More than 1.5 million of the Republic's residents could be paying too much for their family's medicines, according to figures from the General Medical Services (Payments) Board, the body responsible for administering community healthcare payments.

The board has found that 2.6 million people are eligible to register for the Drugs Payment Scheme, a system under which no registered individual or family should pay any more than £42 (€53.33) for prescription medicines in one calendar month.

Of those eligible, however, fewer than half have actually signed up under the system.

Around 1.5 million potential patients are either unaware of the scheme or have decided that it's not worth the time it takes to fill in the relevant registration forms. Either way, an examination of the figures involved suggests that it might be worth their while to reconsider this position.

Anyone who has raised a baby through childhood and into teenage years knows all about the often frightening costs attached to prescription medicines: think of the creams for nappy rash, drops for eye infections, anti-inflammatory drugs for that broken leg, arm or wrist.

It can all turn out to be an expensive business if you're not organised.

A course of one acne gel could set you back as much as £20 for example, and if you're the parent of three teenagers not blessed with clear skin, it will quickly add up.

The Drugs Payment Scheme was introduced by the Government in 1999 as a response to the burdensome costs that a sickly family can incur at the local pharmacy.

The scheme imposes a £42 maximum threshold on prescription medicine costs and allows for all additional charges to be refunded to the nominated patient involved.

While £42 will figure as a significant entry in the average family's monthly budget, it pales beside the £75 bill the same family could face if three members required high-strength antibiotics in the same month. Just one course of Losec, a drug commonly prescribed for stomach disorders, could cost as much as £65.

Losec's main ingredient, omeprazole, appeared on the Drugs Payment Scheme books 201,000 times last year.

The scheme will cover a nominated adult, his or her partner and all children aged under 18. Dependants who are over 18 but under 23 and in full-time education may also be included, as may be dependants of any age who are unable to fully care for themselves as a result of illness. The scheme can be used in conjunction with the long-term illness programme, which applies to patients suffering from conditions such as diabetes, epilepsy or cerebral palsy.

Last year, Aspirin was the drug most commonly prescribed under the scheme.

Registration for the scheme could hardly be easier: straightforward forms can be requested from local health boards and once they have been returned and processed, patients are issued with a swipe card to reflect their registration. In the future, the Payments Board plans to activate electronic terminals in each pharmacy that will identify patients through their cards and provide access to a central database of information on the scheme.

In the meantime, however, patients must attend the same pharmacy for the duration of the month for their participation in the scheme to be effective.