epoetin alpha,betaIndication of Epoetin alpha,beta

Anaemia of chronic renal failureAnaemia of chronic renal failure