Possible Interaction: 5-Hydroxytryptophan and Monoamine Oxidase Inhibitors

“7 On the other hand, the administration of amine oxidase inhibitors , such as iproniazid (isonicotinylisopropylhydrazine) and pheniprazine ( β -phenylisopropylhydrazine) causes an increase in brain serotonin, 8,9 which is particularly evident with the concurrent administration of 5-hydroxytryptophan.”

“In the presence of a monoamine oxidase inhibitor, 5-hydroxytryptophan (5-HTP) administration blocked ovulation.?”

“On the other hand, a monoamine oxidase inhibitor enhanced the increase of tyrosine aminotransferase activity by serotonin or 5-hydroxytryptophan.”

“One approach to the study of the specificity of the antagonistic relationship between serotonin and copulatory behaviour has been selectively to increase serotonin by the combination of a monoamine oxidase inhibitor and the serotonin precursor 5-hydroxytryptophane (5-HTP).”

“It was found that the conversion of 5-hydroxytryptophan was influenced by both types of monoamine oxidase inhibitors but the non-hydrazine inhibitors were most effective.”

“It was shown also that the morning peak in 5-HT could be increased and retained by prior injection of 5-hydroxytryptophan and a monoamine oxidase inhibitor (beta-phenylisopropylhydrazine).”

“The hypothesis that an excess of serotonin in brain may be responsible for the effects of LSD stemmed from the observations on animals administered 5-hydroxytryptophan after pretreatment with an aniine oxidase inhibitor.”