Long-term illness: Thousands of people who could be getting their medicines free from the State every year are failing to avail of the benefit.
Figures provided by the Department of Health show some 50,526 people were registered as benefiting from the long-term illness scheme last year but that 93,504 people were actually considered eligible.
A spokeswoman said the discrepancy could be accounted for, in some instances at least, by people not claiming the benefit. Some of those listed as eligible may also have died, she said.
The news comes just days after Minister for Health Mary Harney confirmed the scheme would be reviewed.
She said the range of conditions covered by the scheme would be re-examined.
The scheme, which cost €85.5 million to administer last year, allows patients suffering from a limited number of lifelong conditions such as diabetes and cystic fibrosis to avail of free drugs.
Earlier this month a Dublin woman whose asthmatic daughter is on constant medication and requires hospitalisation several times a year urged the Government to consider extending the scheme in the Budget to cover chronic asthmatics.
Pauline Hazel from Glasnevin told the Health Supplement at the time that the financial burden of caring for Alison (15) was "too much to bear while trying to maintain a home with five other children".
The Department of Health at the time said it had no plans to amend the list of eligible conditions under the long-term illness scheme and the scheme remained unchanged following the Budget.
However, Ms Harney has now said it has been brought to her attention that the scheme hasn't been altered for 30 years.
"Nothing has been added to the scheme since 1975 . . . if something has not changed for 30 years there is something wrong with it or what we are doing," she told the Dáil health committee.
"I assume this area is governed by cost considerations. I have been informed that the extension of the scheme to cover asthma alone would cost €224 million," she added.
Asked by committee member Senator Geraldine Feeney if post-polio sufferers could be included in the scheme Ms Harney continued: "I know many individuals who suffer from general long-term illnesses and feel such illnesses should be included in the scheme.
"Perhaps the department should examine it to ascertain how it can be targeted at those who need it most in a more relevant way.
"If it has not been altered in 30 years it needs to be re-examined," she said.
The conditions covered by the long-term illness scheme at present are mental handicap, mental illness (for people under 16 only), phenylketonuria, cystic fibrosis, spina bifida, hydrocephalus, diabetes mellitus, diabetes insipidus, haemophilia, cerebral palsy, epilepsy, multiple sclerosis, muscular dystrophies, parkinsonism, conditions arising from thalidomide and acute leukaemia.