Not technically a drug, but rather a synthetic genetic cocktail designed to be taken by pregnant mothers to reduce pre-natal problems and grant immunity to several childhood diseases, The Fix is a small grey pill, shaped like two cones joined at their wider ends, and resembling more than anything else a weight from a fishing line (without the hole for the line).
Although it is not actually compulsory for pregnant mothers to take, a few decades from now, it might as well be. There are exemptions, but they mostly involve religious grounds. And in the highly regulated future from which it originates, refusal to take the damned thing without a good reason (and it should be noted that the vast majority of so-called good reasons are actually irretrievable irrantionality that the government apparently hopes to breed out of the population over the next few generations) will make the pregnant woman in question the target of all manner of government intervention.
All for the good of the unborn child, of course. Because someone has to think about the children.