The Shelby County Health Department said Wednesday that 16 people suffered suspected overdoses during the 24-hour period ending midnight Sunday.
Officials said five overdoses resulted in deaths. They said the number of deaths is the highest for a single day since the Memphis-based department began using the Overdose Detection Mapping Application Program in July 2018.
The program tracks overdose reports from first responders and law enforcement agencies.
Department spokeswoman Joan Carr said tests will determine what kinds of drugs led to the suspected overdoses.
Health departments and law enforcement agencies in Tennessee and elsewhere are using data collection, aggressive prosecution and other methods to reduce overdoses from opioids and other drugs.