Drugs-related health damage is a part of public health dealt with in Article 152 of the Treaty of Nice. Measures can be adopted by a qualified majority of the Council and co-decision in the EU Parliament.
The fight against the illegal cross-border sale of drugs is also a part of the Police co-operation in Europol.
The future
The EU Constitution proposes common safety concerns in public health as a shared competence - EU law would therefore suppress member states' existing legislation and right to legislate in this area.Links
http://www.europa.eu.int/scadplus/leg/en/s22001.htm