Tennessee officials hope a new law requiring doctors to check a database before prescribing certain drugs will help curb addiction and prevent deaths. The state's controlled substances monitoring database has been around for several years, but its use has not been mandatory. Starting Jan. 1, doctors and others who prescribe drugs must register with the database. They will have to start checking it every time they prescribe certain powerful drugs, with limited exceptions starting April 1. Pharmacists will be required to update the database every seven days beginning Jan. 1. Currently, they are required to update it every 30 days. Drug overdoses killed more than 1,000 people in Tennessee last year making overdoses the single largest cause of accidental deaths in the state.