The Relationship of Pathophysiology and Pharmacology - Essay Example

Patho-Physiology and Pharmacology Scenario Ans Heart failure is a disease characterized by the inability of the heart to pump enough blood in the vascular system leading to hypoperfusion of different organs and systems in the body. Whenever a person suffers from heart failure, there is a decrease in the cardiac output. This decreased cardiac output leads to the accumulation of blood in the ventricles. Accumulation of blood in the ventricles leads to the accumulation of blood in the atria and the venous channels. Depending on the type of heart failure i.e. right or left, the blood will be accumulated in different organs and systems of the body (Goljan, 2010). Whenever there is left sided heart failure the blood accumulates in the lungs first and then the pulmonary arteries and then right sided heart failure occurs. But, in this case, the patient suffers from right sided heart failure which means there would first be accumulation of blood in the right ventricle and then the right atrium. This accumulation of blood in the right atrium would lead a decreased venous return. This decreased venous return would then cause the accumulation of blood in the peripheral veins. The veins most affected are the veins in the leg. The gravitational force leads to the accumulation of blood in these veins. Accumulation of blood increases the hydrostatic pressure in these veins leading to the disturbance of starling’s forces and movement of fluid outside these vessels causing pretibial and ankle edema. The cause behind irregular pulse can be simply identified by the atrial fibrillation. In atrial fibrillation, there is abnormal transmission of pulses from the transmitters from the atria into the purkinjee fibres of the ventricles. This abnormal transmission of impulses leads to abnormal patterns of contractions of ventricular muscles causing an irregular contraction and relaxation pattern and an abnormal cardiac cycle (Cotran, 1999). This abnoarmal cardiac cycle due to irregular transmission of impulses is what causes an irregular pulse. Ans. 2 Ramipril is a carboxylic derivative and belongs to a class of drugs known as ACE inhibitors. Ace inhibitors are those drugs that inhibit an enzyme Angiotensin converting enzyme. The major function of this enzyme is to convert angiotensin 1 to angiotensin 2. The converted angiotensin 2 helps increase the blood pressure by several mechanisms. Some of these are: secretion of aldosterone which acts on the DCT in the kidney to increase the absorption of sodium and water, also the secretion of ADH which by its name the Anti Diuretic Hormone, decreases the excretion of water from the kidney leads to an increase in the circulating volume and increases blood pressure. By inhibiting the action of ACE, ramipril inhibits formation of angiotensin 2 thus its subsequent actions are also inhibited and blood pressure is maintained (Lippincott, 2005). Ramiprial has an active form known as ramiprilat. Administered orally, the absorption of ramipril is usually 50-6-% and when administered with food the absorption of this drug decreases but not significanty. The drug reaches its peak plasma concentration in about half an hour after administration and the rate of decrease in plasma concentration is as quick. The drug acts by binding of its C domain with the enzyme at its active site thus inhibiting the binding of angiotensin 1 and its conversion to angiotensin 2. The drug has a half life of 20 hours and subsequent doses usually lead to a steady plasma concentration rather than a single dose whose effect is not that steady. Almost 90% percent of the excretion of this drug is through feces whereas the remaining 10% is excreted through urine. The activity i.e. inhibition of enzyme activity depends on the doses administered (Trevor, 2008). Ans. 3 A patient such as Jack can be at a huge risk of developing a thrombosis in any of the vital vessels. Since he is suffering already from heart failure, the slow progression of blood i.e. stasis can lead to thrombus formation in the vessels and may lead to the blockade of one of the vital vessels such as coronary or cerebral vessels. The prescription of warfarin as a prophylactic medicine would help a smooth flow of blood through these channels. Warfarin acts by inhibiting the formation of prothrombin which is the initial step in the formation of a thrombus and blocking of blood vessels. With no formation of prothrombin, the risk of developing an ischemic disease due to thrombus or even ischemic heart failure such as MI would be decreased (Trevor, 2008). Scenario 2 Ans. 1 COPD or Chronic Obstructive Pulmonary Disease is characterized by the obstruction of major airways starting from trachea to small airways like bronchioles. The disease further