Venlafaxine

Concomitant use with linezolid (an MAOI) increases the risk of serotonin syndrome and is contraindicated.

Concomitant use is contraindicated. Avoid MAOIs 14 days before starting venlafaxine and 7 days after stopping.

Concomitant use with intravenous methylene blue (an MAOI) increases the risk of serotonin syndrome and is contraindicated.

Serious, sometimes fatal reactions reported when used concomitantly with MAO inhibitors.

SNRI concomitant use increases risk of serotonin syndrome. Monitor for signs and symptoms; discontinue if serotonin syndrome occurs.

Venlafaxine decreases oral-dose clearance of haloperidol by 42%, resulting in 70% increase in haloperidol AUC and 88% increase in Cmax.

Potential for serotonin syndrome with serotonergic drug lithium. Careful patient observation advised.

SNRI that increases risk of serotonin syndrome with mirtazapine. Monitor for symptoms during initiation and dose increases.

Potential for serotonin syndrome with serotonergic drug St. John's Wort. Careful patient observation advised.

Antidepressant that prolongs QT interval; should be avoided with toremifene citrate or requires close monitoring.

Potential for serotonin syndrome with serotonergic drug tramadol. Careful patient observation advised.

Potential for serotonin syndrome with serotonergic drugs including triptans. Careful patient observation advised.

Alcohol increases the release rate of Venlafaxine Extended-Release Tablets. Concomitant use should be avoided.

Concomitant use increases risk of serotonin syndrome. Monitor for symptoms and consider discontinuation if serotonin syndrome occurs.

Concomitant use may potentiate the risk of bleeding. Monitor patients closely for bleeding when initiating or discontinuing venlafaxine.

CYP2D6 substrate; bupropion inhibits CYP2D6 and increases venlafaxine concentrations; consider dose reduction.

Bupropion inhibits CYP2D6 and can increase venlafaxine concentrations; consider dose reduction of venlafaxine.

CYP2D6 substrate antidepressant. Bupropion inhibits CYP2D6, increasing venlafaxine exposure. Dose reduction of venlafaxine may be necessary.

CYP2D6 substrate. Bupropion inhibits CYP2D6 and can increase venlafaxine concentrations. Consider dose reduction of venlafaxine when used with bupropion.

CYP2D6-metabolized antidepressant. Bupropion inhibits CYP2D6 and can increase venlafaxine concentrations. Consider dose reduction.

Concomitant use increases risk of serotonin syndrome. Monitor for symptoms and consider discontinuation if serotonin syndrome occurs.

Cimetidine inhibits first-pass metabolism of venlafaxine, reducing oral clearance by 43% and increasing AUC and Cmax by 60%. Caution advised for patients with hypertension, elderly patients, or those with hepatic dysfunction.

SNRIs increase risk of serotonin syndrome when used with citalopram. Monitor for signs and symptoms of serotonin syndrome.

SNRIs increase risk of serotonin syndrome when used concomitantly with citalopram. Monitor for signs and symptoms of serotonin syndrome.

CYP2D6 inhibitor that increases haloperidol plasma concentrations; monitor for increased adverse effects including QTc prolongation.

CYP2D6 inhibitor that increases haloperidol plasma concentrations, raising risk of adverse events including QTc prolongation.

Cases of altered DATSCAN uptake that impacted image interpretation have been reported.

CYP2D6 and CYP3A4 inhibitor that increases venlafaxine and O-desmethylvenlafaxine AUC and Cmax. Caution advised.

Concomitant use increases venlafaxine and ODV levels, which may increase toxicity risk. Consider reducing venlafaxine dose.

( 7.7 ) Metoprolol: Possibly reduced blood-pressure lowering effect despite increased metoprolol plasma levels. Caution should be exercised with co-administration of venlafaxine and metoprolol. Metoprolol Concomitant administration of venlafaxine (50 mg every 8 hours for 5 days) and metoprolol (100 mg every 24 hours for 5 days) to 18 healthy male subjects in a pharmacokinetic interaction study for both drugs resulted in an increase of plasma concentrations of metoprolol by approximately 30% to 40% without altering the plasma concentrations of its active metabolite, α-hydroxymetoprolol.

Concomitant use may potentiate the risk of bleeding. Monitor patients closely for bleeding when initiating or discontinuing venlafaxine.

Increased venlafaxine exposure may occur; dosage adjustment may be needed.

Increased exposure of CYP2D6 substrate; decrease dosage if needed.

SNRIs increase risk of serotonin syndrome; monitor for signs and symptoms.

Concomitant use with tryptophan supplements not recommended due to serotonin syndrome risk.

No significant pharmacokinetic interaction observed. Diazepam did not affect venlafaxine or ODV pharmacokinetics, and venlafaxine did not affect diazepam psychomotor effects.

Co-administration did not result in significant pharmacokinetic changes or pharmacodynamic interaction between zaleplon and venlafaxine ER.

This finding was confirmed in vivo by clinical drug interaction studies in which venlafaxine did not inhibit the metabolism of several CYP3A4 substrates, including alprazolam, diazepam, and terfenadine.

Venlafaxine also did not have any effect on the pharmacokinetics of diazepam or its active metabolite, desmethyldiazepam, or affect the psychomotor and psychometric effects induced by diazepam.

Indinavir In a study of 9 healthy volunteers, venlafaxine administered under steady-state conditions at 150 mg/day resulted in a 28% decrease in the AUC of a single 800 mg oral dose of indinavir and a 36% decrease in indinavir C max . Indinavir did not affect the pharmacokinetics of venlafaxine and ODV.

In vivo , venlafaxine 75 mg by mouth every 12 hours did not alter the pharmacokinetics of a single 500 mg dose of tolbutamide or the CYP2C9 mediated formation of 4-hydroxy-tolbutamide.