Sorafenib is a novel, small-molecule anticancer compound that inhibits tumor cell proliferation by targeting Raf in the Raf/MEK/ERK signalling pathway, and inhibits angiogenesis by targeting tyrosine kinases such as vascular-endothelial growth factor receptor (VEGFR-2 and VEGFR-3) and platelet-derived growth factor receptor (PDGFR). In vitro microsomal data indicate that sorafenib is metabolized by two pathways: phase I oxidation mediated by cytochrome P450 (CYP) 3A4; and phase II conjugation mediated by UGT1A9. Approximately 50% of an orally administered dose is recovered as unchanged drug in the feces, due to either biliary excretion or lack of absorption. The aim of this study was to evaluate the effect of CYP3A inhibition by ketoconazole on sorafenib pharmacokinetics. This was an open-label, non-randomized, 2-period, one-way crossover study in sixteen healthy male subjects. A single 50 mg dose of sorafenib was administered alone (period 1) and in combination with ketoconazole 400 mg once daily (period 2) (ketoconazole was given for 7 days, and a single 50 mg sorafenib dose was administered concomitantly on day 4). No clinically relevant change in pharmacokinetics of sorafenib and no clinically relevant adverse events or laboratory abnormalities were observed in this study upon co-administration of the two drugs. Plasma concentrations of the main CYP3A4 generated metabolite, sorafenib N-oxide, decreased considerably upon ketoconazole co-administration. This effect is in accordance with the in vitro finding that CYP3A4 is the primary enzyme for sorafenib N-oxide formation. Further, these data indicate that blocking sorafenib metabolism by the CYP3A4 pathway will not lead to an increase in sorafenib exposure. This is consistent with data from a clinical mass-balance study that showed 15% of the administered dose was eliminated by glucuronidation, compared to less than 5% eliminated as oxidative metabolites. Since there was no increase in sorafenib exposure following concomitant administration of the highly potent CYP3A4 inhibitor ketoconazole with low dose sorafenib, it is postulated that higher therapeutic doses of sorafenib may be safely co-administered with ketoconazole, as well as with other inhibitors of CYP3A.

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Vardenafil 10 mg did not impair the ability of patients with stable CAD to exercise at levels equivalent or greater than that attained during sexual intercourse (average of 2.5 to 3.3 METS).

The effects of food on the pharmacokinetics of vardenafil were examined in 25 healthy adult males. Single-dose vardenafil 20 mg was administered in a randomized four-way crossover design after an overnight fast (at 8 a.m.), after consumption of a high-fat breakfast (at 8 a.m.), on an empty stomach (at 6 p.m.), and after a typical moderate-fat evening meal (at 6 p.m.). Serial blood samples were analyzed for vardenafil and metabolite (M1) levels. When administered after an overnight fast and after a high-fat breakfast, vardenafil geometric mean Cmax was 17.14 and 14.0 micrograms/L, respectively, and AUC was 66.78 and 67.09 micrograms./h/L, respectively; the median tmax was 1 hour under fasting conditions and 2 hours with consumption of high-fat breakfast. When administered in the evening on an empty stomach and after a moderate-fat meal, vardenafil geometric mean Cmax was 14.22 and 13.04 micrograms/L, respectively, and AUC was 51.97 and 59.12 micrograms.h/L, respectively. The median tmax was 1 hour after fasting or a moderate-fat meal in the evening. All treatments were well tolerated. Thus, while a high-fat meal may alter Cmax slightly and delay the absorption up to 1 hour, a moderate-fat meal has no clinically relevant effect on vardenafil pharmacokinetics. Dosage changes are not warranted based on the wide therapeutic index and the efficacy observed with vardenafil in Phase III studies that were not restricted with respect to food.