consists of other diseases such as Chronic Bronchitis, bronchiectasis and asthma. All of these diseases have their own symptoms and pathophysiology. Asthma is characterized by the abnormal constriction of airways due to the presence of an allergen in the respiratory tract. The allergen triggers the formation and release of antibodies and histamine from mast cells which then causes the constriction of airways leading to shortness of breath and dyspnea. Other diseases such as chronic bronchitis is characterized by the over production of sputum by the goblet cells of the trachea and bronchioles (Hall, 2012). The excessive production of sputum leads to its entrapment in the respiratory pathway due to the inability of cilia to push it upwards to be expectorated. The abnormality in cilia could be due to pathologies such as an abnormal dynin arm or ciliary dyskinesia. The accumulated sputum leads to the obstruction of airways and also serves as an effective medium for infectious agents to grow. In the case of this patient, the entrapped sputum served as an important medium for the infectious agent to grow and cause infection. The inflammatory response initiated and there was more production of mucus but the inability of cilia to expectorate it led to its further accumulation and worsened the symptoms of this patient. Pyrexia is due to the presence of a pyogenic organism which caused an inflammatory reaction and the formation of purulent sputum which is being expectorated as well as blocking the respiratory tract causing dyspnea. The exacerbation of all these symptoms in the presence of an infection shows an inflammatory response to the infectious agent and the presence of immune system to fight against the agent (Cotran, 1999). Ans. 2 Beclometasone is a corticosteroid used mainly in the treatment of inflammatory disorders. The ability of corticosteroids to relieve inflammation is one of their most important uses in the world. This drug a glucocorticoid is supposed to play an important role in the inhibition of inflammatory pathways when they are not required or causing more than required damage to the host. The drug crosses cytoplasmic membranes and binds to specific receptors. These receptors are activated or rendered inactive and lead to many actions such as the inhibition chemokines that would lead to the inhibition of chemotaxis of inflammatory cells such as leukocytes. Also, the humoral immunity is inhibited as well as other inflammatory mediators and cells are either inhibited or deactivated (Trevor, 2008). This in turn leads to a decreased inflammatory response at the site of infection. The action of beclomatasone in this patient is to decrease the inflammation which would in turn lead to a decrease in the production of mucus which is already trapped and obstructing the respiratory tract. A decrease in the inflammatory response leading to decrease in mucus production would eventually lead to the opening of the respiratory tract and the symptom of dyspnea will be alleviated. Also, the administration of this drug by inhalation would provide rapid action since the first pass metabolism would be bypassed as well as the drug would reach its site of action far quickly and easily than other routes of administration. With the alleviation of inflammation, the symptom of pyrexia would also be alleviated as well since it is just a sign of an ongoing inflammatory reaction in the body. Acting at the site of infection, beclomatasone would reduce inflammation hence the production of sputum, production of inflammatory mediators and bronchoconstriction would be alleviated. So we can say that Beclometasone would provide a sudden and brief symptomatic relief of the patient and give the doctor some time to the find out the actual cause behind the symptoms with the patient now relaxed (Lippincott, 2005). Ans. 3 The sputum of this patient has been sent to the laboratory for analysis because the patient is suffering from COPD a disease in which the sputum accumulates in the respiratory tract and harbors the infectious agents. With the analysis of his sputum in lab, the physician would be able to identify the causative agent behind this exacerbation of symptoms and plan out a formal and proper pharmacological regimen. Also, other expected causes for his disease could be ruled out. A sputum analysis for mycobacterium TB or other communicable organisms would provide the physician with a general knowledge of the prevalence of this disease and the patient could well be separated from the general ward to isolation to prevent the spread of the disease as well as his relatives should be screened if any such disease is found (Goljan, 2010). The presence of any sort of virus or bacteria and identification of their type would eventually lead to a final diagnosis and a