Metafilter user maxwelton writes:

If you're thinking about being bitten by a coral snake in the United States, you may want to do so before the end of the month. October 31, 2012 is the extended-extended-extended-expiration date for batch 4030026 of the only FDA-approved antivenin for coral snake bites. (Antivenin shortages are not uncommon, surprisingly enough.) FDA-approved coral snake antivenin has not been available new since 2003, as Wyeth Pharmaceuticals ceased its manufacture, citing a lack of profit. Antivenin from non-FDA-approved sources exists, but the $3-5M estimated cost of FDA approval (borne by the manufacturer) and the few doses used per year mean it's a non-starter for the manufacturer of Coralmyn, for example.

There are two lessons to be learnt here, and likely people will already know which one they're planning on emphasizing. One is that the FDA sorely needs to come up with a better way to run its approval process when it comes to niche medicines. It's one thing demanding an expensive battery of tests if the manufacturing company thinks it will be selling billions of doses a year (and in fact, recent examples have hinted that perhaps those tests ought to be even more rigorous), but if it costs millions to bring a drug to market, many valuable treatments will be lost to the cost of bureaucracy.

The other side of the coin is that the profit motive is frequently toxic when it comes to the pharmaceutical industry. This particular antivenin could be made by any manufacturer, since it is already FDA approved. Yet no manufacturers are interested in creating it, because they can't make enough profit on doing so. The market outside the US is curtailed - because Coralmyn, made by a Mexican pharma company, is a better product - and the market in the US is too small for anyone to care about.

Anyone, that is, other than the 100-or-so Americans bitten by Coral snakes every year. Without an antivenin, the treatment is far harsher - and more expensive to boot. Popular Mechanics' Glenn Derene writes:

Many hospitals will have no other option but to intubate coral snake bite victims on ventilators for weeks until the effects of the toxin wear off--potentially costing hundreds of thousands of dollars per bite. "It's probably going to end up costing us far more not to deal with this than to deal with it," [Eric] Lavonas [of the Rocky Mountain Poison and Drug Center] says, "both in human suffering, and in dollars and cents."