Pictured above is a prescription, written by a doctor in 1925 for one pint of whiskey to be taken "as required." As you can see, the pad was issued by the United States Treasury Department, which had responsibility for Prohibition enforcement. The pads were sequentially numbered and printed on bank note paper to prevent counterfeiting.
In the political give and take leading up to the 18th (Prohibition) Amendment, an exception was carved out for medicinal use. A century ago, many physicians regarded alcohol as a beneficial tonic. Old Forrester Bourbon was named for Dr. William Forrester, a prominent Louisville physician whose endorsement launched the brand and with it the Brown-Forman Company. (The extra 'r' was dropped after his death.)
As the Prohibition movement gained ground, medical opinion became divided. Many Prohibitionist doctors condemned alcohol absolutely, calling it poison. It largely broke down along religious lines, with Protestant physicians favoring Prohibition and Catholic, Jewish, and unaffiliated doctors generally regarding moderate alcohol consumption as normal and healthy.
Although the Prohibitionists succeeded in banning most alcohol use, they accepted the medical exception, as well as one for bakers to get rum for rum cakes. Rules were established. Doctors could write prescriptions for no more than one pint per patient per month. Prescription pads were issued. Whiskey for medicinal use would be withdrawn from existing aging stocks by pharmaceutical companies who would bottle it and sell it to drug stores, who would sell it to patients just like any other prescription drug. It would all, of course, be closely supervised by the federal government.
A fledgling Chicago drug store chain called Walgreens did very well during Prohibition.
It didn't take long for a slick Chicago criminal defense attorney to see a hole big enough to drive a liquor-laden truck through. A pharmacist before he took up law, George Remus acquired a pair of pharmaceutical companies, bribed government officials to obtain whiskey withdrawal permits, bought shuttered distilleries and their inventories for pennies on the dollar, and began to remove whiskey barrels by the hundreds, all intended (so the paperwork claimed) for medicinal whiskey channels, and all apparently legal.
Remus relocated to Cincinnati to be close to his distillery properties in Indiana and Kentucky. He got very rich before he got caught. His story is quite entertaining.
The prohibition of products or services that people want will always be problematic in a free society. If consumer demand can't be satisfied legally, it will be done on the down low, but it will be satisfied. The whiskey secondary market is a current example. Right now, nobody is enforcing the laws but they remain in effect. Even without the fear of legal consequences, there are problems. Among them, illicit markets inevitably attract the criminally inclined.
We've seen it all before.