Monitoring drug therapy has changed markedly in the 15 years since the first edition of this book. Many new drugs are now monitored, particularly in immunosuppressant therapy and the treatment of epilepsy. Established drugs such as aminoglycoside antibiotics are now used very differently than they were in 1993, and an entirely new science - pharmacogenomics - has grown since the book was first published, and is already beginning to transform the way drugs are used. Some of the drugs deemed worthy of monitoring in the last century are now rarely encountered, having been replaced with more effective drugs which do not require the same degree of surveillance. We hope this new edition reflects these changes and will continue to prove useful to clinicians, pharmacists and laboratory scientists.