Prescription drugs such as benzodiazepines are implicated in the majority of deaths by overdose, according to data compiled by the Health Research Board.
By contrast, just 5 per cent of drug-related deaths are among people who inject drugs.
The figures are contained in the National Drug-Related Deaths Index for 2016, which gathers data on deaths due to overdose as well as deaths among drug users due to causes such as cardiac arrest or hanging.
Overall, prescription drugs were linked to seven out of 10 deaths, or 238, by overdose in 2016.
Benzodiazepines were the most common prescription drug group implicated in these deaths.
Source: Carl O'Brien, The Irish Times, 8th March 2019