I agree with MAKK, with respect to the broad accusation that it is only cabin crew who partake in drugs.
From Merriam-Webster online dictionary;
Main Entry: 1drug
Pronunciation: 'dr&g
Function: noun
Etymology: Middle English drogge
Date: 14th century
1 a obsolete : a substance used in dyeing or chemical operations b : a substance used as a medication or in the preparation of medication c according to the Food, Drug, and Cosmetic Act (1) : a substance recognized in an official pharmacopoeia or formulary (2) : a substance intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease (3) : a substance other than food intended to affect the structure or function of the body (4) : a substance intended for use as a component of a medicine but not a device or a component, part, or accessory of a device
2 : a commodity that is not salable or for which there is no demand -- used in the phrase drug on the market
3 : something and often an illegal substance that causes addiction, habituation, or a marked change in consciousness
More than a few pilots over the years have flown within the mandatory 8 hours and it is not unheard of to hear pilots bragging about how p!ssied they got last night!