The effect of streptozotocin-induced diabetes on the beta-adrenergic receptor-coupled adenylate cyclase was studied in rat heart particulate fractions. Streptozotocin treatment decreased the number of myocardial beta-adrenergic receptors by 34% with no change in the apparent affinity of these receptors for [3H]dihydroalprenolol. The maximal isoproterenol-activated accumulation of cAMP in streptozotocin-treated rat hearts was decreased by only 10%. Insulin administration to streptozotocin-treated rats increased the number of myocardial beta-adrenergic receptors to near or above control levels. Administration of L-T4 to streptozotocin-treated rats had the same effect. Total T4, free T4, and total T3 levels were all significantly decreased in the diabetic animals. Administration of insulin to streptozotocin-treated rats increased the serum thyroid hormone levels toward or above the levels found in control animals. Streptozotocin-induced diabetes had no significant effect on cardiac beta-adrenergic receptor number in thyroidectomized rats. Insulin did not elevate cardiac beta-adrenergic receptor number in thyroidectomized diabetic rats. The decrease in the number of myocardial beta-adrenergic receptors occurring in diabetes mellitus is probably mediated through thyroid hormones.

PurposeTo characterize the cardiovascular profile of sorafenib, a multitargeted kinase inhibitor, in patients with advanced cancer.MethodsFifty-three patients with advanced cancer received oral sorafenib 400 mg bid in continuous 28-day cycles in this open-label study. Left ventricular ejection fraction (LVEF) was evaluated using multigated acquisition scanning at baseline and after 2 and 4 cycles of sorafenib. QT/QTc interval on the electrocardiograph (ECG) was measured in triplicate with a Holter 12-lead ECG at baseline and after 1 cycle of sorafenib. Heart rate (HR) and blood pressure (BP) were obtained in duplicate at baseline and after 1 and 4 cycles of sorafenib. Plasma pharmacokinetic data were obtained for sorafenib and its 3 main metabolites after 1 and 4 cycles of sorafenib.ResultsLVEF (SD) mean change from baseline was −0.8 (±8.6) LVEF(%) after 2 cycles (n = 31) and −1.2 (±7.8) LVEF(%) after 4 cycles of sorafenib (n = 24). The QT/QTc mean changes from baseline observed at maximum sorafenib concentrations (tmax) after 1 cycle (n = 31) were small (QTcB: 4.2 ms; QTcF: 9.0 ms). Mean changes observed after 1 cycle in BP (n = 31) and HR (n = 30) at maximum sorafenib concentrations (tmax) were moderate (up to 11.7 mm Hg and −6.6 bpm, respectively). No correlation was found between the AUC and Cmax of sorafenib and its main metabolites and any cardiovascular parameters.ConclusionsThe effects of sorafenib on changes in QT/QTc interval on the ECG, LVEF, BP, and HR were modest and unlikely to be of clinical significance in the setting of advanced cancer treatment.

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To investigate the value of anorexiant medications as an adjunct to other forms of weight control therapy, we studied 121 people in a 34-week, double-blind clinical trial of 60 mg extended-release fenfluramine plus 15 mg phentermine resin versus placebo added to behavior modification, caloric restriction, and exercise. Participants weighed 130% to 180% (154% +/- 1.2%, mean +/- SEM) of ideal body weight (1983 Metropolitan Life tables) and were in good health. By week 34, participants receiving active medication lost an average of 14.2 +/- 0.9 kg, or 15.9% +/- 0.9% of initial weight (n = 58), versus a loss of 4.6 +/- 0.8 kg or 4.9% +/- 0.9% of initial weight by subjects taking placebo (n = 54; p less than 0.001). On visual analog scales, participants rated fenfluramine plus phentermine as more helpful than placebo (50.3 +/- 0.5 versus 20.3 +/- 0.3) and not bothersome (fenfluramine plus phentermine, 17.4 +/- 0.3 versus 13.5 +/- 0.2). Blood pressure decreased and pulse remained unchanged in both groups. Dry mouth was the most common adverse effect in subjects receiving fenfluramine plus phentermine; all adverse effects decreased after 4 weeks. Only nine participants left the study in the first 34 weeks. Two subjects from each group left the study as a result of adverse effects. Overall, fenfluramine plus phentermine used in conjunction with behavior modification, caloric restriction, and exercise aided weight loss and continued to be efficacious for 34 weeks.