Anyway my colleague is willing to do cocaine and will go through the come down afterwards because he argue’s that the pleasure outweighs the pain. [...] It could be argued in this scenario that he is being Epicurean?! Thoughts!
Recreational drug use is a natural desire, though unnecessary. If he has performed the appropriate συμμέτρησις (weighing advantages versus disadvantages) and has determined that the high is worth the crash, then it's worth it.
There are a few considerations to cocaine use. First, Epicurus generally recommends against intoxication:
"The wise man will never indulge in drunkenness, says Epicurus, in his Banquet." (Wise Man Saying 13)
Cocaine intoxication stresses the cardiovascular system. At the same time, it tends to provide users with more utility than do depressants (like alcohol.) Beyond a heightened state of alertness that can propel someone to accomplish more tasks, cocaine has been demonstrated to enhance creativity by reinforcing divergent thinking. Of course, long-term, habitual use of the chemical can lead to permanent health complications that should be considered, and withdrawal symptoms (feeling like bugs are crawling under your skin) may weigh the scale against usage.
Epicurus provides another parameter we should consider:
"[S]elf-sufficiency we believe to be a great good, not that we may live on little under all circumstances but that we may be content with little when we do not have plenty, being genuinely convinced that they enjoy luxury most who feel the least need of it" (Epistle To Menoikeus).
Unfortunately for users, cocaine is one of the more expensive drugs, and generally harder to acquire a quality product. Unlike alcohol, which is cheap and ubiquitous, a cocaine habit is much harder to maintain due to socioeconomic factors. The habit depends on availability, and the availability is further determined by affordability. While cocaine might stimulate him in a pleasurable way, there are healthier (and cheaper) ways to achieve a similar high. Additionally, withdrawal symptoms make it harder to focus and generally maintain a healthy equilibrium.
There are also legal consequences to consider:
"It is impossible for the man who secretly violates any article of the social compact to feel confident that he will remain undiscovered, even if he has already escaped ten thousand times; for until his death he is never sure he will not be detected." (Key Doctrine 35)
"The wise man will not object to go to the courts of law." (Wise Man Saying 19)
The federal statute on limitation for illegal drug use is 5 years, and, depending on your location, and the temperament of law enforcement in your area, using cocaine may make you a target, or an easy arrest. Furthermore, having a record that includes possession charges can complicate future legal struggles. Of course, this is not necessarily a problem if you are a member of the upper class, as law enforcement overwhelmingly targets poor communities.
"[Epicurus] asks himself in his Problems whether the Sage who knows that he will not be found out will do certain things that the laws forbid. He answers, 'an unqualified prediction is not free of difficulty' – which means, 'I shall do it but I do not wish to admit it.' (Plutarch, Against Colotes, 34, p. 1127D)
The law is not absolute and is not necessarily just, and it is up to each of us to determine what is best for ourselves. Overall, I think rare cocaine use is generally fine in healthy adults, of course, to each their own.
"Provided that you do not break the laws or good customs and do not distress any of your neighbors or do harm to your body or squander your pittance, you may indulge your inclination as you please." (Vatican Saying 51)