The coroner for NI has highlighted the "escalating crisis" of deaths linked to fake versions of the anti-anxiety drug, Xanax.
Joe McCrisken said that now he is signing off an alprazolam-related death nearly once a week.
He says "most of the deaths" are caused by counterfeit versions of Xanax, the brand name for the drug alprazolam.
Xanax is used to treat anxiety and panic attacks.
It is not available on the NHS and it is a powerful tranquiliser.
According to NHS Choices the drug is prescribed for General Anxiety Disorder.
The site says: "The name Xanax is a brand name for the drug, which is actually called alprazolam.
"It is part of the benzodiazepine group of prescription drugs, which also includes diazepam and lorazepam.
"Xanax isn't available on the NHS, and can only be obtained on a private prescription in the UK."
They add: "Xanax is a trade name for the anti-anxiety medication alprazolam.
"It is one of a group of addictive prescription medications known as benzodiazepines.
"Although Xanax is a prescription medication, it is also a controlled drug, which means it is illegal to take Xanax without a prescription from a medical doctor."