The number of drug-related deaths in Ireland has increased from 431 in 2004 to 607 in 2011, according to the latest figures published by the Health Research Board (HRB).

365 of the deaths in 2011 were due to poisoning (ie overdose).

242 deaths were related to trauma, such as road traffic collisions, or medical causes, such as liver disease.

The 2011 figures show that there were ten more drug-related deaths than the previous year.

The HRB also says that from 2004 to 2011, 4,606 people died directly or indirectly from drug use in Ireland.

The HRB National Drug-Related Deaths Index provides the latest data about the nature and the extent of premature death due to problem drug and alcohol use in Ireland.

It makes a number of key findings:

- The number of poisoning deaths increased from 338 in 2010 to 365 in 2011.

- Almost two thirds of these deaths were male and men account for the majority of deaths since 2004.

- The median age for those who died was 39 and alcohol was involved in 37% of poisoning deaths in 2011, more than any other drug.

- Alcohol alone was responsible for 17% of poisoning deaths.

More than half of poisoning deaths involved more than one drug (polydrug). There was a notable increase (28%) in the number of poisoning deaths as a result of polydrug use, rising from 168 in 2010, to 215 in 2011.

The drugs most implicated in polydrug use are alcohol, diazepam, methadone and anti-depressant medication.

Heroin-related poisonings continue to decline from 72 in 2010 to 60 in 2011, while cocaine deaths have fallen from a peak of 66 deaths in 2007 to 23 in 2011.