Latest research on Paroxetine

Paroxetine hydrochloride and paroxetine mesylate belong to a class of antidepressant agents known as selective serotonin-reuptake inhibitors (SSRIs). Despite distinct structural differences between compounds in this class, SSRIs possess similar pharmacological activity. As with other antidepressant agents, several weeks of therapy may be required before a clinical effect is seen. SSRIs are potent inhibitors of neuronal serotonin reuptake. They have little to no effect on norepinephrine or dopamine reuptake and do not antagonize α- or β-adrenergic, dopamine D2 or histamine H1 receptors. During acute use, SSRIs block serotonin reuptake and increase serotonin stimulation of somatodendritic 5-HT1A and terminal autoreceptors. Chronic use leads to desensitization of somatodendritic 5-HT1A and terminal autoreceptors. The overall clinical effect of increased mood and decreased anxiety is thought to be due to adaptive changes in neuronal function that leads to enhanced serotonergic neurotransmission. Side effects include dry mouth, nausea, dizziness, drowsiness, sexual dysfunction and headache (see Toxicity section below for a complete listing of side effects). Side effects generally occur during the first two weeks of therapy and are usually less severe and frequent than those observed with tricyclic antidepressants. Paroxetine hydrochloride and mesylate are considered therapeutic alternatives rather than generic equivalents by the US Food and Drug Administration (FDA); both agents contain the same active moiety (i.e. paroxetine), but are formulated as different salt forms. Clinical studies establishing the efficacy of paroxetine in various conditions were performed using paroxetine hydrochloride. Since both agents contain the same active moiety, the clinical efficacy of both agents is thought to be similar. Paroxetine may be used to treat major depressive disorder (MDD), panic disorder with or without agoraphobia, obsessive-compulsive disorder (OCD), social anxiety disorder (social phobia), generalized anxiety disorder (GAD), post-traumatic stress disorder (PTSD) and premenstrual dysphoric disorder (PMDD). Paroxetine has the most evidence supporting its use for anxiety-related disorders of the SSRIs. It has the greatest anticholinergic activity of the agents in this class and compared to other SSRIs, paroxetine may cause greater weight gain, sexual dysfunction, sedation and constipation.

Latest findings

Paroxetine was successfully used in one patient with obsessive-compulsive disorder who withdrew to his room for 10 years but it is unclear whether this is marks true primary hikikomori (10). [source, 2016]
The antidepressant types were divided into three categories: i) selective serotonin reuptake inhibitors including Citalopram, esCitalopram, fluoxetine, Paroxetine, and Sertraline, ii) newer antidepressants such as Bupropion, Venlafaxine, and Mirtazapine, and iii) older anti-depressants such as Amitriptyline, Clomipramine, Imipramine, Milnacipran, Nortriptyline, tianeptine, and Trazodone. [source, 2016]
The most common SSRIs prescribed at baseline were Paroxetine (29.3%), fluoxetine (23.6%), Escitalopram (20.0%), and Sertraline (12.9%). [source, 2016]
The median daily doses of these medications at baseline were 20.0 mg/day for Paroxetine, 10.0 mg/day for Escitalopram, 50.0 mg/day for Sertraline, 20.0 mg/day for fluoxetine, and 60.0 mg/day for Duloxetine. [source, 2016]
Similarly, Thase et al,26 using pooled data from six RCTs, found that although Duloxetine and the two SSRIs (fluoxetine and Paroxetine) were comparably efficacious overall, treatment with Duloxetine was associated with higher remission rate in patients with moderate-to-severe depression (a HAMD17 score of ≥19). [source, 2016]
Although two SNRIs (Milnacipran and Duloxetine) and four selective serotonin reuptake inhibitors (Fluvoxamine, Paroxetine, Sertraline, and Escitalopram) have been approved in Japan as of August 2015, the maximum dosages for most of these are considerably lower than those used in western countries on the basis of balance between the benefits and risks in the Japanese population. [source, 2016]
For example, the maximum dosages approved in the US and Japan, respectively, for the treatment of MDD are as follows: Milnacipran (200 mg/100 mg), Duloxetine (120 mg/60 mg), Fluvoxamine (300 mg/150 mg), Paroxetine (50 mg/40 mg), Sertraline (200 mg/100 mg), and Escitalopram (20 mg/20 mg). [source, 2016]
Pharmacologic therapy may include selective serotonin reuptake inhibitor (SSRI) therapy (Citalopram, Sertraline, fluoxetine, dapoxetine or Paroxetine), phosphodiesterase type 5 (PDE5) inhibitor therapy (tadalafil or Sildenafil), topical desensitizing agents (prilocaine or Lidocaine) and other agents (Tramadol or Pindolol). [source, 2016]
Paroxetine is better than fluoxetine, Clomipramine and Sertraline in the treatment of PE. [source, 2016]
Doses of Paroxetine, Sertraline, fluoxetine and Clomipramine were 20 - 40 mg, 25 - 200 mg, 10 - 60 mg and 25 - 50 mg, respectively. [source, 2016]