Plasma clozapine and norclozapine in relation to prescribed dose and other factors in patients aged 65 years and over: data from a therapeutic drug monitoring service, 1996–2010

摘要: Objective To investigate the effect of dose and other factors on plasma clozapine concentrations in patients aged 65 years over. Method Audit therapeutic drug monitoring data, 1996–2010. Results There were 1930 samples [778 patients, 363 men (median, range) 67 (65–100) years 415 women 68 (65–90) years]. There was no significant difference mean concentration between (0.56 mg/l) (0.58 mg/l), although higher (323 mg/d) than (264 mg/d). The proportion (46%) compared with (37%) smokers could explain this finding. Overall, 32% had below, 37% above, a target range 0.35–0.60 mg/l. median decreased from 300 (65–70 years) to 200 mg/d (age 85 years over). However, prescription >350 mg/d associated 50% likelihood that would exceed 0.60 mg/l. For subgroup 196 (114 men, 82 women), significantly after age 65 despite lower dosage. Conclusion Clozapine dosage elderly should be reviewed regularly minimise risk adverse effects. Copyright © 2012 John Wiley & Sons, Ltd.