Haematinics These are substances required in the formation of blood, and are used for treatment of anaemias.
Anaemia occurs when the balance between production and destruction of RBCs is disturbed by:
(a) Blood loss (acute or chronic)
(b) Impaired red cell formation due to:
• Deficiency of essential factors, i.e. iron,
vitamin B12, folic acid.
• Bone marrow depression (hypoplastic anaemia), erythropoietin deficiency.
(c) Increased destruction of RBCs (haemolyticanaemia)
In this chapter essential factors required for normal formation or pigmentation of RBCs will be covered
Hematinics, coagulants and anticoagulants.
c. Fibrinolytics and anti-platelet drugs
d. Plasma volume expanders
2. Pharmacology of drugs acting on urinary system
Distribution of iron in body Iron is an
essential body constituent. Total body iron in an adult is 2.5–5 g (average 3.5 g). It is more in men (50 mg/kg) than in women (38 mg/kg). It is distributed into:
Haemoglobin (Hb) : 66%
Iron stores as ferritin and : 25%
Myoglobin (in muscles) : 3%
Parenchymal iron (in enzymes, etc.) : 6%
Haemoglobin is a protoporphyrin; each molecule having 4 iron containing haeme residues. It has 0.33% iron; thus loss of 100 ml of blood (containing 15 g Hb) means loss of 50 mg elemental iron. To raise the Hb level of blood by 1 g/dl about 200 mg of iron is needed. Iron is stored only in ferric form, in combination with a large protein apoferritin.
aggregates Apoferritin + Fe3+ FerritinHaemosiderin
(not reutilized)Ferritin can get saturated to different extents; at full saturation it can hold 30% iron by weight.The most important storage sites are reticuloendothelial (RE) cells. Parenchymal iron occurs as prosthetic group in many cellular enzymes—