Tallaght Hospital Chief Executive Eilish Hardiman has said patient services will not be affected by the hospital's cashflow problems.
Last night, the Dublin hospital confirmed that it had obtained an overdraft facility of over €12 million from Allied Irish Banks, which will secure its cash flow to the end of the year.
Speaking on RTÉ's Morning Ireland, Ms Hardiman said Tallaght had changed its "model of care" and was treating patients more quickly.
Ms Hardiman said the hospital was admitting surgery patients only on the day of their operations and reducing patients' length of stay.
In this way, she said, it was tackling its deficit without affecting its overall patient care.
She said the hospital was in the same position last year when it had to apply for a similar overdraft, however not all of it was drawn down.
Tallaght used €4m of that overdraft, which was then repaid in January out of its 2012 budget.
This year, the hospital was over its budget by more than €10m in July.
A letter of support was sought from the Health Service Executive for the overdraft.
In a statement last night, the hospital said it was managing its finances prudently and had made savings of 6% in its budget this year, despite a 5% increase in inpatient care.
Tallaght Hospital is one of around five major hospitals that is heavily over budget and last year was over budget by over €14m.
Meanwhile, Minister for Health James Reilly has said he is confident that patient safety at Tallaght Hospital will not be affected by the fact that the hospital has to take out an overdraft of €12m.
Asked about the expected shortfall of over €1bn between cuts and over runs in the health service, he said they were preparing the budget for next year and they would have to look at the cost base.
Mr Reilly said the consultant arrangements would yield at least €200m but there was other work to be done in relation to the working week.