Drugs in Haematological Disorders Tute PDF

## Drugs used in Hematological Disorders ### Case Study 1: 30-year-old man with IDA * **Patient:** 30-year-old man diagnosed with IDA with a Hb level of a gldh. * **Treatment:** Prescribed FeSO4 200mg tds, an antacid 20mg to be taken as required, and omeprazole 20mg mane for gastritis. * **Duratio...

## Drugs used in Hematological Disorders ### Case Study 1: 30-year-old man with IDA * **Patient:** 30-year-old man diagnosed with IDA with a Hb level of a gldh. * **Treatment:** Prescribed FeSO4 200mg tds, an antacid 20mg to be taken as required, and omeprazole 20mg mane for gastritis. * **Duration of treatment:** 6 weeks * **Outcome:** Lack of response to iron therapy noted. **1. Explain the possible pharmacological reasons for the lack of response to pron therapy in this patient.** * The patient has been on FeSO4 200mg tds. The daily recommendation of elemental iron for the patients with iron deficiency anemia is 100mg - 200mg daily. Since FeSO4 200mg contains approximately 65mg elemental iron, the dose given for a day is adequate. * **The causes for poor response to oral iron therapy can be elaborated as follows:** * **Poor absorption:** * The patient has taken drugs which impair oral iron absorption like omeprazole and proton pump inhibitors significantly interact with orally given iron tablets. * Antacids and proton pump inhibitors reduce gastric acidity. * Gastric acidity is a contributory factor for iron absorption. * Antacid preparations contain divalent metal ions, which compete with oral iron to get absorbed through the transporter. * If the patient has taken FePO4 tablets without proper spacing (like 2 hrs before or 4 hours after those drugs), it may lead to oral iron malabsorption. * Forgetfulness due to side effects. * Poor compliance to therapy may also be a reason for this poor response. * **High dose:** * The preparation with a relatively higher content of elemental iron, has a likelihood of developing side effects. * Side effects like nausea, epigastric discomfort, abdominal cramps, constipation and diarrhea, can make the patient miss 1 or more doses of a drug which is given three times per day. * With development of side effects like epigastric discomfort which mimic gastritis, the patient may take antacids more frequently, which in turn further impair oral iron absorption. * **Underlying complication:** * The patient has gastritis. There can be underlying complications like perforated peptic ulcers, which lead to iron deficiency anemia. * In case of a gastro-intestinal bleeding, response to oral iron therapy is poor, due to ongoing iron loss through GIT, when it is given orally. **2. Briefly describe the measures you would take to address the factors you explained in 2.1.** * **Ask the patient for the compliance towards FeSO4.** * If there is an inability of oral iron due to troublesome side effects, reducing the dose or changing to a different preparation with less content of elemental iron like Fe gluconate. * Ask the patient to take iron tablets with meals. * **Provide proper health education on taking oral iron tablets and drugs that impair iron absorption like antacids & PPI.** * Ask the patient to space out those things with oral iron. (2 hours or 4 hours after the meal). * **Educate the patient on the foods with impair or improve iron absorption:** * **Reduce iron absorption:** Meals, eggs, coffee, tea, Oxalates (spinach, tea), Phytates (tea, cocoa, fiber, cereals), Calcium (milk, yogurt, Ash). * **Increase iron absorption:** Vitamin C, orange juice. * **Despite all those patient oddities, if response to oral iron therapy is still low, investigate for any underlying cause like perforated, bleeding peptic/gastric ulcers by doing endoscopy, and other relevant investigations can be done, if there is a suspicion of any other underlying disease or GI tract.** ### Case Study 2: 60-year-old man with CKD * **Patient:** 60-year-old man with CKD complaining of SOB on exertion, lethargy, palpitations. Hb is 2.5g/dL. **1. Discuss the place of erythropoietin in this patient.** * **CKD** is a progressive disease in which kidneys gradually lose their functional capacity. * **Erythropoietin** is a glycoprotein hormone produced by the renal cortex which stimulates erythropoiesis in bone marrow. One of the causes of anemia in CKD is due to insufficient erythropoiesis by kidneys due to reduced production of erythropoietin. * **This patient's Hb is below 3g/dL, which is suggestive of severe anemia.** * **The patient shows symptoms of anemia such as SOB on exertion, lethargy, and palpitations.** * **Since the damaged kidneys cannot produce sufficient erythropoietin, it can be given as a drug for CKD patients with symptomatic anemia.** * **So, this condition is an indication for erythropoietin.** **2. Outline the important precautions related to erythropoietin.** * Most of the patients on erythropoietin should be given oral or parenteral iron supplement to enhance the efficacy of erythropoiesis. * Some patients may need folate supplementation as well, to improve erythropoiesis. * **Look for any contraindications for erythropoietin before initiating treatment.** * Eg: Uncontrolled hypertension. Hypertension should be controlled before initiating treatment with erythropoietin. * **Ask the pt. for their past medical hx, and be cautious if the patient has a history of epilepsy, poorly controlled hypertension, DHD, or malignant disease.** * **Educate the patient on possible adverse effects, and ask him to seek prompt medical advice if there’s any evidence of those side effects after initiating erythropoietin treatment.** * Side effects include: * **Hypertension:** Close dependent including hypertensive crisis. * **Thrombotic complications:** Serious cardiovascular events, thromboembolic events, stroke, short thrombosis, etc. * **Poorly cutaneous adverse reactions including**: * Steven-Johnson syndrome (SJS), * Toxic epidermal necrolysis (TEN). * In some cases, those skin reactions are fatal. Therefore, the patients and their carers should be advised of signs and symptoms of severe skin reactions. * **Over-correction of Hb concentration in patients with CKD can increase the risk of serious cardiovascular events that can even cause death.** * **The patient should be frequently followed up for blood Hb levels which should not exceed 10-12 g/dL.** * **If Hb level is >11 g/dL, treatment should be stopped.** * **The aim of giving erythropoietin is only relieving symptoms of anemia, and not over-correction of Hb levels.** * At the same time, correcting other factors contributing to anemia in CKD is also important, rather than only administering erythropoietin. * Most of the patients require oral / parenteral (if on hemodialysis) iron supplements. * Some patients may require folate supplements. **3. List the indications for folic acid, stating the differences in dosing.** * **Folic acid deficient megaloblastic anemia:** 5mg orally daily for 4 months. (During prolonged megaloblastic anemia, folic acid should be taken along with Vitamin B12) * **During pregnancy, to prevent neural tube defects (NTD):** * All women are recommended a daily dose of 400-500 mcg before conception and in the first 12/52 of pregnancy. * 1mg tablet given daily due to availability. * Some preparations have folic acid + FeSO4. * **For women with a hx of NTD in a previous child:** a higher dose of folic acid is given, which is 5mg daily before conception continuing for 12/52 of conception. * **Prevention of methotrexate induced side effects in rheumatic diseases:** 5mg once weekly, due to be taken on a different day to methotrexate dose. (Methotrexate on Sunday, folic acid on Wednesday, following methotrexate dose). * **Prophylaxis for:** * Chronic hemolytic anemia. * Malabsorption. * Folate deficiency in renal dialysis. * Give orally a weekly or a daily dose depending on requirement.