Fencamfamine (Glucoenergan, Reactivan) is a stimulant which was developed in the 1960s as an appetite suppressant, but was later withdrawn for this application due to problems with dependence and abuse. It is around half the potency of dexamphetamine, and is prescribed at a dose of 10-60mg, although abusers of the drug tend to rapidly develop tolerance and escalate their dose. Reactivan is still rarely used for treating depressive day-time fatigue, lack of concentration and lethargy, particularly in individuals who have chronic medical conditions, as its favourable safety profile makes it the most suitable drug in some cases. [Wikipedia]