Andrew Devenney, 21, faces jail after he pleaded guilty to being in possession of the items.
A hearing at Dumbarton Sheriff Court last week was told that police had seen Devenney unsteady on his feet while they were out on uniform mobile patrol at around 8.30pm on January 15.
They turned their vehicle around in Park Road, Dalmuir to check on Devenney’s welfare and they could tell he was intoxicated.
They also detected the smell of cannabis.
Devenney, the court was told, kept his hands in his pockets, so police detained him for a search, asking him if he had anything sharp.