The Isle of Man’s Public Health Directorate is warning heroin users about a batch of the drug that is particularly dangerous.

Heroin wmixed with fentanyl or other synthetic opioids is circulating in the north of England and in Northern Ireland.

The directorate says it is likely that it is also circulating in the Isle of Man.

Synthetic opioids are unusually potent and very small amounts can cause severe or fatal toxicity.

A PHD spokesman said: ’Heroin users should be extremely cautious about the sources of their drugs and should seek treatment and advice from the Drug and Alcohol Team.

’Carers, family and others in contact with heroin users should be vigilant for signs of overdose (loss of consciousness, shallow or absent breathing, "snoring", blue lips/fingers) and call an ambulance immediately.

’We would like to encourage any users not in contact with the Drug and Alcohol Team to seek support from the team to reduce their risk of harm from street drugs.’

Fentanyl is a synthetic opioid which is used on prescription to treat severe and terminal pain.

It can also be diverted to street supply and some versions are manufactured illicitly. It is about 100 times more potent than morphine.

Another version, carfentanyl is 4,000 to 10,000 times more potent than morphine and is used as an animal tranquilliser.

The spokesman added: ’The high potency of these opioids means that if a user does not realise they are present and uses what looks like their ’usual dose’ they are at high risk of overdose with potentially fatal consequences.

To contact the Drug and Alcohol Team phone 617889 or email [email protected]