This concept was exemplified in 2007 when a California woman died of water intoxication in a contest sanctioned by a radio station.
[4] The line between efficacy and toxicity is dependent upon the particular patient, although the dose administered by a physician should fall into the predetermined therapeutic window of the drug.
[5] Similarly, the MTD is the highest possible but still tolerable dose level with respect to a pre-specified clinical limiting toxicity.
The ED50 is commonly used as a measure of the reasonable expectancy of a drug effect, but does not necessarily represent the dose that a clinician might use.
In this context, it is the dose which will cause 95% depression of the height of a single muscle twitch, in half of the population.