At what point should a compound no longer be considered advisable for human use? What circumstances might affect this decision? Are there any circumstances in which a compound with potentially dangerous side effects should be administered anyway? If so, what might those circumstances be and who should be allowed to make that decision?

Barbiturates and barbiturate-like compounds were developed more than a century ago. Their action does not affect only those specific neurons involved in the process of inducing anxiety, insomnia, or consciousness, however. They affect every neuron that accepts GABAa as a neurotransmitter, reducing the neurons’ firing rate. Thus, the action of the barbiturates could be compared to the action of the fire blankets found in many laboratories; when thrown over a fire, they not only smother the flames, but also cover such a wide area that nearby objects are damaged as well.

Using this analogy, the fire itself covers only a small area, possibly less than two or three-square feet. When deployed, the fire blanket might cover twenty or thirty square feet, damaging equipment and experiments uninvolved in the fire at the time. The barbiturates’ action is seen not only on those neurons involved in the process of consciousness, but also those involved in a range of other useful activities, such as respiration. Their therapeutic window is very small, and when combined with alcohol (itself a central nervous system depressant) fatal overdoses can occur easily.