This post is related to my post of 9 November 2012 (not yet translated) where I critically discussed some of the unscientific aspects of the chapter “psychotropic drugs” of the Drug Prescription Report (Arzneiverordnungsreport) 2012, which reports on the German drug market (authors: Lohse and Müller-Oerlinghausen). Today I want to specifically address the group of antidepressants.
Antidepressants are by far the most frequently prescribed psychotropic drugs. In 2011, 1257 million DDD (defined daily doses) were prescribed in Germany, almost 7% more than in 2010 (1176 million DDD). The group of selective serotonin-reuptake inhibitor (SSRI) with 572 million DDD represented almost one half of all prescriptions. Tricyclic antidepressants (named “non-selective monoamine reuptake inhibitors”, NSMRI, by the authors of the Drug Precription Report), with 292 million DDD, were still prescribed more often than serotonin-norepinephrine reuptake inhibitors (SNRIs) (174 million DDD). Prescriptions of the most commonly prescribed SSRI, citalopram, increased by approximately 23% from 2010 to 2011.
Prescription rates in DDD and net costs (per DDD in €, mean of all available preparations) of the most important SSRIs are as follows:
Citalopram: 338.7 Mio. DDD € 0.27
Sertraline: 64.4 Mio. DDD € 0.30
Fluoxetine: 51.6 Mio. DDD € 0.25
Paroxetine: 43.5 Mio. DDD € 0.26
Escitalopram: 36.0 Mio. DDD € 1.14
The preference of citalopram and sertraline, which have significantly less potential for drug interactions than fluoxetine and paroxetine, may be an expression of rational prescribing practices. Prescription rates of escitalopram decreased by 38% in comparison to 2010, which the authors correctly attributed to the classification of escitalopram in a reference price group by the G-BA. What they fail to mention is that this classification was abolished 2011 in court in December. Unfortunately, only a single paper from 2004 is cited, which questioned the superior efficacy of escitalopram over the racemic citalopram. Given the fact that there are now two Cochrane reviews that suggest that escitalopram is more effective than citalopram, one must consider this as a representation of at least negligence.
Among the tricyclic antidepressants, amitriptyline is the compound with the highest prescription rates:
Amitriptyline: 94.9 Mio. DDD € 0.36
Opipramol: 80.3 Mio. DDD € 0.37
Doxepine: 51.6 Mio. DDD € 0.43
Trimipramine: 32.2 Mio. DDD € 0.63
Amitriptylineoxide: 8.1 Mio. DDD € 0.19
Clomipramine: 7.6 Mio. DDD € 0.58
I absolutely agree with the authors on their sharp criticism of the extremely high prescription rates of opipramol in Germany. For the antidepressant efficacy of this drug virtually no evidence exists, and it is also more expensive than an SSRI.
The serotonin-norepinephrine reuptake inhibitors, especially venlafaxine, but also the still patent-protected and therefore relatively expensive duloxetine, have a significant market share in Germany and globally. This also applies to mirtazapine, the compound with the second highest prescription rate after citalopram:
Mirtazapine: 150.4 Mio. DDD € 0.50
Venlafaxine: 123.9 Mio. DDD € 0.71
Duloxetine: 40.7 Mio. DDD € 2.99
Agomelatine: 18.4 Mio. DDD € 1.83
Bupropion: 12.3 Mio. DDD € 0.98
Other antidepressants, including the monoamine oxydase inhibitor tranylcypromine (3.0 million DDD), play only a minor role. As already stated in my post dated 11/09/2012, the average price for venlafaxine is relatively high, because the expensive original drug (€ 1.94 / DDD) is still relatively frequently prescribed. The cheapest venlafaxine preparation is available for € 0.37, which is cheaper than any form of clomipramine.
Overall, the above-mentioned figures show that treatment with a newer antidepressant should not be more expensive than with a TCA. SSRIs are usually even cheaper than TCAs. Nevertheless, the tenor in this chapter of the Drug Prescription Report is that the latter would be preferable to the newer agents. With a biased citation of the literature and a somewhat opportunistic, industry-critical wording, some long-outdated prejudices are put forward, which can not withstand scientific evidence. The recent literature on key issues (such as triggering or amplification of suicidality with SSRIs, efficacy comparisons) is unfortunately incompletely cited. Many assertions are assigned anonymous, published in third-class journals. The above-mentioned example of the efficacy of escitalopram illustrates that the authors miss, unfortunately, to inform the interested reader truly objectively and differentiated about the available data. This is unfortunate, because the figures presented are highly valuable and deserve careful analysis. I advise readers of the Drug Prescription Report 2012 to look at the published numbers carefully, but build their own opinion based on the available literature.
Source: Lohse MJ, Müller-Oerlinghausen B: Psychopharmaka. In: Schwabe U, Paffrath D (Hrsg.) Arzneimittelreport 2012. Springer-Verlag Berlin Heidelberg 2012
This post is also available in: German