Effexor development

Effexor (Figure 4.2) was developed by drug research scientists at Wyeth-Ayerst, John Yardley, Morris Husbands, and Eric Muth. Effexor development started in the early 1980s, at the same time Prozac was developed, but was released later than most of the other SSRIs, receiving FDA approval in 1993. 

Tricyclic drugs have, as the name implies, a three-ring structure, and interfere with reuptake of norepinephrine and/or serotonin into axon terminals. Tricyclic drugs include imipramine (Tofranil), amitriptyline (Elavil), clomipramine (Anafranil), and nortriptyline (Pamelor, Aventil). Tricyclics have the occasional but unfortunate cardiovascular side effects of arrhythmia and postural hypotension. Newer, nontricyclic antidepressants have been developed that are collectively referred to as SSRIs. These have a potent and selective action on serotonin, and lack the cardiovascular side effects of the tricyclics. These include fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft), and fluvoxamine (Luvox). A fifth SSRI, citalopram (Celexa) has been used in Europe and has recently been approved in the United States. Venlafaxine (Effexor) blocks reuptake of norepinephrine and serotonin, while bupropion (Wellbutrin) acts on both dopamine and norepinephrine. 

Along with this emphasis on particular disorders, recent pharmaceutical industry literature for conditions like depression and psychosis refers increasingly commonly to imbalances in brain chemicals, echoing the statements of official psychiatric literature described in Chapter 1. On depression, Eli Lilly s website claims that a growing amount of evidence supports the view that people with depression have an imbalance of the brain s neurotransmitters. .. many scientists believe that an imbalance in serotonin may be an important factor in the development and severity of depression (Eli Lilly 2006a, accessed 10.02.2006). Wyeth, makers of the antidepressant Venlafaxine (brand name Effexor... 

To make Effexor more convenient, Wyeth-Ayerst developed an extend-release version, called Effexor XR, which only needs to be taken once a day. 

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