Mood changes, aggression and a lack of energy are signs to look out for.
Employers are being reminded to look out for the after-effects of drug use in employees.
Figures from the Health Research Board show Irish young adults have the second highest rate of cocaine use in Europe.
Owner of Salutem Advisory and Training in Tullamore, Breda Colgan is highlighting mood changes, aggression and lack of energy as the main consequences of a weekend of heavy drug use.
She says employers aren't aware of how to deal with the issue: