Abstinence phenomena of chronic cannabis-addicts prospectively monitored during controlled inpatient detoxification: Cannabis withdrawal syndrome and its correlation with delta-9-tetrahydrocannabinol and -metabolites in serum

Objective: To investigate the course of cannabis withdrawal syndrome (CWS) within a controlled inpatient detoxification setting and to correlate severity of CWS with the serum-levels of delta-9-tetrahydrocannabinol (THC) and, its main metabolites 11-hydroxy-delta-9-tetrahydrocannabinol (THC-OH) and 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH). Methods: Thirty-nine treatment-seeking chronic cannabis dependents (ICD-10) were studied on admission and on abstinent days 2, 4, 8 and 16, using a CWS-checklist (MWC) and the Clinical Global Impression-Severity scale (CGI-S). Simultaneously obtained serum was analysed to its concentration of THC, THC-OH and THC-COOH. Results: MWC peaked on day 4 (10.4 +/- 4.6 from 39 points) and declined to 2.9 +/- 2.4 points on day 16. Women had a significantly stronger CWS than men. The CWS was dominated by craving >restlessness>nervousness>sleeplessness. CGI-S peaked with 5 out of 7 points. On admission, THC and its metabolites did negatively correlate with the severity of CWS. There was no significant correlation afterwards, no matter if CWS was medicated or not. THC-OH in serum declined most rapidly below detection limit, on median at day 4. At abstinence day 16, the THC-levels of 28.2% of the patients were still above 1 g/ml (range: 1.3 to 6.4 ng/ml). Conclusions: CWS increased and then decreased without any correlation between its severity and the serum-levels of THC or its main metabolites after admission. According to the CGI-S, most patients achieved the condition of 'markedly ill'. Serum THC-OH was most clearly associated with recent cannabis use. Residual THC was found in the serum of almost one-third of the patients at abstinence day 16. (C) 2014 Elsevier Ireland Ltd. All rights reserved.