The HSE has issued a warning in relation to stimulants following the death of two people in the last four days and a number of others in the past month.
The drugs which are called Green Apple and Green Rolex are green in colour, with an apple or rolex symbol on top.
Other stimulants, including cocaine and amphetamines, which in some circumstances have been taken in combination have also been implicated in the deaths and hospitalisation of people in recent weeks.
In the statement the HSE said the symptoms include severe agitation, extremely rapid heart rate and extremely high temperature.
The state body is warning that even with prompt medical attention some people have died from taking these stimulants.