Police across Europe have seized almost 300,000 doses of counterfeit anti-impotence and weight-loss medicines, highlighting the prevalence of fake drugs in the region.
Britain's Medicines and Healthcare products Regulatory Agency (MHRA) said on Tuesday that four people had been arrested in Spain and two in Britain following an international operation lasting several months.
In Britain alone the haul included tablets worth around $183,000 dollars, including counterfeit versions of Pfizer's Viagra and Eli Lilly's Cialis, both used to treat erectile dysfunction, as well as the withdrawn anti-obesity drugs rimonabant and sibutramine.
The risk posed by counterfeit medicines - which may be laced with dangerous chemicals or contain the wrong amounts of active ingredients or else none at all - were thrown into the spotlight by the recent discovery of fake versions of Roche's Avastin in the United States.
That case shocked regulators and the pharmaceutical industry since it showed criminals moving into the business of faking complex injectable drugs.
The World Health Organization estimates that less than 1 percent of medicines available in the developed world are likely to be counterfeit. Globally, however, the figure is around 10 percent, while in some developing countries as much as a third of medicines are estimated to be bogus.