Relationship between plasma risperidone concentrations and clinical features in chronic schizophrenic patients in China

Table 1 Characteristics of sociodemographic and clinical variables

Characteristic (n = 50)	Minimum value	Maximum value	Mean value	SD
Age (yr)	38	69	58.38	8.31
BMI	16.02	36.05	23.95	4.82
Course of illness (yr)	15	51	33.32	9.18
Systolic blood pressure (mmHg)	90	180	130.08	18.21
Diastolic blood pressure (mmHg)	60	105	78.60	10.32
Heart rate (per min)	60	103	79.86	9.79
QTc	0.38	0.52	0.45	0.03
Mean PANSS positive subscale score	7	20	10.92	3.17
Mean PANSS negative subscale score	9	31	22.32	4.20
Mean PANSS general psychopathology subscale score	22	51	31.04	5.07
Mean PANSS total score	48	101	64.28	8.89
PHQ-9	0	9	1.82	1.64

BMI: Body mass index; QTc: QT interval; PANSS: Positive and Negative Syndrome Scale; PHQ-9: Patient Health Questionnaire Depression Scale.

Table 2 Risperidone dose and plasma concentrations of risperidone and 9 hydroxyrisperidone according to sex

	Sex	n	Average	SD	P value
Risperidone dose (mg)1	Male	32	4.09	1.12	0.003
	Female	18	3.11	0.90
	Total	50	3.74	1.14
Risperidone dose per kg weight2	Male	32	0.06	0.02	0.010
	Female	18	0.05	0.02
	Total	50	0.06	0.02
Concentration of risperidone in plasma (ng/mL)1	Male	32	8.61	10.80	0.134
	Female	18	15.13	15.27
	Total	50	10.96	12.83
Concentration of 9-hydroxyrisperidone in plasma (ng/mL)1	Male	32	32.37	18.63	0.887
	Female	18	29.24	10.25
	Total	50	31.24	16.07
Concentration of risperidone + 9-hydroxyrisperidone in plasma (ng/mL)1	Male	32	40.98	23.98	0.293
	Female	18	44.37	18.79
	Total	50	42.20	22.11
Concentration of risperidone + 9-hydroxyrisperidone in plasma/dose2	Male	32	9.87	4.18	0.010
	Female	18	14.89	6.96
	Total	50	11.68	5.81
Concentration of risperidone + 9-hydroxyrisperidone in plasma/(dose × kg)1	Male	32	0.16	0.07	0.017
	Female	18	0.24	0.12
	Total	50	0.18	0.10

¹Mann-Whitney U-test.

²Student's t-test.

Table 3 Correlation of average concentrations of risperidon + 9-hydroxyrisperidone in plasma/(dose × kg) according to sex with clinical and psychopathological variables

Correlation of average concentration in plasma/(dose × kg) with	Correlation coefficient	P value
Male (n = 32)
Age (yr)	0.4572	0.008
Number of cigarettes (smokers)	-0.3591	0.092
Systolic blood pressure	0.0962	0.600
Diastolic blood pressure	0.1262	0.492
BMI	-0.2711	0.134
Heart rate	-0.1731	0.344
QTc	0.0602	0.743
Mean PANSS positive scale score	0.1792	0.328
Mean PANSS negative scale score	0.3731	0.035
Mean PANSS general psychopathology subscale score	0.3891	0.028
Mean PANSS total score	0.4812	0.005
Female (n = 18)
Age	0.4361	0.071
Systolic blood pressure	-0.1732	0.492
Diastolic blood pressure	0.0242	0.925
BMI	-0.4462	0.064
Heart rate	0.1322	0.600
QTc	0.0592	0.816
Mean PANSS positive subscale score	-0.2541	0.310
Mean PANSS negative subscale score	-0.1302	0.607
Mean PANSS general psychopathology subscale score	0.3752	0.125
Mean PANSS total score	0.0642	0.801

¹Spearman’s correlation coefficient.

²Pearson’s correlation coefficient.

BMI: Body mass index; QTc: QT interval; PANSS: Positive and Negative Syndrome Scale; PHQ-9: Patient Health Questionnaire Depression Scale.

Table 4 Comparison between adverse drug reaction groups and non-adverse drug reaction group

	Trihexyphenidyl group (n = 10)	No trihexyphenidyl group (n = 40)	P/Z value
Risperidone dose per kg weight2	0.07 ± 0.03	0.06 ± 0.02	0.129
Concentration of risperidone in plasma (ng/mL)1	11.18 ± 11.98	10.90 ± 13.18	0.899
Concentration of 9-hydroxyrisperidone in plasma (ng/mL)2	42.94 ± 26.33	28.32 ± 10.98	0.117
Concentration of risperidon + 9-hydroxyrisperidone in plasma (ng/mL)2	54.12 ± 33.68	39.22 ± 17.52	0.205
Concentration of risperidon + 9-hydroxyrisperidone in plasma/dose1	11.77 ± 5.67	11.65 ± 5.92	0.923
Concentration of risperidon + 9-hydroxyrisperidone in plasma/(dose × kg)1	0.17 ± 0.08	0.19 ± 0.10	0.577
	Laxative drug group (n = 10)	No laxative drug group (n = 40)	P/Z value
Risperidone dose per kg weight2	0.06 ± 0.02	0.06 ± 0.02	0.667
Concentration of risperidone in plasma (ng/mL)1	11.87 ± 14.22	10.71 ± 12.65	0.971
Concentration of 9-hydroxyrisperidone in plasma (ng/mL)1	37.77 ± 28.34	29.61 ± 11.20	0.914
Concentration of risperidon + 9-hydroxyrisperidone in plasma (ng/mL)1	49.64 ± 36.20	40.35 ± 17.15	0.877
Concentration of risperidon + 9-hydroxyrisperidone in plasma/dose1	12.81 ± 6.25	11.39 ± 5.75	0.465
Concentration of risperidon + 9-hydroxyrisperidone in plasma/(dose × kg)1	0.19 ± 0.07	0.18 ± 0.11	0.607

¹Mann-Whitney U-test.

²Student's t-test.