Medical card patients who may need two sets of tablets in order to make up the dosage they are prescribed by their doctor are also being hit by a double prescription charge.
Mr O Cuiv explained: "This anomaly means that many medical card patients can find themselves paying two prescription charges for one full dosage of medicine.
"For example, if a person requires a dosage of 30mg of Lipitor, they must purchase 10mg and 20mg tablets. The minister has confirmed to me that in this case, the person will have to pay €1.50 charge per item for the medicines, which means €3 in total for the one dose of tablets."
This will increase to €2.50 per item – and €5 in total – as a result of Budget 2014.
"This is another hidden charge by the Government, which seems to be piling charge after charge on people with lower incomes," he added.