Features of dose response curve
Plotting of dose response curve
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Effect- Y axis and Dose – X axis – hyperbola
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Effect- Y axis and Log Dose – X axis – sigmoid curve
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By taking log dose – a linear relationship in 30 – 70 % range gives a possibility of prediction of response in this range
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Response is proportional to an exponential function of the dose
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Log dose response curves are used to
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Potency – amount of drug required to elicit a response
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Relative potency – more meaningful than absolute potency
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A 10 times more potent than B – rightward shift of DR curve if less potent
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Potency need not mean clinical superiority
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Efficacy – the maximal effect produced by a drug and refers to the peak obtained in the DR curve.
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Eg. Morphine produces very high analgesia that cannot be obtained with any dose of aspirin
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Morphine highly efficacious than aspirin
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Last modified: Wednesday, 25 April 2012, 7:13 AM