1 Selective serotonin reuptake inhibitors (SSRI) – sales, withdrawal ...

128 M. Nielsen and P. Gøtzsche / An analysis of psychotropic drug sales
Sales of benzodiazepines peaked in 1986 (Fig. 2). Thereafter, there was a pronounced decline in sales
that became less pronounced from about 1995, coinciding with increased availability of benzodiazepinelike
drugs (N05CF) on the market.
Sales figures for the specific neurotransmitter reuptake inhibitors (N06AB and N06AX) separately
were available from 1992. The recent steep increase in sales in ATC group N06 was entirely due to
increased sales of these drugs (Fig. 2).
From 1992 to 2007, DDD for the SSRIs increased from 2.5 to 43.9, i.e. by a factor of 18. A closely
similar increase was seen in the number of different SSRI products on the Danish market, including
brands and generics, which increased in the same period from 3 to 47, i.e. by a factor of 16 (r = 0.97 for
the correlation) (Fig. 3). Twenty-three different drug companies marketed the 47 different products in
Denmark in 2007. The number of indications for treatment with SSRIs increased from 1 in 1992 to 8 in
2008.
In contrast to the SSRIs, there seemed to be no relation between sales of benzodiazepines and
benzodiazepine-like drugs and number of products on the market. Sales started dropping in 1986 whereas
number of products continued to increase up to 1996, where it peaked with 48 products, and then declined
(Fig. 4). The number of indications increased from 8 in 1983 to 11 in 2005.
120
100
DDD/1000 inhabitants /day
80
60
40
20
0
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
Year
Total benzodiazepines
Total neurotransmitter reuptake inhibitors
1992
1994
1996
1998
2000
2002
2004
2006
Fig. 2. The total sales of specific neurotransmitter reuptake inhibitors and total benzodiazepines and benzodiazepine-like drugs
1970–2007.