SSRIs Dominate Depression Treatment -- But For How Much Longer?
According to Treatment Algorithms 1999: Segmenting the Depression Patient Population, a new report by Datamonitor (New York), the launch of third-generation antidepressants poses a considerable threat to the SSRIs in the United States. Overseas, for example in Japan (where economy is valued more highly and where many drugs are approved after they hit the U.S. marketplace), older, less-expensive tricyclic antidepressants still dominate.
Third-Generation Drugs Taking Over
Datamonitor's primary research with physicians in US, Japan, France, Germany, Italy, Spain, and the UK reveals that SSRIs currently dominate the treatment of depression in all countries, with the exception of Japan, where SSRIs are only just beginning to reach the market. It is generally agreed that there is little difference among the SSRIs in terms of efficacy and side effects.
However, number of newer treatments, including Wyeth's Effexor (venlafaxine), Akzo Nobel's Remeron (mirtazapine) and Pharmacia & Upjohn's Edronax (reboxetine), have been shown to have fewer side effects and more rapid onset times than the SSRIs. They are therefore considerably differentiated from the SSRIs, and can be expected to steal a significant proportion of new depression patients from even the leading SSRIs.
"The doctors interviewed are keen to try these newer treatments and commented that they expect them to significantly alter the prescribing patterns of the majority of physicians," said Datamonitor Analyst Christine Hollidge. "Given that the SSRIs take two to three weeks to take effect, the more rapid onset times of these new antidepressants make them particularly attractive to physicians."
Despite the relative novelty of third generation antidepressants, significant numbers of physicians are already prescribing them. Since these drugs meet physicians' (and patients') expectations for rapid onsent, they can be expected to do well, perhaps overtaking SSRIs in both prescription numbers and patient acceptance. Adds Hollidge, "The evidence indicates that the SSRIs may well suffer the same fate that they inflicted on the TCAs and MAOIs. From the patients' perspective, however, this can only be good news."
Japan Is Different
Japan is unusual among the major markets in that the only SSRI available is Solvay's fluvoxamine (Luvox), which was launched at the end of May 1999. The lack of SSRIs on the Japanese market means that TCAs dominate the treatments for depression in Japan. However, the doctors interviewed are keen to try products that are more effective and better tolerated than the TCAs.
The key drawback of the use of TCAs is that of adverse effects. Given that fluvoxamine has a better side effect profile than any of the TCAs available in Japan, the drug can be expected to have a rapid uptake. Furthermore, since Pfizer's sertraline, SmithKline Beecham's paroxetine and Bristol-Myers Squibb's nefazadone are likely to reach the Japanese market within the next five years, the prescribing patterns of Japanese physicians are expected to change to match the patterns observed in the other major markets.
The third generation antidepressants are a long way from the Japanese market and hence SSRIs are expected to dominate the treatments for depression in Japan for quite some time. However, Japan is merely one step behind the other major markets. The rise and fall of the SSRIs in the rest of the world is therefore also likely to occur in Japan, albeit sometime in the future.
For more information: Elisabeth Freeman, Datamonitor, 1 Park Ave., 14th Floor, New York, NY 10016. Tel: 212 686 7400, ext 165. Fax: 212 686 2626.
Angelo DePalma