One of the biggest barriers to antidepressants coming to the market is that the
medical insurance system in Japan is national, and the authorities are keen to contain a potentially explosive market for drugs like antidepressants that, from the Japanese perspective, could be used or abused by persons in various forms of distress.[2]
Although large
epidemiological studies have not been done in Japan, it is thought that up to 6 million Japanese suffer from
depression, with a lifetime prevalence of 13 to 17.3%, which is similar to that seen in Western countries.[2]
Prior to year 2000 and possibly even later, clinical developments did not use placebo controlled trials; instead they have pitted candidate drugs against those currently approved for that indication using a "non-inferiority" method of comparison. This method is known to be subject to placebo effects (e.g. depressive symptoms lifting due to effects other than
pharmacologic drug effect.)[2] According to a Japanese medical report in 2002,
Trazodone and
tricyclic antidepressants (TCAs) were widely available in Japan while only two
SSRIs (
paroxetine and
fluvoxamine) were marketed.[4]
Fluvoxamine was the first SSRI to be approved in Japan (1999).[5][6]Sertraline received approval in April 2006, having been pending approval for over 15 years. [7][8]
Currently (as of 2017) the three most sold antidepressants in Japan are duloxetine, mirtazapine, and escitalopram (Lexapro).[9]
The three most sold antidepressants by the end of 2010 were
paroxetine with a value market share of 37%,
sertraline with a share of 20% and
fluvoxamine with a share of 15%.[10]
The Japan algorithm for
mood disorders[11] does not include many of the post-tricyclic antidepressants used as first-line antidepressants in Western countries for almost two decades, and recent studies are still comparing
SSRIs and
tricyclic antidepressants, even though tricyclics are 2nd or 3rd line treatments in the West.[12]Organon International and
Meiji Seika have filed an application for approval of
mirtazapine in Japan, a drug on the market in many Western countries since 1994.[13]Meiji Seika is commercializing
mirtazapine (brand name Reflex)[14][15] in
Japan which was approved for
depression in 2009.[16]
SNRIDuloxetine(Cymbalta - Shionogi and Eli Lilly Japan) was first approved in Japan in 2010 for
major depressive disorder.[17][18] In the following years it gained approval for diabetic neuropathy pain, fibromyalgia, chronic low back pain and osteoarthritis.[19][20][21][22]
Citalopram (Lundbeck), an SSRI on the market since the late 1980s is not available in Japan; however on April 22, 2011
escitalopram (the S-isomer
enantiomer of
citalopram), was approved for use.[23] There is little news, however, on the status of
bupropion (
Glaxo Smith-Kline), used widely in Western countries since the early 1990s and long in clinical trials in Japan.
^Nomura S, Sawamura T, Kobayashi N, Yoshino A (Sep 2004). "Medication algorithm for mood disorders: Present status and future direction in Japan". International Journal of Psychiatry in Clinical Practice. 8 (3): 139–45.
doi:
10.1080/13651500410005432-1.
PMID24926843.
S2CID8210423.
^Otsubo T, Akimoto Y, Yamada H, et al. (Jan 2005). "A comparative study of the efficacy and safety profiles between fluvoxamine and nortriptyline in Japanese patients with major depression". Pharmacopsychiatry. 38 (1): 30–5.
doi:
10.1055/s-2005-837769.
PMID15706464.
S2CID25949175.
^Products Approved in FY 2009: New Drugs.
"List of Approved Products"(PDF). Pharmaceuticals and Medical Devices Agency.{{
cite web}}: CS1 maint: numeric names: authors list (
link)