While there are many recognized saints who are listed with multiple and diverse patronages, like St. Monica and St. Joseph, there are some who are known principally for one or two patronages, such as St. Maximilian Mary Kolbe among addicts and prisoners. (While not a drug addict himself, St. Kolbe was killed by Nazis with an injection of carbolic acid in the extermination camp of Auschwitz in 1941.)
Although (yet to be canonized) Venerable Matt Talbot is widely regarded solely as patron for alcoholics, he certainly qualifies as being considered a patron for labourers (laborers/workers), as those in the USA celebrate Labor Day today. Matt did manual labor his entire life, beginning at the age of 12.