In Reply:-We appreciate the interest of Drs. Gevirtz, Subhedar, and Choi in our recent publication. 
On the clinical side, consistent with our experience, clonidine reduces withdrawal symptoms during detoxification. Accordingly, it has been favourably administered during detoxification from opioids in awake addicts for more than 20 yr. However, it has been claimed by psychiatrists that cardiovascular responses and withdrawal symptoms to detoxification from opioids both can be minimized by administration of large amounts of [micro sign]-opioid receptor antagonists alone when administered during sedation or general anesthesia. [3,4]In our study, we had to reject this hypothesis by demonstrating extensive increases in catecholamine concentrations in plasma and cardiovascular stimulation associated with [micro sign]-opioid receptor blockade by naloxone during general anesthesia. Furthermore, the need for additional drugs such as [small alpha, Greek]2-adrenergicagonists, e.g., clonidine, was described. 
We pointed attention to the fact that (1) marked sympathoadrenal activation and cardiovascular stimulation may be observed during detoxification from opioids by administration of [micro sign]-opioid receptor antagonists alone, despite deep general anesthesia, and (2) the need for trained anesthesiologists/intensivists in performing this treatment, as also proposed by Dr. Gevirtz and coworkers. Whether and why clonidine helps in minimizing cardiovascular and sympathoadrenal stimulation during detoxification even during conditions of general anesthesia is the subject of ongoing investigation.
Peter Kienbaum, M.D.
Research Fellow and Resident
Jurgen Peters, M.D.
Professor of Anesthesiology and Intensive Care Therapy and Chairman; Abteilung fur Anasthesiologie und Intensivmedizin; Universitatsklinikum GH; Essen, Germany;firstname.lastname@example.org
(Accepted for publication September 17, 1998.)