Anemia Drugs PDF

L1 pharma Drugs used in treatment of anemia ❖ Anemia It is defined as deficient numbers of circulating red blood cells or low total hemoglobin content per unit of blood volume. ❖ Classification of anemia according to cause: 1-Deficiency anemia: o Iron deficiency anemia (hyp...

L1 pharma Drugs used in treatment of anemia ❖ Anemia It is defined as deficient numbers of circulating red blood cells or low total hemoglobin content per unit of blood volume. ❖ Classification of anemia according to cause: 1-Deficiency anemia: o Iron deficiency anemia (hypochromic – microcytic) o Vit B12 and folic acid deficiency anemia (macrocytic anemia) 2- Aplastic anemia: o The body fails to produce blood cells which may be primary (idiopathic) and secondary to some drugs as anticancers- antithyroid. 3-Hemolytic anemia: It means excessive blood destruction due to: o Congenital anomalies of RBCs as congenital spherocytosis o Hemolytic disease of newborns. ❖ Iron deficiency anemia Actions of iron (importance): 1-It is essential metallic component of haem, the responsible for the bulk of O2 transport in the blood. 2-It also present in iron containing enzymes in mitochondria. pharmacokinetic Absorption : o About 10% of ingested iron is absorped. o Iron is absorped mainly from small intestine (duodenum) in ferrous state Factors increase absorption: Factors decrease absorption o Gastric acidity. o Antacids o Ascorbic acid o Tannic acid o Malabsorption syndrome Transport and 1. It is oxidized in mucosal cells to ferric form. storage: 2. Iron travels through blood (bound to transferrin), and ends in bone marrow where it is involved in red cells formation. Elimination : Small amount of iron are lost with sweet, saliva, (0.5 mg / day) 1|Page  L1 pharma ❖ Causes of iron deficiency anemia (indication of iron therapy) 1) Decrease intake:. poor diet or malabsorption. 2) Increase demand: pregnancy 3) Excess blood loss. Iron preparation Oral prepeation Parental iron Indication o Given after meals to avoid GIT o Inability to tolerate or absorb oral irritation for 3-6 months iron. o Server anemia or severe blood loss Forms o ferrous sulphate o iron dextran (IM-IV) o ferrous gluconate o iron dextrin(IV) o ferrous fumarate o iron sorbitol citric acid (IM) Side effects o GIT upset: 1- Anaphylaxis (minimal with iron gluconate) 2- Local pain and tissue stating with o Constipation or diahrea. IM injection o Black stools 3- headache- bronchospasm- o Black discoloration of teeth. tachycardia. Iron toxicity Acute toxicity Chronic toxicity Cause o Common in children due to accidental 1-Excess iron absorption: ingestion of iron tablets (hemochromatosis). 2-Excess blood transfusion. Manifestation o Abdominal pain- vomiting-diahrea o Excess iron deposition in bloody stool. liver-pancrease-skin o Shock-dyspnea o metabolic acidosis-coma and death. Treatment o Gastric lavage by phosphate or carbonate o One unit of the blood is solution to form insoluble complex. removed every one week o Desferrioxamine (Desferal): it is iron until excess iron is chelating agent (IM or IV infusion) removed (phlebotomy). o Systemic treatment: as fluids for o Desferrixoxamine when dehydration phlebotomy can not be performed. 2|Page  L1 pharma ❖ Megaloblastic anemia Vit B12 Actions of vit B12: 1. Essential for hemopoiesis. 2. It is important for DNA synthesis. 3. Myelination of nerue fibres in CNS. Pharamacokinetics: Absorption o Depends on prescence of intrinsic factors. o Vit B12 and intrinsic factor combination is absorbed from ileum. o Drugs interfere with absorption: - colchicine- antiepileptic drug -metformin. 2-Distribution and Bound to alpha (transcobalamine I) and beta globulin (transcobalamine II) storage: then stored in liver and kidney. 3-Excretion: bile and urine. Causes of vit b12 deficiency: 1-Decrease intake 2-Increase demands: pregnancy 3-Decrease intrinsic factor (autoimmune atrophic gastritis-gastrectomy) 4-Terminal illeum disease Manifestation of vit B12 deficiency: o Blood: megaloblastic anemia (macrocytic anemia) o GIT: Glossitis and diahrreha o CNS: subacute combined degeneration of spinal cord. Posterior column degeneration leads to deep sensory loss. Pyramidal tract degeneration leads to paraplegia Peripheral neuritis. 3|Page  L1 pharma Preperations of Vit B12 o Cyancobalamine: IM o Hydroxocobalamine: IM Uses of : Vit B12 1. Megaloblastic and pernicious anemia 2. Peripheral neuropathy. 3. Cyanide poisoning (Hydroxocobalamine). ❖ Pernicious anemia: o It occurs due to atrophy of the gastric mucosa that becomes unable to secreted intrinsic factor which is necessary for absorption of Vit.B12. o it is treated by cyanocobalamine (1000 ug IM daily for 2 weeks then once / week for life. Folic acid Actions : 1. Synthesis of DNA as it is essential for synthesis of purine ring 2. Essential with Vit B12 for erythropoiesis Causes of folic acid deficiency: 1-Decrease intake 2-Decrease absorption 3-Increase demands (pregnancy-children) 4-Drugs: methotrexate Manifestations of folic acid deficiency: o Megaloblastic anemia Uses of folic acid: 1-megaloblastic anemia o There is deficiency of vit B12 and folic acid o If the patient has deficiency of Vit B12 and folic acid both agents should be given andvit B12 must be used before folic acid. 4|Page  L1 pharma 2-Malabsorption syndrome 3-Pregnancy 4-To prevent toxicity of antifolate drugs as o Methotrexate o oral contraceptive (decrease folic acid absorption) o phenytoin ( increase folic acid metabolism). ❖ Aplastic anemia Management : 1. Stop the responsible drug. 2. Give fresh blood transfusion. 3. Penicillin to infection. 4. Corticosteroid to inhibit immune reaction. 5. Hematopoietic growth factors. 6-Stem cells transplantation in severe or resistant cases ❖ Heamopiotic growth factors o They are glycoprotein hormones that regulate the proliferation and differentiation of hematopoietic progenitor cells in the bone marrow.They include: 1-Erythropiotene: 2-Macrophage colony stiumulating factor (GM- CSF) 3-Granulocyte colony stimulating factor: (G-CsF) 4-megakaryocyte growth factor 5|Page