Conclusions : International differences in prescriber behaviour may influence , and in turn be influenced by , the conduct of clinical trials .
Objective : International differences are thought to exist in dosages used by clinicians treating mood disorders .
This study examined international dosage differences in antidepressant clinical trials , using a data base formed and maintained as a component of a Cochrane review of comparative clinical trials of fluoxetine .
A double-blind comparison of sertraline and fluoxetine in the treatment of major depressive episode in outpatients.
Depression is associated with considerable morbidity and mortality . As depressive disorders carry a high risk of relapse , treatment strategies include the use of a 6-month continuation period after resolution of the acute episode . Tolerability is of major importance when determining compliance and outcome during long-term therapy . Due to the superior tolerability profile of the selective serotonin reuptake inhibitors ( SSRIs ) over the older tricyclic antidepressants ( TCAs ) , the former may be more suitable for extended therapy . Comparative studies have not shown differences between the SSRIs in terms of efficacy , but side-effect profiles may vary . A multicenter , double-blind , comparative study of sertraline and fluoxetine was carried out in out patients fulfilling DSM-III-R criteria for major depressive disorder . Patients were r and omised to receive sertraline ( 50 - 150 mg , n = 118 ) or fluoxetine ( 20 - 60 mg , n = 120 ) for 24 weeks . Assessment s for depression ( HAM-D , HAD , CGI-I , CGI-S ) , anxiety ( Covi ) , sleep ( Leeds Sleep Evaluation scale ) and quality of life ( SIP ) were made at study entry and at weeks 2 , 4 , 8 , 12 , 18 and 24 . All adverse events were recorded to allow evaluation of tolerability . In total , 88 patients in the sertraline group completed the study compared with 79 in the fluoxetine group .  Side effects were responsible for the premature treatment withdrawal of seven ( 6 % ) sertraline patients and 12 ( 10 % ) fluoxetine patients . Two-hundred and thirty-four patients were included in an ITT analysis up to last visit ( 116 sertraline , 118 fluoxetine ) . At study endpoint , both treatments produced a significant improvement over baseline on all efficacy variables ( P < 0.001 ) . Although the magnitude of global changes in depression , anxiety , and quality of life was larger with sertraline than fluoxetine , none of the between-group differences reached statistical significance . However , significant differences in favour of sertraline were observed for individual HAM-D items including item 4 ( insomnia onset ) ( P = 0.04 ) , item 9 ( agitation ) ( P = 0.02 ) , and item 13 ( general somatic symptoms ) ( P = 0.008 ) . In addition , sertraline was associated with significantly superior performance on the Leeds Sleep Evaluation scale and on SIP items relating to sleep and rest , emotional behaviour and ambulation . Both sertraline and fluoxetine were well tolerated with no significant differences between treatments
Conclusions : International differences in prescriber behaviour may influence , and in turn be influenced by , the conduct of clinical trials .
Objective : International differences are thought to exist in dosages used by clinicians treating mood disorders .
This study examined international dosage differences in antidepressant clinical trials , using a data base formed and maintained as a component of a Cochrane review of comparative clinical trials of fluoxetine .