Possible Interaction: Monoamine Oxidase Inhibitors and Tryptophan

“…,tryptophan, … monoamine oxidase inhibitor (MAOI).1-4However, some of these studies also involved the use of methionine.3-5Tryptophan has been shown to potentiate the antidepressant effects … studies.9-12 Although some of the above studies were of longitudinal type, they were not conducted on patients with periodic illness.”

“Drs OLAV SPIGSET and TOM MJORNDAL (Division of Clinical Pharmacology, Umea University Hospital, Sweden) and Dr OLOF LOVHEIM (Department …: The serotonin syndrome is a potentially lethal, toxic hyperserotoninergic state, most commonly resulting from an interaction between irreversible, non-selective monoamine oxidase inhibitors and agents increasing … reuptake inhibitors or tryptophan.'”

“Drs OLAV SPIGSET and TOM MJORNDAL (Division of Clinical Pharmacology, Umea University Hospital, Sweden) and Dr OLOF LOVHEIM (Department …: The serotonin syndrome is a potentially lethal, toxic hyperserotoninergic state, most commonly resulting from an interaction between irreversible, non-selective monoamine oxidase inhibitors and agents increasing … reuptake inhibitors or tryptophan.'”

“In four studies, all carried out more than 20 years ago, the combination of tryptophan plus a monoamine oxidase inhibitor was significantly better than tryptophan plus placebo in the treatment of depression.”

“Side effects of the combination of tryptophan and a monoamine oxidase inhibitors have limited the use of this combination.”

“Three cases are presented on patients on an MAOI who developed a transient syndrome of myoclonus, hyperreflexia, jaw quivering, teeth chattering and diaphoresis after L-Tryptophan was added.”

“The combination of monoamine oxidase inhibitors and tryptophan --a recognized antidepressant regimen--has been reported to cause behavioral or neurologic toxicity.”

“The author presents two cases of hypomania following the addition of L-tryptophan to an MAOI.”

“The combination of L-tryptophan and a monoamine oxidase inhibitor (MAOI) has been reported to be an effective antidepressant regimen.”

“The reports by Coppen et al. (1963) and by Pare (1963), that tryptophan was capable of potentiating the antidepressant action of monoamine oxidase inhibitors , were followed by the claim of Coppen et al. (1967) that tryptophan, given alone was as effective as electroconvulsive therapy in the treatment of depression.”

“The combination of monoamine oxidase inhibitors and tryptophan (Coppen et al., 1963; 1967), and tricyclic antidepressants e.g., chlorimipramine and tryptophan (Walinder et al., 1975), may increase 5-HT concentrations at receptor sites and therefore be more effective as an antidepressant than tryptophan alone.”

“It is suggested that 5-H.T.P. plus carbidopa, L-tryptophan plus a monoamine-oxidase inhibitor , and clonazepam may all act by elevating brain levels of serotonin (5-H.T.) and that some human myoclonic syndromes may be specifically related to a cerebral deficiency of 5-H.T.”