CHANGES IN SEROTONIN METABOLISM DURING TREATMENT WITH THE ALDEHYDE DEHYDROGENASE INHIBITORS DISULFIRAM AND CYANAMIDE

The effect of the aldehyde dehydrogenase inhibitors disulfiram (Antabu se(R)) and cyanamide (calcium carbimide, Dipsan(R)) on the metabolism of serotonin measured as relative amounts of the metabolites 5-hydroxy indole-3-acetic acid and 5-hydroxytryptophol in urine were studied in alcoholic patients. Sixteen out of 23 patients receiving drug therapy showed elevated excretion of 5-hydroxytryptophol. However, there was a marked, 15-fold, variability in 5-hydroxytryptophol excretion rate be tween patients. A high degree of variability was also seen in another group of patients studied before and after introduction of drug therap y. When patients were followed during the dose interval, a time-depend ent response after each single dose could be observed. The disulfiram response lasted over the course of several days whereas the response t o cyanamide lasted for less than 12 hr. It is concluded that treatment with disulfiram and cyanamide affects serotonin metabolism leading to increased production of 5-hydroxytryptophol, but there is a marked in ter-individual variability in degree of response.