pharmacological treatment aimed at removing the causative organism can be planned. Scenario 3 Ans. 1 Type 1 Diabetes Mellitus is a genetically transferred disease usually present in families and is considered to be the most common of all hereditary diseases. The symptoms appearing the patient immediately prior to the diagnosis of this diseases are due to several factors. First of all the main reason behind all these symptoms is high blood glucose levels due to absent insulin. The absence of insulin renders the glucose unable to enter the cells and to be used by them to produce energy. This increased blood glucose is carried by the blood to the kidneys where it is filtered. The kidneys have a maximum threshold of 180 and when the glucose levels cross this threshold, it starts appearing in the urine hence the symptom of glycosuria. Also, this glucose makes the urine hyperosmotic and more water is filtered through the nephrons and tubules making excessive urine formation. This excessive urine causes polyuria (Mccance, 2002). Also, when cells are not able to use glucose as a source of energy, they divert towards fats and proteins as a source of energy and body’s store of fat and proteins is diminished appearing in the form of weight loss. The usage of fats for energy produces ketone bodies and hence the breath is ketotic. Polyphagia and fatigue are the symptoms when the body is in the phase of growth but not enough nourishment is being provided to it. The first of three primary sources of energy for the body are carbohydrates and body preserves fats and proteins for emergency situations as well as build the body mass. In the absence of carbohydrates, the body is not provided with enough nourishment, the nutrients do not reach the organs, bones and joints leading to the symptoms of fatigue as well as polyphagia due to joint abnormalities. All these symptoms appear just before the diagnosis because DM is diagnosed when the sugar levels rise too high to be obvious and these symptoms appear due to continuously high sugar levels (Mccance, 2002). Ans. 2 For Chelsea to be healthy and live a long life with no other co morbid, she would have to keep her blood sugar levels in the normal range. With the levels out of control for a long time the long term consequences could very well be fatal. The increased blood sugar levels have a direct effect on the kidneys. They increase the workload on nephrons and glomerular capillaries and can lead to arteriosclerosis which can very well lead to renal failure. Also, the factor of delayed wound healing in the presence of high blood sugar levels can cause diabetic foot and may lead to limb amputation (Cotran, 1999). Diabetic nephropathy, diabetic retinopathy, diabetic neuropathy and many other diseases can be caused by diabetes. Ans. 3 Type 2 Diabetes Mellitus, or non-insulin dependent diabetes mellitus is a disease of old age and obesity. Oral hypoglycemic drugs are used in this disease for the maintenance of blood glucose levels. These drugs include sulphonylureas and biguanides. Sulphonylureas are further classified as first and second generation. The drug prescribed to the patient here is glipzide which is a second generation sulphonylurea (Trevor, 2008). Glipzide is known to be a rapidly acting oral hypoglycemic with a short duration of action. This drug acts mainly by blocking the potassium channels of the beta cells. The blocking of potassium channels allows for the cells to release insulin for longer duration of time. This increased level of insulin would increase the cellular uptake of glucose making it available to produce ATP and decrease plasma glucose levels. Metformin on the other hand is the drug of choice in type 2 DM (Rang, 2003). this drug decreases plasma glucose levels by directing its action on the glucose production by the liver. The drug decreases the glucose production by hepatocytes and thus leads to a decreased plasma glucose concentration. References HALL, J. E. (2012). Guyton and Hall Textbook of Medical Physiology Enhanced E-book. London, Elsevier Health Sciences. http://public.eblib.com/EBLPublic/PublicView.do?ptiID=1429954. LIPPINCOTT WILLIAMS & WILKINS. (2005). Clinical pharmacology made incredibly easy. Philadelphia, Lippincott Williams & Wilkins. TREVOR, A. J., KATZUNG, B. G., MASTERS, S. B., & KATZUNG, B. G. (2008).Katzung & Trevors review of pharmacology. New York, McGraw-Hill Medical. COTRAN, R. S., KUMAR, V., COLLINS, T., & ROBBINS, S. L. (1999). Robbins pathologic basis of disease. Philadelphia, Saunders. GOLJAN, E. F., & GOLJAN, E. F. (2010). Pathology. Philadelphia, PA, Mosby/Elsevier. MCCANCE, K. L., & HUETHER, S. E. (2002). Pathophysiology: the biologic basis for disease in adults & children. St. Louis, Mosby. RANG, H. P. (2003). Pharmacology. Edinburgh, Churchill Livingstone. Read More