DUI Laws in the Philippines

Not so much about the Picanto, but about driving in general. While I am aware that driving under the influence (DUI) of alcohol is prohibited all throughout the world, I am still unsure of the laws governing DUI here in the Philippines. Is it a national law? Does it depend on the area or city? Is it a city or municipal ordinance? It's just one of those things that we probably take for granted, regarding laws but as responsible drivers, we should really do it at all. I would be interested on the take of the lawyers regarding this concern. Comments greatly appreciated!