As indicated in my response to Parliamentary Question No.589 of 19 February 2013, there are a number of ways in which prescription drugs can become available on the illegal market and steps are being taken to address this.
With regard to the further information sought by the Deputy, I am informed by the Garda authorities that the primary sources of prescription drugs being illegally sold in Ireland are as follows - internet based purchases; theft from legitimate industry; importation and distribution by organised criminal gangs and the misuse of prescriptions.
I am further informed that the estimated value of prescription drugs is calculated on the basis of the current market values of these drugs at street level in this jurisdiction. These values are subject to regular review by the Garda National Drugs Unit.