A controlled-release (CR) formulation of the SSRI paroxetine has been developed. 
This CR formulation delays the release of paroxetine until the tablet has passed 
through the stomach; the drug is then released over 4-5 hours. In well designed 
placebo-controlled trials in patients with major depressive disorder (including 
a study in the elderly), social anxiety disorder or premenstrual dysphoric 
disorder (PMDD), paroxetine CR was consistently superior to placebo with regards 
to primary endpoints (i.e. mean Hamilton Rating Scale for Depression total score 
[major depressive disorder], Liebowitz social anxiety scale total score and 
Clinical Global Impressions-Global Improvement score [social anxiety disorder] 
and Visual Analogue Scale-Mood score [PMDD]). The duration of treatment was 12 
weeks or, in PMDD, over three menstrual cycles (intermittent or continuous 
administration). Paroxetine CR also demonstrated efficacy in three well designed 
studies in patients with panic disorder with or without agoraphobia. Paroxetine 
CR was generally well tolerated in clinical trials, with an adverse-event 
profile typical of SSRIs, although recipients of paroxetine CR experienced 
significantly less nausea than recipients of immediate-release paroxetine in the 
first week of treatment.