Monitoring for clenbuterol abuse in N. Ireland 1989-1994

Laboratory testing in N. Ireland for the illegal growth promoting agent, clenbuterol (CBL), is centralized at the Veterinary Sciences Division, Belfast. During the past 6 years a variety of testing schemes have evolved to determine the level of abuse of this drug in the local meat industry. The types of samples from cattle tested during this period altered as pharmacokinetic data for the compound increased. Initially, fluids such as urine and bile were used, however testing switched to more appropriate tissues such as liver, eyes, and hair. The first positive samples were detected in 1990, with 43 out of 121 samples tested showing detectable residues. In the following year, this number increased to 139 out of 286 tests. Despite substantial increases in the number of samples analysed over the succeeding years, the numbers of positive results steadily declined, thus giving strong evidence that abuse was also on the decline. From the data collected over the 6-year period, it became clear that the EU National Surveillance Scheme designed to detect abuse of illegal substances was ineffective and locally designed programmes were required to effectively tackle the problem.