Paroxetine Cyproheptadine

Cyproheptadine Reports say that cyproheptadine can oppose the antidepressant effects of fluoxetine, fluvoxamine, and paroxetine. 

Clinically important, potentially hazardous interactions with amitriptyline, amoxapine, amphetamines, bupropion, citalopram, clomipramine, cyproheptadine, desipramine, dextroamphetamine, dextromethorphan, diethylpropion, dopamine, doxepin, entacapone, ephedra, ephedrine, epinephrine, fluoxetine, fluvoxamine, ginseng, imipramine, levodopa, mazindol, meperidine, methamphetamine, nefazodone, nortriptyline, paroxetine, phendimetrazine, phentermine, phenylephrine, pizotifen, propoxyphene, protriptyline, pseudoephedrine, rizatriptan, sertraline, sibutramine, sumatriptan, sympathomimetics, tramadol, tricyclic antidepressants, trimipramine, tryptophan, venlafaxine, zolmitriptan... 

Coadministration of the antihistamine cyproheptadine or other 5-HT antagonists with SSRIs might be expected to result in a pharmacodynamic interaction (i.e., reduced effectiveness for the SSRI). Cyproheptadine acts to block postsynaptic 5-HT. Lack of antidepressant efficacy has been reported when cyproheptadine was given concurrently with fluoxetine and paroxetine. 

A 21-year-old woman whose long-term treatment with paroxetine was stopped a week before starting venlafaxine (37.5 mg daily for 5 days then 75 mg daily for 2 days) developed vomiting, dizziness, incoordination, anxiety and electric shock sensations in her arms and legs within 3 days of starting venlafaxine. She stopped venlafaxine after 7 days of treatment, but symptoms persisted for 5 days until she was treated with cyproheptadine. ... 

Christensen RC. Adverse interaction of paroxetine and cyproheptadine, J Clin Psychiatry (1995) 56, 433-4. 

A 21-year-old man developed the serotonin syndrome when he took one tablet of paroxetine only one day after stopping desipramine, which he had taken for 5 days. He recovered after treatment with cyproheptadine. A woman taking paroxetine 30 mg daily developed the serotonin syndrome (tachycardia, delirium, bizarre movements, myoclonus) within 2 hours of taking a single 50-mg dose of imipramine. She recovered when treated with intravenous fluids, sedation and cyproheptadine. ... 

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