Harmen Beurmanjer

70 Chapter 5 Subjective withdrawal symptoms LMM analysis showed that patients reported a decrease in withdrawal symptoms (SWS) over time during the detoxification (main effect of time: F(6,11)=6.481, p<.003). Patients in the pharmaceutical GHB group had lower SOS scores (mean=15.90; SD=13.83) than those in the BZD group (mean=36.50; SD=21.08), indicating less severe withdrawal in the GHB group (main effect of group: F(1,1688)=42.336, p<.001), see Figure 1. No interaction effect between group and time was found. Since BZD tapering lasted seven days on average the comparison of subjective withdrawal shown in only over the first seven days of detoxification. The results did not differ when the full eleven days pharmaceutical GHB tapering were included in the analysis. Table 1 Patient characteristics of BZD and pharmaceutical GHB detoxification groups BZD (n=42) Pharmaceutical GHB (n=42) p Male: n (%) 29 (69.0%) 31 (73.8%) p=.801 Age: years (sd) 30.5 (5.5) 28.7 (5.6) p=.130 Months of daily GHB use (sd) 44.8 (46.4) 51.1 (33.4) p=.493 Daily ml GHB (sd) Co-morbid substance use (In past thirty days) -nicotine -stimulants -alcohol 76.7 (61.9) 92.3% 76.0% 55.6% 75.7 (52.4) 94.2% 59.1% 60.4% p=.953 p=.702 p=.090 p=.637 Table 2 Tapering doses of pharmaceutical GHB in grams in the Netherlands, and diazepam in milligrams in Belgium. Day Average GHB dose in grams (SD) Average diazepam dose mg dose (SD) 1 28.24 (10.51) 60.32 (38.61) 2 25.01 (10.07) 100.34 (64.15) 3 22.13 (9.83) 74.16 (45.77) 4 19.60 (9.24) 63.55 (27.95) 5 18.08 (8.68) 51.86 (25.44) 6 16.12 (8.38) 44.74 (38.10) 7 14.02 (6.47) 33.74 (29.76) 8 11.56 (5.94) 9 8.46 (5.66) 10 6.28 (6.93) 11 4.80 (3.25)