Therapeutic drug management
Trough levels are the most reproducible
Dk green heparin (Li or Na), no gel
Immediately following collection, mix sample thoroughly by gently inverting 5 - 10 times, to prevent clotting
Refrigerated (preferred)
Ambient (OK) - 3 days
Frozen (OK)
Gel-barrier tubes are not recommended
Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)
Venlafaxine: 100 - 500 ng/mL
Desmethylvenlafaxine: 200 - 400 ng/mL
Not established