This article reports the clinical investigation of a probe drug cocktail containing substrates of key drug transporters. Single oral doses of 0.25 mg digoxin (P‐gp), 5 mg furosemide (OAT1 and OAT3), 500 mg metformin (OCT2, MATE1, and MATE2‐K), and 10 mg rosuvastatin (OATP1B1, OATP1B3, and BCRP) were administered separately or as a cocktail in a randomized six‐period crossover trial in 24 healthy male volunteers. As a cocktail, relative bioavailabilities of digoxin and metformin and furosemide AUC0‐tz were similar to separate dosing. However, when administered as a cocktail the Cmax of furosemide was 19.1% lower and the Cmax and AUC0‐tz of rosuvastatin were 38.6% and 43.4% higher, respectively. In addition, the effects of increased doses of metformin or furosemide on the cocktail were investigated in 11 and 12 subjects, respectively. The cocktail explored in this trial has the potential to be used for the in vivo screening of transporter‐mediated drug–drug interactions. © 2016 American Society for Clinical Pharmacology and Therapeutics

Background Monocytes and macrophages play a major role in the pathogenesis of rheumatoid arthritis (RA). The chemokine receptor CCR1 regulates migration of these cells to synovial tissue and the bone. It is expected that sustained full antagonism of CCR1 will block trafficking of monocytes to the site of inflammation and will block the upregulation of cytokines, adhesion molecules and MMPs to slow the progression of joint damage in RA. Objectives This clinical study investigated safety, tolerability, pharmacokinetics and pharmacodynamics of the novel selective CCR1 antagonist BI 638683. Methods In a randomised, blinded, placebo-controlled trial, single rising doses from 1 to 700 mg BI 638683 or placebo were administered to 63 young healthy male volunteers (mean age 32 ± 9 years; mean BMI was 24.7 ± 2.4 kg/m2). Subjects were randomised in a 6:2 ratio to active or placebo per group. Two distinct mechanistic blood-based biomarker assays were used to establish a PK/PD relationship: 1. inhibition of MIP1α-induced CCR1 receptor internalization (RI) and 2. inhibition of RANTES-induced CCR1 dependent gene expression of CCL2, CLEC5A, RAB7B and PPARG Results All doses of BI 638683 were well tolerated. There were no serious adverse events (AE) and no AEs of severe intensity. There was no dose-relationship of AEs and no difference in the number or category of reported AEs in subjects treated with BI 638683 (7/47; 14.9%) compared to those treated with placebo (3/16; 18.8%). The most frequent AEs were GI disorders which were reported in 5/47 (10.6%) subjects treated with BI 638683 and 2/16 (12.5%) subjects treated with placebo. Only one event of nausea in the 700g mg dose group was rated as drug related. Plasma exposure of BI 638683 increased in a near dose-linear fashion, with a terminal t½ of 5-15 h. Two hours after dosing (the pharmacokinetic tmax), a dose of 150 mg BI 638683 inhibited RI by approximately 90%. The percentage of inhibition was directly related to the dose of BI 638683. At the 700 mg dose, an 83% inhibition of RI was measured at 24 h after dosing. Maximal inhibition of mRNA expression of the 4 CCR1 dependent marker genes was reached with a dose of 75 mg BI 638683 at the tmax. 24 h after dosing, ≥90% mean inhibition was still maintained for CCL2 and PPARG mRNAs by doses of 300 mg and higher, and for RAB7B mRNA by doses of 500 mg and higher. For CLEC5A, inhibition of 84% and 91% was achieved for the 500 and 700 mg dose, respectively. Conclusions Treatment with BI 636683 was well tolerated. The biomarker assays indicated substantial inhibition and demonstrated proof of mechanism for BI 638683 as a CCR1 inhibitor in early stage of clinical development, and the PK/PD data using these biomarkers can be used to determine appropriate dosing for this compound. Disclosure of Interest : P. Baum Employee of: Boehringer-Ingelheim, C. Schoelch Employee of: Boehringer-Ingelheim, H. Zimdahl-Gelling Employee of: Boehringer-Ingelheim, M. Brown Employee of: Boehringer-Ingelheim, D. Webb Employee of: Boehringer-Ingelheim, S. Padula Employee of: Boehringer-Ingelheim, J. Hilbert Employee of: Boehringer-Ingelheim, T. Giessmann Employee of: Boehringer-Ingelheim, J. Steffgen Employee of: Boehringer-Ingelheim DOI 10.1136/annrheumdis-2014-eular.2352

The most frequent side effect associated with long term anticoagulant and antiplatelet therapy is bleeding. It has been attempted with different methods to assess blood loss in healthy volunteers (HV). The feasibility of two alternative methods for the assessment of bleeding due to anticoagulation

