The Problem Of Antibiotic Resistance Is Becoming A Problem

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Scenario John Wesley is a 56 year old man who apart from taking warfarin for his chronic atrial fibrillation is not on any other medication. His International Normalised Ratio (INR) is monitored regularly so that it is around 2.5 (range 2.06-2.8). John goes to his GP with a lower urinary tract infection and is prescribed a 7 day course of cefixime, a 3rd generation cephalosporin. His GP tells John that he will need to come in the following week for a blood test for his INR. John starts the antibiotic and after 3 days is feeling a lot better, he continues with the antibiotics as he has heard that stopping antibiotics early is part of the reason for antibiotic resistance is becoming a problem. On the 5th day of his antibiotic treatment…show more content…
In this case, the patient was taking medication for his chronic atrial fibrillation when he developed a lower urinary tract infection. For this he was prescribed cefixime, a 3rd generation cephalosporin antibiotic. As a result, the 2 drugs interacted with each other whereby cefixime enhanced the effect of warfarin as illustrated by the elevated INR of 5.6. Most emphasis is placed upon the main principles of pharmacodynamics and pharmacokinetics; we also briefly discussed antibiotic resistance and how bacteria develop characteristics enable them to evade antibiotics. 1. Define Unclear terms • Warfarin: Warfarin inhibits the synthesis of vitamin K dependent clotting factors II, VII, IX and X and thus acts as an effective oral anticoagulant. It is given in a racemic mixture of the R and S stereoisomers and whilst both isomers act as vitamin K antagonists, S-Warfarin is 4 times more potent than R-Warfarin.[1] Warfarin is most commonly used in the treatment of deep vein thrombosis and pulmonary embolism. Its effectiveness is clear as it has been estimated that 1% of the population and 8% of those over 80 years use Warfarin.[2] • Chronic atrial fibrillation: A common type of arrhythmia [deviation from normal rhythm of the heart]. The atria are excited by random waves of depolarisation and the ventricular response is also irregular. Since only 1/3 atrial beats passes to the ventricles[3], blood is not ejected properly and there is an increased risk of clot formation.
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