The Irish Nurses and Midwives Organisation has announced two additional dates for strike action.
The decision was made at a meeting of the unions executive council today, and will see members down tools on the 19th and 21st of February.
The stoppages will be in addition to strike dates already planned for the 5th, 7th, 12th, 13th and 14th.
Last Wednesday saw the first of the 6 original 24 hour stoppages take place, in the row over pay and staff shortages.
An increase in the number of services on strike from 82 to 240 was also announced for the 5th and 7th.
In a statement, the INMO General Secretary Phil Ní Sheaghdha said:
"Nurses and midwives proudly stood up in defence of our patients and professions last Wednesday, but the government has responded with threats and intransigence.
"Everybody - except the government - recognise that there is a serious understaffing problem in our health services. The public support for the strike on Wednesday showed that the Irish people stand with nurses and midwives.
"Our message is clear. We will not be going away - resolving this dispute requires direct engagement from the government, recognising the real recruitment and retention problems in Irish nursing and midwifery.
"We simply want to be able to do our jobs, but our health service cannot hire enough nurses and midwives on these uncompetitive wages.
"As ever, we remain available for talks with the government for any realistic proposals."
A national rally organised by the union will also be held on Saturday 9th of February.