Drugs, Lec 7: 01/31/2014
Why do we choose ED50?
Steepest part of the curve at ED50, gives you the most reliable and most powerful correlation between
changing the dose and changing the effect. One numerical value to describe potency. Don’t want to take it
from the top or the bottom of the S, the effect changes very little with the change in dosage. Misinterpreting
the connection between dose and effect.
MED: minimum effective dose. ED100, effective dose in 100 percent of the rats and humans. We want the
minimum to be as economically efficient as possible. Least likely to produce side effects too. MED is what
dose you give in a medication.
Pretreatment with an antagonist can cause the drug to be less efficient. Competing at the same receptor
tells you how the drug works. You can put the agonist and the antagonist together to separate the drug
producing therapeutic effects and the one producing side effects. Doesn’t always happen, don’t always
have separate receptors for both drugs. Can’t always stimulate one and block the other.
Ex. exam question, graph with no x or yaxis labeling.
Pharmacokinetics: xaxis is time, yaxis is blood concentration of the drug.
BAL: blood alcohol level.
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