Gardaí received a report that a man threatened staff at a pharmacy on South Terrace and left with a quantity of tablets at 3pm.
A description of the man was circulated to all Gardaí in the city and a man who matched the description was stopped on Anglesea Terrace.
The man was searched and found to be in possession of tablets.
He was arrested and brought to the Bridewell Garda Station where he is currently being detained.
