Two 28-year-old men and a 26-year-old colleague came up with the “bright idea” of making homemade pastries filled with the illegal drug in an apartment in the city of Saint Gallen, cantonal police said on Sunday.
They were not aware of any recipe for such pastries and so they put all the available cannabis they had into the dough, police said in a statement.
With the baked “brownies and space cakes” they visited on Saturday night a 30-year-old friend in Zuzwil, a municipality 26 kilometres northwest of the city of Saint Gallen.
While there they consumed the “hash pastries” which “sparked violent side effects”, police said.
The group managed to make a phone call to emergency services and the four were taken to hospital for treatment.
Two ambulances, doctors and several police patrols responded to the call for help, the force said.