This paper provides a comprehensive overview of Paxil (paroxetine), a selective serotonin reuptake inhibitor (SSRI) approved by the FDA in 1992. It traces the drug's origins from 1960s Danish research through SmithKline's development and FDA approval, then explains its mechanism of action — blocking serotonin reuptake to increase synaptic availability. The paper reviews its approved indications, common and serious side effects, and key contraindications. A detailed clinical case study illustrates how Paxil is prescribed and titrated in practice for a patient diagnosed with recurrent major depressive disorder, including dosage adjustments, side effect management, and the physician's discussion of discontinuation risks.
In the 1960s, a Danish company named Ferrosan began performing research on aspects of the central nervous system. Ferrosan was most interested in the relationship between the neurotransmitter serotonin and depressed mood in people. The original idea was that if a drug could be developed to increase serotonin levels in the brain, it might lead to improvements in treating people with depression (DeGrandpre, 2006). The research resulted in the development of a formula for a compound then known as the "Buus-Lassen Compound," which allegedly had the capability to relieve depression. The compound was patented in the United States in 1977, and the company later sold all rights and research surrounding this patent to SmithKline (now GlaxoSmithKline) in 1980 (DeGrandpre, 2006).
SmithKline put significant effort into developing the compound, and much of this development occurred at the SmithKline plant in Harlow, England (DeGrandpre, 2006). Eventually, SmithKline patented a formula for paroxetine in the United States on October 23, 1986. Following the patent, paroxetine went through years of clinical trials. SmithKline gained FDA approval of the drug under the brand name Paxil on December 29, 1992 (DeGrandpre, 2006). The clinical trials for Paxil indicated that it was at least as effective as earlier tricyclic antidepressant drugs, but had fewer side effects (Anderson, 2001). It is the reduced side effect profile of Paxil and other selective serotonin reuptake inhibitors (SSRIs), along with their alleged ability to relieve depression, that have made them popular in the treatment of depression. Generic versions of Paxil have been available since 2003, when the patent on the original formula expired.
Paxil is one of the most potent and specific SSRIs. It blocks the reuptake of serotonin that has been released into the synaptic space (or anywhere else in the body where serotonin is used), and this leads to an increased availability of serotonin (Mellerup & Plenge, 1986). Paxil has been marketed by GlaxoSmithKline for the treatment of depression, obsessive-compulsive disorder (OCD), post-traumatic stress disorder, social phobia, and premenstrual dysphoric disorder (Sadock & Sadock, 2007). Paxil was the first SSRI to be approved for the treatment of panic attacks and panic disorder (Sadock & Sadock, 2007).
Paxil has also been investigated regarding its efficacy in treating premature ejaculation, although the research does not always indicate that it is effective for this purpose outside its noted side effect of reducing sex drive (Waldinger, Zwinderman, & Olivier, 2004). Other investigational studies have suggested that Paxil can be efficacious in treating conditions such as chronic pain (Weitzner, Moncello, Jacobsen, & Minton, 2002), tension headache (Langemark & Olesen, 1994), compulsive gambling (Kim et al., 2002), and diabetic neuropathy (Vieta et al., 1999).
Although the side effect profile of SSRIs is not as extensive as that of tricyclic antidepressants and MAO inhibitors, they often produce several side effects. A common side effect of SSRIs and of Paxil use is sexual dysfunction (Stahl, 2008). Sexual side effects most often consist of difficulty becoming aroused, ejaculatory disturbance, and sometimes a total lack of interest in sex. Sexual side effects are typically reversible once the medication is discontinued; however, in some people a post-SSRI sexual dysfunction occurs in which the side effects can last for months and even years following discontinuation (Stahl, 2008).
Nausea is one of the most common adverse side effects of treatment with Paxil (Stahl, 2008). Somnolence is another common side effect of Paxil use. Other common side effects include dry mouth, constipation, weight gain, agitation, dizziness, high blood pressure, headache, cognitive problems such as impaired memory, and paresthesia (Stahl, 2008). These side effects, when they occur, are typically present during the first four weeks of use and most often decrease after four weeks of usage (Stahl, 2008). Side effects are also dose-dependent.
Additional side effects that have been noted include hypomania, tremor, akathisia, and serotonin syndrome (Stahl, 2008). Although GlaxoSmithKline initially reported that discontinuation of Paxil did not produce any withdrawal symptoms, research has indicated that withdrawal symptoms do occur in individuals when SSRIs are discontinued (Stahl, 2008).
"Populations and conditions where Paxil is contraindicated"
"Patient diagnosed with major depression treated with Paxil"
"APA-formatted citations for all sources"
You’re 35% through this paper. Sign up to read the remaining 3 sections.
Sign Up Now — Instant Access Already a member? Log inAlways verify citation format against your institution’s current style guide requirements.