More than 5,200 men, 103 in Kildare/West Wicklow, received opioid-substitution treatment in the first half of this year - mostly for heroin addictions.
A further 2,400 women, 58 in Kildare/West Wicklow, were issued with methadone, or similar drugs, in a community pharmacy.
More than half of the addicts were in Dublin, while Cork and Limerick were the next highest.
The details have been released under the Freedom of Information Act.
Dr. Austin O'Carroll - a GP in Dublin's inner city - says many more heroin addicts aren't accounted for in these stats: