Table 2.

Dosage, plasma clozapine concentrations and comparison by gender, age and smoking status^*

Item	All samples (n = 193)	Male (n = 116)	Female (n = 77)	P	≤40 years old (n = 82)	>40 years old (n = 111)	P	Male smokers (n = 50)	Male non-smokers (n = 66)	P
Age	43.6 ± 11.4	41.7 ± 10.9	46.3 ± 11.6	0.006	33.3 ± 5.8	51.1 ± 8.1	<0.0001	40.5 ± 8.5	42.7 ± 12.5	0.268
Body weight (kg)	70.4 ± 11.6	72.5 ± 11.5	67.2 ± 11.1	0.001	70.2 ± 12.4	70.5 ± 11.0	0.859	71.8 ± 10.8	73.1 ± 12.5	0.572
Dosage (mg day−1)	296.9 ± 127.6	296.6 ± 128.1	296.3 ± 127.5	0.820	328.3 ± 123.5	273.7 ± 126.2	0.003	339.00 ± 134.9	264.4 ± 113.4	0.002
Dosage (mg day−1 kg−1)	4.35 ± 2.07	4.22 ± 1.97	4.58 ± 2.21	0.238	4.88 ± 1.97	3.62 ± 1.79	0.001	4.84 ± 2.13	3.74 ± 1.73	0.002
Clozapine (ng ml−1)	426.5 ± 283.0	386.0 ± 281.4	487.7 ± 276.1	0.001	471.4 ± 321.3	393.4 ± 247.4	0.143	432.1 ± 354.6	351.0 ± 206.1	0.442
Norclozapine (ng ml−1)	189.4 ± 119.5	176.1 ± 127.9	209.1 ± 103.5	0.002	211.7 ± 135.2	173.3 ± 104.4	0.032	207.9 ± 161.5	152.0 ± 89.2	0.073
Sum (ng ml−1)	617.6 ± 387.7	564.1 ± 393.2	696.7 ± 367.7	0.001	688.2 ± 442.8	566.7 ± 355.5	0.070	646.3 ± 504.3	502.2 ± 270.6	0.229
Normalized CLZ concentration†	23.96 ± 19.63	19.87 ± 3.55	30.09 ± 24.86	<0.001	22.01 ± 14.67	25.34 ± 22.60	0.257	18.06 ± 13.08	21.25 ± 13.85	0.194
Normalized NCLZ concentration†	10.08 ± 6.55	8.52 ± 4.30	12.43 ± 8.33	<0.001	9.67 ± 5.23	10.38 ± 7.38	0.462	8.29 ± 4.41	8.61 ± 4.22	0.704
Normalized sum concentration†	34.2 ± 25.6	28.55 ± 16.95	42.52 ± 32.71	<0.001	32.06 ± 19.25	35.74 ± 29.35	0.330	26.57 ± 16.86	29.90 ± 17.01	0.304
NCLZ/CLZ ratio	0.49 ± 0.22	0.51 ± 0.26	0.46 ± 0.14	0.262	0.49 ± 0.19	0.49 ± 0.24	0.986	0.54 ± 0.26	0.48 ± 0.26	0.229

^*All comparisons were performed using t-tests or Mann–Whitney U-tests (mean ± SE).

^†ng ml⁻¹ mg⁻¹ day⁻¹ kg⁻¹body weight. CLZ, Clozapine; NCLZ, norclozapine.