HEMATINICS

Unit 1.6:                 HEMATINICS                 1 Jam

Drugs that increase haemoglobin level in the blood

Erythropoiesis requires Iron, Vit. B12 and Folic Acid

Deficiency causes Anaemia

Classification:

a.    Iron

i.        Oral Iron (Ferrous fumarate / sulphate

ii.      Parentral Iron (Iron dextran)

b.    Vit. B12 (cyanocobalamin / Hydroxocobolamin)

c.    Folic Acid

A.   Iron

Iron                  Haem + Globin                 Haemoglobin

Absorbed in the duodenum and proximal jejunum

Iron preparations are required in iron deficiency due to :

-          chronic blood loss,

-          pregnancy,

-          abnormalities of the gut,

-          premature birth.

a.   ORAL IRON

Should be given orally (25% are absorbed)

Haemoglobin concentration raise by 100 – 200 mg/100 ml ( 1 – 2 g/l) daily

Normal level (men 13 – 18 g/dl, women 12 – 16 g/dl) should be reached within 1 – 3 months

Continue treatment for further 3 months to replenish Iron store

500 – 1000 mg Ascorbic acid aid to absorption.

No advantage in adding other ingredients except Folic Acid in pregnant mothers

i.             Ferrous Fumerate / Sulphate

Pharmacokinetics

Essenntial components of Haemoglobin

Replenishes Iron stores needed for erythropoiesis

Absorption 5 – 10%

Reduced by many food

Increases by ascorbic acid

Metabolised by incorporated in Hb. In bone marrow

Stored in liver & reticuloendothelial tissues

Unabsorbed excreted in faeces

Indications

Iron deficiency anaemia

Contra indications

Any anaemia other than Iron deficiency anaemia

Primary haemachromatosis

Repeated blood transfusion

Peptic ulcer

Regional enteritis

Ulcerative colitis

Preparation

Tab. Ferous Fumarate 200 mg

Tab. Ferous Sulphate 200 mg

Dose

Adult  400 – 600 mg. daily (devided)

          200 mg daily (Maintenance)

          60 mg. daily (prophylactic)

Child  < 1 year 35 mg tds

          1 – 5 years 70 mg tds

          6 – 12 years 140 mg tds

Side Effects

5 – 20% constipation in elderly

Dark stool

Diarrhoea

Nausea

Epigastric pain

Advice

Take after mel to reduce gastric upset

Do not give with diary product

Mix liquid with juice, give through a straw to prevent teeth staining

2.                Parentral Iron

Given when oral therapy fails

-          Lack of co-operation with oral therapy

-          GI side effects

-          Continuing blood loss or malabsorption

Rapid cure of anaemia is not met by parentral administration of Iron

a.   Iron Dextran

A complex of ferric hydroxide & low molecular weight dextran

Pharmacokinetics

Absorption IM 60 % in 3 days

90% in 1 – 3 weeks

Metabolism clearance reticuloendothelial tissues

Plasma half-life 6 hrs

Indications

Iron deficiency anaemia

Contra indications

Cardiac abnormalities

Severe liver disease

Acute kidney infection

Preparation

Inj. Iron Dextran with 50 mg Iron / ml in 2 mls, 5 mls & 20 mls

Dose

IM      - Deep IM Z tract inj. Technique to avoid local tissue staining

IV      - Total dose infusion

                   Dilute with 500 ml of NS / D5%

                   5 drop / min for 10 min

                   increase progressively 45 – 60 drop / min

Side Effects

Pain

Inflammation & brown colouration at IM site

Cautions / Advice

Risk of anaphylaxis

B.   Vit. B12 (Cyanocobalamin / Hydroxocobolamin)

Microbiologically  derived in meat (liver), eggs & diary product

Average diet contain 5 – 30 mcg

Stored in liver

Indication

Given prophylactically after total gastrectomy or total iliac resection

Hydroxocobalamin retain in blood longer than cyanocobalamin

Dose

Oral        300 mcg / day (macrocytic anaemia

Inj.         Initial 0.25 – 1 mg IM EOD x 1 – 2 weeks

              0.25 mg / week until blood count is normal

              Maintenance 1 mg per month

Preparations

Tab. Cyanocobalamin 10 mg

Tab. Cyanocobalamin 1 mg / amp.

Tab. Cyanocobalamin 0.1 mg / amp

Caution

Not to be given befoe diagnosis

C.   Folic Acid

Richest sources in yeast, liver, kidney & green vegetables

Body stores in liver 5 – 20 mg

Inadequate dietary intake, Phenytoin, Oral Contraceptives, Isoniazide cause folic acid deficiency

Indications

Folate deficient Megaloblastic anaemia due to Poor nutrition, Pregnancy or antiepileptics

Cautions

 Never give alone in Addisonian Pernicious Anemia

-          May participate degeneration of spinal cord

        Not to be use in malignant disease

Preparations

Tab Folic Acid 5 mg

Inj. Folic Acid 15 mg / 5 ml

Dose

Initial  5 mg dly x 4 months

Maintenance 5 mg every 1 – 7 days

Child       < 1 year 500 mcg / kg dly

              Over 1 year as adult dose