Purpose: Fentanyliswidelyusedtorelievecancer
pain. Howeverthereisgreatinterpatientvariationin
the doserequiredtorelievepainandlittleknowledge
about thepharmacokineticandpharmacodynamic
(PK/PD) relationshipoffentanylandpaincontrol.
Patients withcancerarefragileandthereisreluctance
on thepartofhealthprofessionalstotakemultiple
plasma samplesforPK/PDstudies.Therelationship
between plasmaandsalivafentanylconcentrations
was investigatedtodeterminewhethersalivacouldbe
a validsubstituteforplasmainPK/PDstudies.