There has been a 50% decrease in the number of prescriptions made to people undergoing opioid-substitution treatment in the Sligo/Leitrim and Donegal areas so far this year.
In the vast majority of cases, this is used to treat heroin-addiction.
According to details released under the Freedom of Information Act, 33 people have received opioid-substitution prescriptions within the Sligo/Leitrim and Donegal areas in the first six months of this year.
This involved 12 men and 4 women in Donegal and 13 men and 4 women in Sligo and Leitrim.
The number of prescriptions made to people in Donegal since January is 341 with 387 dispensed in the Sligo/Leitrim area.
Although there looks to be a decrease in the number of prescriptions distributed compared to last year, the number of people receiving this type of treatment in Donegal and Sligo/Leitrim is set to increase.
33 people are already receiving opioid-substitution treatment within the first six months of this year compared to 37 people across the whole of last year.
Nationally, more than 7,600 people have received opioid-substitution so far this year with the highest in Dublin at nearly 4,500.