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AimsIt is estimated that two-thirds of cancer patients will at some point during their illness experience breakthrough pain. In this study, the pharmacokinetics of a novel sublingual dosage form of fentanyl developed for breakthrough pain was evaluated. MethodsEleven Caucasian patients (seven male and 4 female, aged 34-75 years, median 60 years) with metastatic malignant disease were recruited initially, but three patients withdrew. Prior to the study all patients were on continuous nonfentanyl opiate medication. The study was a double-blind, cross-over trial, consisting of three 1-day treatment periods. A new rapidly dissolving preparation of fentanyl, was administered sublingually in single doses of 100, 200 and 400 m g, respectively, on three separate occasions. Plasma fentanyl concentrations were determined using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/ MS). Pharmacokinetic parameters were calculated by noncompar tment analysis. Tolerability and the occurrence of adverse events were monitored throughout the study by patient questionnaire. ResultsThe data from nine subjects who completed at least two periods were used in the analysis of variance. There were no significant differences between doses (100, 200 and 400 m g) for dose adjusted AUC ( F = 0.42, P = 0.6660), dose adjusted C max ( F = 0.08, P = 0.9206) and Tmax ( F = 0.94, P = 0.4107). Thus, these parameters showed dose proportionality. The differences (400-100 m g) in dose adjusted AUC from the three-period crossover analysis was -0.016 min·ng/ ml ( t = 0.71, P = 0.8718). Interindividual variability in systemic exposure to fentanyl was fairly small (25-40%), which may be related to a good in vivo biopharmaceutical performance of the sublingual tablet, and a relatively small fraction of the dose being swallowed. The first detectable plasma concentration of fentanyl was observed between 8 and 11 min after administration. t max increased from 39.7 ± 17.4 to 48.7 ± 26.3 and 56.7 ± 24.6 min for the 100, 200 and 400 m g doses, respectively. Adverse events were few and did not increase with increasing dose.B. Lennernäs et al. 25059 :2 Br J Clin Pharmacol ConclusionWith this rapidly dissolving fentanyl formulation, the first detectable plasma concentration of fentanyl was observed at 8-11 min after administration. The pharmacokinetics of the drug showed dose proportionately. This formulation of fentanyl seemed to be well tolerated by the patients.

Sahlgrenska Academy University of Gothenburg, Gothenburg, Sweden Abstract Once bone metastasized and androgen independent, prostate cancer is often associated with skeletal morbidity and disability. New treatment modalities that can palliate symptoms from the skeleton and inhibit further progression are warranted. In this study, the antitumoral effects following treatment with a combination of docetaxel and the new generation bisphosphonate, zoledronic acid, were investigated on two hormone-refractory prostate cancer cell lines: PC3 and DU145. The prostate cancer cells were treated with increasing concentrations of zoledronic acid in the absence or presence of docetaxel. Toxicity was measured using fluorometric microculture cytotoxic assay technique. A concentration of 25 mM, zoledronic acid reduced the viable cell number to 68% and 98% for PC3 and DU145 cells respectively. Docetaxel, on the other hand, at a concentration of 0.1 ng/ml, had no effect on the viability. However, a combination of zoledronic acid and docetaxel reduced the cell number to 60% and 81% respectively. Furthermore, zoledronic acid in the concentration range 12.5 mM Á/50 mM enhanced the antitumoral effects of docetaxel (0.01 Á/1 ng/ml) in an additive and/or synergistic manner for both cell lines. These data support the hypothesis that zoledronic acid, in addition to having bone resorption inhibiting properties, also exhibits anti-tumoral effects. It also appears that combined treatment with docetaxel causes additive and/or synergistic cytostatic effects on prostate cancer cells.