Pharmacology Study Set 4
Quiz 46 :
Basic Principles of Anti-Infective Pharmacotherapy
To treat severe infectious disease, antibiotics are given through the intravenous route (IV) of administration. In this route the drug is administered into the peripheral vein, which can directly enter into the systemic circulation. The IV route of administration provides 100% drug absorption and allow the drug to act immediately.
Drug resistance is, the development of alternative mechanism of survival against the drug effect. So that, the drug cannot produce the pharmacological response. For example, beta lactamase is an enzyme that can breakdown the beta lactam ring of penicillins and cephalosporins. Certain bacterial species develop resistance against beta lactam antibiotics by synthesizing the beta lactamase enzyme. Tolerance is the decreased response of the body towards the drug with repeated administration. Means, the patient needs more quantity of drug to produce the same therapeutic response as before. For example, the down regulation of 2 receptors occur with repeated administration of salbutamol ( 2 agonist), which makes the patient to take more dose to get the relief from an asthmatic attack.
Antibiotics, when taken in higher doses, can cause more side effects as they can kill the other friendly microbes in the body. Instead, if we give two antibiotics that produce synergistic effect through different mechanisms against the target microbe, we can achieve a better death rate of the pathogen with less side effects. This therapeutic approach is used in the treatment of certain highly resistant strains such as tuberculosis, HIV, etc.