Isolated reports describe delayed hallucinations in a patient taking phenelzine and cyproheptadine, and the rapid re-emergence of 
depression when 
cyproheptadine was given to two other patients taking brofaromine or phenelzine. 
 It would be prudent to monitor for a reduction in 
efficacy or an adverse response if 
cyproheptadine is given with any MAOI or RIMA. The manufacturer of 
cyproheptadine contraindicates concurrent use with 
MAOIs, however, there appears to be no reason why 
cyproheptadine cannot be used to treat 
serotonin syndrome occurring in a patient taking an MAOI.