It was still not clear last night what caused the overdoses after initial results from the Forensic Science Laboratory confirmed the women had smoked cannabis resin and cannabis herb. The tests did not find any contaminants.

Gardaí believe one of the women also sniffed aerosol deodorant and that this, combined with the cannabis, may have triggered respiratory failure.

The second case is still a mystery and detectives are investigating whether or not the cannabis she consumed may have same form of synthetic cannabis in it.

Sources said it was also possible the cannabis in the second case also contained synthetic cannabis.

Gardaí and HSE are still awaiting the results of tests of urine and blood samples from the women which are being examined by the state laboratory.

Officers will also endeavour to speak to the two women now that they are out of danger.

Louth mothers Alannah Molloy, 22, and Samantha Morgan, 24, were rushed to hospital and placed in intensive care after suffering extreme reactions to substances they had consumed.

Ms Molloy, from St Oliver’s Park, Kilsaran, was brought to hospital on Monday, while Ms Morgan, from Yellowbatter, Drogheda, was taken to hospital on Wednesday. Their condition was very poor and their families had been braced by doctors for the worst.

Ms Molloy has a 5-year-old boy, while Ms Morgan gave birth to her son seven months ago.

“The two women are off their ventilators and are conversing with families,” said a source last night.

“They are stable and out of danger.”

The two women are not thought to be known to each other.

Public health experts yesterday reminded drug users of the dangers of taking unregulated substances.

“There’s no such thing as risk free drug taking,” said Prof Joe Barry of the department of public health in Trinity College Dublin.

Gardaí in Co Louth, backed up by the Garda National Drugs Unit, will continue to investigate whether any synthetic cannabis may have been involved.

Drug sources in the North-east said there have been reports from some users of cases where cannabis resin has been sprayed with something.

There are reports from Europe of cannabis herb and resin being sprayed with synthetic chemicals which mimic cannabis in order to boost its potency.