A number of cancer patients being treated at Sligo University Hospital are affected by the shortages in chemotherapy drugs, while the HSE has confirmed to Midwest News that Mayo University Hospital and University Hospital Galway are not affected by the shortages.
It emerged earlier that Baxter Healthcare – the only firm supplying the medication to Ireland - ran short of supplies.
The HSE says it's a temporary reduction in supply, and it expects the capacity issue to be resolved by early next week.
While the hospitals in Mayo and Galway are unaffected by the shortage, a number of patients having treatment at Sligo University Hospital have had their treatment deferred.
The HSE says the Sligo hospital has an internal drug compounding facility but this is closed until next Tuesday for essential maintenance.
As a result, the hospital has had to defer treatment for 17 patients.
Management at the Sligo hospital say they regret the inconvenience and distress caused to patients, and hope to restore normal service next week.
Nationally, the HSE says only a small number of patients are affected by the drugs shortage, and that the vast majority of patients undergoing chemotherapy treatment will continue to receive treatment as per their planned schedule.