The Monoamine Oxidase Inhibitor Isocarboxazid is a Relevant Treatment Option in Treatment-Resistant Depression-Experience-Based Strategies in Danish Psychiatry

Isocarboxazid is the only one of the classical monoamine oxidase inhibitors (MAOIs), which is marketed in Denmark. In 1980 a paper on long-term treatment of depression with isocarboxazid suggested that treatment with monoamine oxidase inhibitors like isocarboxazid should not be left untried in the case of therapy-resistant depression [1]. This is in accordance with the registered indication of the National Health Service of Denmark, however, nowadays worded as treatmentresistant depression (TRD) [2]. Also in the late 1970 a paper stated that “the use of MAOIs has been underutilized and a resurgence of interest in the MAOIs is timely” [3]. Meanwhile, in the era of newer antidepressants from the 1980 isocarboxazid was never routinely used. In 2013 the market share of isocarboxazid in Denmark accounted for only 262.000 defined daily doses (DDD ́s) (0.2%), which corresponds to about 400 patients. In comparison 151.601.000 DDD ́s (93.9%) were prescribed for use of SSRI (selective serotonin reuptake inhibitor) antidepressants and other newer antidepressants [4].