Drugs for Anemia - Lecture Notes PDF

Drugs for anemia Year: 2 Semester: 1 Module: Blood Instructor information Name: Dina Abdel Karim A Ali Department: Clinical Pharmacology Office hours: Monday 11-1 pm  INTRODUCTION Case Scenario: A 15- years old- female pat...

Drugs for anemia Year: 2 Semester: 1 Module: Blood Instructor information Name: Dina Abdel Karim A Ali Department: Clinical Pharmacology Office hours: Monday 11-1 pm  INTRODUCTION Case Scenario: A 15- years old- female patient presented to the family medicine outpatient clinic complaining of easy fatigue and dyspnea on effort. Her laboratory results showed: Hb= 10, microcytic hypochromic RBCs with low level of serum ferritin. The case is diagnosed as Iron deficiency anemia. Objectives: By the end of this lecture, students will be able to: 1. Classify different types of anemias 2. Give short account on iron absorption 3. Identify management of iron deficiency anemia and common adverse effects of iron therapy 4. Give short account on treatment of megaloblastic anemia 5. List drugs inducing hemolytic anemia 6. List drugs inducing aplastic anemia. Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Classify different types of anemias Anemia is a hematological condition in which there is reduction Hb concentration in the blood below normal, may be accompanied by of reduction of RBCs count. Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Classify different types of anemias Blood loss Deficiency Classificati on of Reduced anemia Aplastic production Anemia of Hemolytic chronic disease Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Classify different types of anemias Normocytic Microcytic Macrocytic normochromic hypochromic anemia anemia anemia Vitamin B12 deficiency Acute blood loss Iron deficiency Folic acid deficiency Hemolytic anemia anemia (low Aplastic anemia (BM ferritin) depression) Chronic CKD inflammation (normal level of Ferritin) Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Give short account on iron absorption Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Give short account on iron absorption Iron is absorbed mainly in the duodenum and proximal jejunum. Iron crosses the luminal membrane of the intestinal mucosal Cell active transport. Absorbed iron can be actively transported into the blood by a transporter known as ferroportin and oxidized to ferric iron (Fe3+). Excess iron is stored in intestinal epithelial cells as ferritin. Iron absorption increases in response to low iron stores or increased iron requirements. Iron is transported in plasma bound to transferrin. The transferrin-iron complex enters maturing erythroid cells by a specific receptor mechanism. Transferrin dissociates and returns back to the plasma. Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Give short account on iron absorption Storage of iron as ferritin occur in intestinal mucosal cells, in macrophages in the liver, spleen, and bone, and in parenchymal liver cells. Iron Elimination There is no mechanism for excretion of iron. Small amounts are lost in the feces by exfoliation of intestinal mucosal cells. Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Identify management of iron deficiency anemia and common adverse effects of iron therapy It occurs as a result of to deficiency of iron (microcytic) Causes of iron deficiency anemia: Increased iron requirements. Such as: infants, children during rapid growth periods; pregnant and lactating women; patients with chronic kidney disease Inadequate iron absorption (malabsorption) Chronic Blood loss (GI bleeding, heavy menstruation, hemodialysis) Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Identify management of iron deficiency anemia and common adverse effects of iron therapy Treatment: stop the cause if possible. Iron supplements Preparations available: oral: Ferrous sulfate, Ferrous gluconate, Ferrous fumarate. parentral preparations: iron dextran (test dose), ferric carboxymaltose and iron sucrose. General principles for oral iron supplements: Daily requirement in normal person: 10-15 mg (10-15% absorbed) to maintain normal level prophylaxis: 30-60 mg elemental iron/day ttt of iron deficiency: 200-400 mg elemental iron/day (25% absorbed) absorption of iron is decreased with 2nd dose. (preferred once daily, after meal, ferrous salts, away from Ca or Zinc) ttt is continued until HB level is normal and 2-3 months after that ? Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Identify management of iron deficiency anemia and common adverse effects of iron therapy parenteral iron therapy: - indicated in noncompliance to oral therapy, malabsorption syndrome and severe anemia e.g malignancy TDI (Total dose Infusion): (avoid noncompliance and allows delivery of the entire dose necessary to correct deficiency) Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Identify management of iron deficiency anemia and common adverse effects of iron therapy Side Effects: A. Acute Iron Toxicity Occurs in young children accidently ingesting iron tablets. necrotizing gastroenteritis with vomiting abdominal pain, bloody diarrhea followed by shock, lethargy, and dyspnea severe metabolic acidosis, coma, and death  Treatment of this toxicity: raw egg+milk (bind and precipitate iron) until a chelating agent is available Intravenous administration of Desferrioxamine, a potent iron-chelating compound, whole bowel irrigation (Na bicarbonate) and oral Desferrioxamine in water Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Identify management of iron deficiency anemia and common adverse effects of iron therapy B. Chronic Iron Toxicity: (chronic hemochromatosis) Occurs in hereditary diseases (iron overload) or Repeated blood transfusion Treatments: iron chelating agents (IV) deferrioxamine or the oral deferasirox or deferiprone. Side effects of iron supplements constipation dark stools (mask GI bleeding) stomach pain nausea vomiting. Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Give short account on treatment of megaloblastic anemia vitamin B12 (CyanoCobalamin) deficiency anemia: Sources of Vit B12 in diet are: meat, eggs, or dairy products. Causes of Vit B12 deficiency: lack of intrinsic factor or to loss or malfunction of the absorptive mechanism in the distal ileum. Pernicious anemia, partial or total gastrectomy, and conditions that affect the distal ileum, such as malabsorption syndromes, inflammatory bowel disease, or small bowel resection.  Strict vegans eating a diet free of meat and dairy products. Treatment: Vitamin B12 supplementation. Preparations: CyanoCobalamin and hydroxocobalamin given as Oral and parenteral preparations Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 Give short account on treatment of megaloblastic anemia Folic acid deficiency: causes: Nutritional deficiency, malabsoption, pregnancy, liver disease Drug induced: phenytoin, contraceptives, Methotrexate (DHFR inhibitor) Objective 1 Objective 2 Objective 3 Objective 4 Objective 5 List drugs inducing hemolytic anemia. Examples of drugs causing hemolytic anemia (Excessive RBCs destruction) : Cephalosporins (a class of antibiotics), most common cause Levodopa Levofloxacin Methyldopa Nitrofurantoin, quinolones Nonsteroidal anti-inflammatory drugs (NSAIDs) Penicillin and its derivatives Quinidine Objective 6 Objective 7 List the drugs causing aplastic anemia Aplastic anemia is pancytopenia (anemia, neutropenia, and thrombocytopenia) with a hypocellular bone marrow and no increased peripheral blood cell destruction. The cause of drug-induced aplastic anemia is damage to the hematopoietic stem cells before their differentiation. This damage effectively reduces the normal levels of circulating erythrocytes, neutrophils, and platelets It can be: 1- Hereditary (less common) or 2- Acquired (more common) caudsed by drugs, radiation, viruses, or chemical exposure. Objective 6 Objective 7 List the drugs causing aplastic anemia Cytotoxic chemotherapeutic drugs Mercaptopurine …. etc. Antibiotics: Chloramphenicol Sulphonamides Nonsteroidal anti-inflammatory drugs (NSAIDs): Indomethacin Antiepileptic drugs: Felbamate Anti-thyroid: Carbimazole Propylthiouracil Antipsychotics: Chlorpromazine Clozapine Objective 6 Objective 7 Discuss management of hemolytic anemia Supportive treatment Attention to fluid balance Oxygen therapy Blood Transfusion when essential Treatment of iron overload (that can be caused by frequent transfusions in chronic conditions) Administration of desferrioxamine which chelates iron Folate therapy to support the increased RBCs turn over Withdrawal of the causative drug Objective 6 Objective 7 Discuss management of aplastic anemia Withdrawal of the causative drug Blood Transfusion to replace lacking component of the blood Protection from and treatment of any infection (Antibiotics) Corticosteroids: May increase hemoglobin, platelets & WBCs ATG (antithymocyte globulin): (IgG) against human T lymphocytes Immunosuppressive therapy in immune-mediated hemolytic anemias Bone marrow transplantation in severe cases  Quiz Time 1- An 18- year old female patient who is malnourished. She was complaining of hair loss. After clinical examination her doctor prescribed an oral iron tablet once/day. One of the common side effects of oral iron therapy is: A. Diarrhea B. Alopecia C. Black stool D. Oral ulcers  Quiz Time 2- A 3 year old male patient presented to the emergency room after accidental ingestion of a pack o iron tablets that was belonged to his mother. He was suffering from severe abdominal pain and bloody diarrhea known as acute iron toxicity. What is the suitable treatment for his condition? A. Give Desferrioxamine B. Give Folic acid C. Give paracetamol D. Give iron tablets  Quiz Time 3- What is the type of vitamin B12 deficiency anemia? A. Microcytic anemia B. Macrocytic anemia C. Normocytic anemia  Quiz Time 4- What does drug induced hemolytic anemia means? A. Excessive RBCs destruction B. Bone marrow suppression C. Reduced number of platelets D. Excessive number of RBCs  Quiz Time 5- A 15- years old- female patient presented to the family medicine outpatient clinic complaining of easy fatigue and dyspnea on effort. Her laboratory results showed: Hb= 10, microcytic hypochromic RBCs with low level of serum ferritin. The case is diagnosed as Iron deficiency anemia. The doctor prescribed: A. Iron oral tablet B. Desferrioxamine IV C. Folic acid tablet D. Thiamine tablet  Take Home Message 1.Classify different types of anemias 2. Give short account on iron absorption 3. Identify management of iron deficiency anemia and common adverse effects of iron therapy 4. Give short account on treatment of megaloblastic anemia 5. List drugs inducing hemolytic anemia 6. List drugs inducing aplastic anemia. 7. Discuss management of aplastic anemia and hemolytic anemia  References Lippincott Illustrated Reviews Pharmacology Thank you  General Guidelines for PowerPoint Presentations Make your objectives SMART (Specific, Measurable, Achievable, Relevant, and Time-bound). Select sans serif font types for clarity and readability. Don’t use font size less than 34. Don’t overcrowd your slide with unnecessary words or figures. Use clear and high-quality pictures, diagrams, illustrations, and infographics. Label important structures in your pictures. Use animation to highlight important structures, ideas, or information Use the following links to download the PowerPoint guide and the checklist: PowerPoint guide PowerPoint Checklist