A report from the Health Research Board (HRB) says more heroin users are injecting the drug - resulting in a rise in infectious diseases and overdoses.
Opposition politicians have strongly criticised the Government for failing to deal with the problem.
The HRB report said that new cases in the seven regional health boards rose from two to 8.3 per 100,000 of the 15-64 year-old age group.
"There was a spread by county in demand for treatment for problem opiate use among new cases living in the seven health board areas, with very high rates of treated problem opiate use in counties Carlow, Cavan, Louth, Meath and Westmeath," said Dr Jean Long of the HRB. A breakdown shows the incidence on new cases was:
21.2 in Carlow in 1998-2002, compared to 9.7 in 1996-2000;
11.5 in Meath, compared to 7.4;
10.3 in Louth, compared to 5.0;
10 in Cavan, compared to 5.9;
16.8 in Westmeath, compared to 17.3.
Senior researcher at the HRB's Drug Misuse Drug Division Dr Long said there was a significant rise in other areas, including Longford, Roscommon and Cork. Figures on the prevalence on treated opiate use - reflecting the proportion of the population who have been treated for opiate use - show a rise from 6.6 per 100,000 in 1998 to 25.4 in 2002.
The report said there was an increase in the number of those injecting.
"Injecting leads to a higher risk of acquiring blood-borne viral infections and of experiencing overdose. This suggests that the incidence of blood-borne viral infections and opiate- related deaths has increased," said Dr Long.
The study said that cannabis was the most popular secondary drug used by heroin addicts.
The HRB wants more treatment facilities and harm-reduction services.
Fine Gael spokesman on drugs, Fergus O'Dowd, said the Minister of State for Drugs, Noel Ahern, had failed to tackle the heroin crisis.
He said the regional drug task forces (RDTFs), announced in 2001, were still only at research stage due to lack of staff and funding.
Mr Ahern said the four fold treatment increase was a "very positive development" as it showed treatment services were drawing in existing users.
He said research indicated that there were around 2,200 opiate users outside Dublin.
"The challenge has been to expand treatment facilities to cater for that population," said Mr Ahern.
He said he hoped the RDTFs would start implementing their action plans by mid-2005.