The HSE has issued an alert on stimulant drugs which have been implicated in the deaths of two people in the past four days and others in the past four weeks, as well as a number of hospitalisations.

The HSE said while investigations were ongoing into these cases, it was believed that they were as a result of the ingestion of an ecstasy-like substance. Green Apple and Green Rolex (green pills with an apple or rolex symbol) appear have to been implicated in some of these incidents, it said.

Other stimulants indicated include cocaine and amphetamines, which in some circumstances have been taken in combination.

"Therefore, those who take drugs should be specifically warned of potential dangers linked to these substances or using drugs in combinations," the HSE said.

People who have taken the drugs suffer from severe agitation, extremely rapid heart rate and extremely high temperature.

"Even with prompt medical attention, unfortunately some people have died taking these stimulants. There is sufficient evidence available to recommend that people do not take these substances or if their friends are in possession of these that they should not be consumed," the HSE said.

The HSE Drugs & Alcohol Helpline is available Monday to Friday, 9.30am and 5.30pm.

This confidential service has both a freephone helpline (1800 459 459) and an email support service (helpline@hse.ie).