At the same time, just one in eight male prisoners were on methadone.
Over half of female prisoners are on methadone, which is normally used to treat an addiction to heroin.
There were 104 on the drug at the end of last year - out of 189 women in jail at the time.
According to freedom of information figures, only one in eight male prisoners were on methadone at the time.
Former governor of Mountjoy and Portlaoise Prisons, John Lonergan, is not surprised by the figures relating to women:
Midlands Gardaí Appeal For Witnesses To Fatal Crash
Two people died in the collision.
Midlands Security & Defence Analyst Says Hoax Bomb Threats Aimed To Intimidate
Newstalk, Today FM and RTÉ were sent the false alerts by email yesterday.
Almost €446,000 Allocated To Midlands Community Centres And Clubhouses
Ballinahown Community Hall received the highest amount in Westmeath.
Two People Killed In Offaly Following Fatal Crash
One person has been killed in the collision.
Midlands Family Takes On Ireland’s Fittest Family Challenge
The series continues this weekend.
5K Fundraiser To Support Motor Neurone Disease Association Takes Place In Westmeath
The event is taking place tomorrow.
No Slowing Down With Age As Westmeath Bowlers Shine At 14th Annual National Bowls Competition
Woman Appears In Court Over €280k Cannabis Seizure In Midlands
20kg of cannabis was discovered in the vehicle on the M7 in Portlaoise.
