The Irish Pharmaceutical Union has warned the public against buying medicines on the Internet.
Speaking at the organisation's annual general meeting in Gort, Co Galway, outgoing president Mr Brendan Quinn said "serious consequences" could accrue from buying drugs on-line.
He said that a recent Swiss study showed 18 out of 20 drugs ordered by this means had something wrong with them.
Mr Quinn warned that medicines available here only on a doctor's prescription could be purchased without one on the Internet. Moreover, Internet drugs were unlicensed, unlike medicines sold through pharmacies which had to receive product authorisation from the Irish Medicines Board.
Customers might think they were ordering from a "safe" country but they had no guarantee about where the medication originated. Purchasers also had no comeback if problems arose.
Moreover, the information leaflets with Internet medicines could be inadequate or in the wrong language. Without knowing it, the purchaser could end up taking a double dose if the medication contained the same active ingredient as another product which he or she was already using.
In his address to the conference, Mr Quinn also called for the better communication of facts on herbal medicines to "eliminate misconceptions and untruths".
He said: "Healthcare professionals are becoming more aware of side effects, interactions, and the toxicity of these entities. At the same time, they are learning about the therapeutic roles such products could and should play, if correctly managed."
"We must encourage research and understanding of this complex field. However, it is best that caution is exercised by the regulatory authorities in the form of sales restrictions on many herbals/natural remedies until such time as the sellers, suppliers, producers and prescribers come under better regulatory control.
"As is the case in all health disciplines, the actions of the uncontrolled, commercially oriented outlets drag down the reputation of the professional, and there is at present no way of discerning one from the other."
Ms Marie Hogan, a Limerick pharmacist, was elected to succeed Mr Quinn as president of the union at yesterday's meeting. She is the first woman president in the organisation's 26-year history.
