title: A review of the pharmacokinetic profile of transmucosal fentanyl formulations.
abstract: OBJECTIVE
  Breakthrough pain (BTP) is a transitory flare of moderate-to-severe pain that occurs in patients with stable, controlled persistent pain. Management of BTP episodes is difficult because frequency, time-to-peak intensity, and duration of episodes vary both within and between individuals. Formulations of fentanyl that use a buccal, sublingual, or nasal transmucosal route of administration have been developed for the treatment of BTP in opioid-tolerant patients with cancer. These formulations allow rapid passage into the bloodstream and avoid first-pass metabolism and, therefore, are more likely to match the time-course of BTP episodes than are oral formulations. The purposes of this analysis were to identify and review published data describing the pharmacokinetic properties of rapid-onset fentanyl formulations and to evaluate these properties in view of the temporal dynamic characteristics of BTP in order to help guide medical practice.
  
  
  METHODS
  Relevant publications were searched in the PubMed database from 1998. The plasma drug concentration-time profile of each formulation obtained from the identified studies was adjusted to a consistent scale for comparison.
  
  
  RESULTS
  The data revealed that the various transmucosal formulations resulted in three typical plasma fentanyl concentration profiles: (1) type 1: a very rapid rise and short duration; (2) type 2: a rapid increase and sustained intensity; and (3) type 3: a slower onset and longer duration.
  
  
  CONCLUSIONS
  Given the substantial variability of BTP episodes experienced by patients, these pharmacokinetic differences may provide useful information for a physician who is selecting a rapid-onset opioid medication for a patient.
authors.affiliation: Department of Pharmacology, Bordeaux 2 University, 33076 Bordeaux, France. nicholas.moore@pharmaco.u-bordeaux2.fr
authors.forename: Nicholas
authors.initials: N
authors.lastname: Moore
authors.forename: Mona
authors.initials: M
authors.lastname: Darwish
authors.forename: Xavier
authors.initials: X
authors.lastname: Amores
authors.forename: Hélène
authors.initials: H
authors.lastname: Schneid
mesh_terms: D000284:Administration, Oral; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D005283:Fentanyl / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D006801:Humans; D009061:Mouth Mucosa / Q000378:metabolism*; D010146:Pain / Q000188:drug therapy
chemical_list: D000701:Analgesics, Opioid; D005283:Fentanyl