ED50[edit]
The median effective dose is the dose that produces a quantal effect (all or nothing) in 50% of the population that takes it (median referring to the 50% population base).[6] It is also sometimes abbreviated as the ED50, meaning "effective dose for 50% of the population". 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. This depends on the need for the effect, and also the toxicity. The toxicity and even the lethality of a drug can be quantified by the TD50 and LD50 respectively. Ideally, the effective dose would be substantially less than either the toxic or lethal dose for a drug to be therapeutically relevant.
ED95[edit]
The ED95 is the dose required to achieve the desired effect in 95% of the population.
In anaesthesia, the term ED95 is also used when referring to the pharmacology of neuromuscular blocking drugs. 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. Put another way, it is the ED50 for 95% reduction in twitch height.[7] The single twitch response occurs when a nerve stimulator is used to stimulate the ulnar nerve, and the degree of twitch of the adductor pollicus muscle is measured. A more accurate nomenclature when used in this way would be "ED5095".