Holy shit a question I can actually answer! I just graduated with a BA in history and wrote an honors thesis on cocaine use in London in the 1880s. Cocaine was first extracted from coca leaves in 1865. It spent the next fifteen years as a curiosity among academics. It wasn't until 1884 when, Sigmund Freud (then a young graduate student looking for a research chemical) wrote Über Coca, that cocaine became the fascination of the pharmaceutical world.

It was hailed as a miracle drug. At long last we had a stimulant drug. At the time doctors believed that all mental illnesses fell into two categories: mania or depression. Thankfully there was a cure for mania and hysteria: opium. Opium, a depressant, would obviously cure a surplus of energy. Unfortunately there was no such stimulating drug to cure the lack of energy for depression. Once cocaine was discovered it was hoped that it would cure melancholia and the like. Doctors began feverishly researching this new wonder drug.

Doctors immediately began testing cocaine on themselves. Naturally an epidemic of cocaine addicted doctors immediately developed. During the 1880s, cocaine was a darling drug of the medical community. After it was discovered to be a local anesthetic, doctors thought its possibilities might be endless. Cocaine was heralded as the cure for the common cold, a toothache number, a source of extra pep to keep up with the fast-paced modern world.

During the period between 1884 and 1895 cocaine was as easy to buy and in as many products as vitamins today. Any respectable person could easily walk into any pharmacy and select from cocaine cigarettes, cocaine lozenges, cocaine, cocaine creams, cocaine hair products, and of course regular cocaine powder. Cocaine was hailed as the new drug for the new "brain worker" for the modern industrial city. Cocaine users and "habitués" were mostly upper middle class office workers. In France, Angelo Mariani created a new cocaine wine tincture named, "Vin Mariani." One fl oz of Vin Mariani contained 6 mg of cocaine at 14% AVB. It was good stuff. Mariani, a bold man, sent a case it his elixir to every noble, celebrity, and intellectual of his day. In return all Mariani asked for was a returned photograph of the recipient and their autograph endorsing the tincture. Mariani received endorsements from everyone. Vin Mariani was enjoyed by Queen Victoria, Ulysses S. Grant, Alexandre Dumas, and even Pope Leo XII who granted it the Vatican Gold Seal of Approval.

By 1885 it became apparent that cocaine may have had a darker side to it. Cocaine is a highly addictive drug because it releases pure pleasure into the brain. A sensational headline about a cocaine addicted doctor was featured almost monthly in the New York Times from 1885-1886. As society began to see the hideous effects of cocaine addiction it rapidly lost prestige. Indeed even the stereotype of the cocaine addict shifted to the lower classes. By 1895 legislation in Britain regulating cocaine to a prescription-only-drug passed. By the 1930s cocaine was made entirely illegal except as a local anesthetic.

Primary Sources: "A REMEDY FOR MANY ILLS." New York Times (1857-1922), Sep 02, 1885. Mariani, Angelo. Coca and Its Therapeutic Applications, 2nd ed. New York: J.N. Jarod, 1892. Secondary Sources: Andrews, George and Solomon, David, editors. The Coca Leaf and Cocaine Papers. New York and London: Harcourt Brace Jovanovich, 1975. Freud, Sigmund. Cocaine Papers, Edited by Robert Byck, New York and Scarborough, Ontario: Stonewall Publishing Company, 1974. Jay, Mike. Emperors of Dreams: Drugs in the Nineteenth Century. Sawtry, UK: Dedalus, 2000 Spillane, Joseph F. Cocaine: From Medical Marvel to Modern Menace in the United States, 1884-1920. Baltimore and London: The John Hopkins Universu=ity Press, 2000

Edit: Holy shit my first reddit gold! My life is finally complete! Thank you kind stranger!

Not your exact question, but I suspect that this answer from /u/the_alaskan from last year will be of interest.

Just as a follow up to this, if you are interested in this periods drug use, the late victorian to early edwardian era were know as the great binge as many drugs including cocaine, opiates (including opium, morphine and heroin) and absinthe were readily available. In fact it is from this period that the term heroin was coined, as it used to be a trademarked brand name! Just google it, theres plenty of information that im sure you'd find interesting.