AIMS To evaluate whether simvastatin influences (i) the intestinal expression of P-glycoprotein (P-gp) and MRP2, and (ii) the disposition of the beta(1)-selective blocker talinolol, a substrate of these transporter proteins. METHODS The disposition of talinolol after intravenous (30 mg) and single or repeated oral administration (100 mg daily) was monitored before and after chronic treatment with simvastatin (40 mg daily) in 18 healthy subjects (10 males, eight females, body mass index 19.0-27.0 kg m(-2)) genotyped for ABCB1, ABCC2 and SLCO1B1 polymorphisms. The steady-state pharmacokinetics of simvastatin was evaluated before and after repeated oral talinolol administration. The duodenal expression of ABCB1 and ABCC2 mRNA before and after simvastatin treatment was quantified using real-time reverse transcriptase-polymerase chain reaction (TaqMan. RESULTS Simvastatin did not influence the expression of duodenal ABCB1 and ABCC2. There was no significant pharmacokinetic interaction between simvastatin and talinolol. Duodenal ABCB1 mRNA content was significantly correlated with the AUC(0-infinity) (r = 0.627, P = 0.039) and C(max) (r = 0.718, P = 0.013) of oral talinolol. The ABCB1 and ABCC2 gene polymorphisms did not influence simvastatin and talinolol disposition. The half-life of the latter was significantly shorter in the nine carriers with a SLCO1B1*1b allele compared with the seven subjects with the wild-type SLCO1B1*1a/*1a genotype (12.2 +/- 1.6 h vs. 14.5 +/- 1.4 h, P = 0.01). CONCLUSIONS Simvastatin does not influence the intestinal expression of P-gp and MRP2 in man. There was no pharmacokinetic interaction between talinolol and simvastatin during their chronic co-administration to healthy subjects.

BACKGROUND AND AIMS:Ezetimibe is an inhibitor of the cholesterol uptake transporter Niemann-Pick C1-like protein (NPC1L1). Target concentrations can be influenced by intestinal uridine diphosphate-glucuronosyltransferases (UGTs) and the efflux transporters P-glycoprotein (P-gp) (ABCB1) and multidrug resistance associated protein 2 (MRP2) (ABCC2). This study evaluates the contribution of these factors to the disposition and cholesterol-lowering effect of ezetimibe before and after induction of UGT1A1, P-gp, and MRP2 with rifampin (INN, rifampicin). METHODS:Serum concentrations of ezetimibe, as well as its glucuronide, and the plant sterols campesterol and sitosterol (surrogate for cholesterol absorption) were studied in 12 healthy subjects before and after rifampin comedication. In parallel, duodenal expression of UGT1A1, P-gp, MRP2, and NPC1L1 was quantified by use of real-time reverse transcriptase-polymerase chain reaction and quantitative immunohistochemical evaluation. The affinity of ezetimibe and its glucuronide to P-gp and MRP2 was assessed in P-gp- overexpressing Madin-Darby canine kidney II cells and P-gp-containing or MRP2-containing inside-out vesicles. RESULTS:Up-regulation of intestinal P-gp, MRP2, and UGT1A1 (but not of NPC1L1) by rifampin was associated with markedly decreased areas under the curve of ezetimibe and its glucuronide (116 +/- 78.1 ng.h/mL versus 49.9 +/- 31.0 ng.h/mL and 635 +/- 302 ng.h/mL versus 225 +/- 86.4 ng.h/mL, respectively; both P = .002) and increased intestinal clearances (2400 +/- 1560 mL/min versus 5500 +/- 4610 mL/min [P = .003] and 76.6 +/- 113 mL/min versus 316 +/- 457 mL/min [P = .010], respectively) and nearly abolished sterol-lowering effects. Intestinal expression of UGT1A1, ABCB1, and ABCC2 was inversely correlated with the effects of ezetimibe on plant sterol serum concentrations. Parallel in vitro studies confirmed that ezetimibe glucuronide is a high-affinity substrate of MRP2 and has a low affinity to P-gp whereas ezetimibe interacts with P-gp and MRP2. CONCLUSIONS:The disposition and sterol-lowering effects of ezetimibe are modified by metabolic degradation of the drug via intestinal UGT1A1 and either intestinal or hepatic secretion (or both) via P-gp and MRP2.

OBJECTIVE:Roflumilast is an oral, once-daily phosphodiesterase 4 inhibitor under investigation for the treatment of chronic obstructive pulmonary disease and asthma. In clinical practice, the drug is likely to be co-administered with inhaled bronchodilating beta2-adrenoceptor agonists. Therefore, this study investigated the pharmacokinetic characteristics of roflumilast and its pharmacodynamically active metabolite roflumilast N-oxide when co-administered with orally inhaled salbutamol in healthy subjects.METHODS:In this open, randomized clinical study, 12 healthy male subjects received repeated doses of oral roflumilast 500 microg once daily, orally inhaled salbutamol 200 microg 3 times daily, and a combination of both drugs over 7 days according to a 3-period, changeover design with 14 days washout between treatments.RESULTS:Co-administration of roflumilast and salbutamol did not markedly change roflumilast or roflumilast N-oxide disposition. Point estimates (90% confidence intervals) of area under the curve from 0-24 h (AUC 0-24) and maximum plasma concentration in steady state (Cmax,ss) for roflumilast with salbutamol versus roflumilast alone were 1.05 (0.94, 1.17) and 0.97 (0.84, 1.10); the respective point estimates (90% confidence intervals) for AUC 0-24 and Cmax,ss of roflumilast N-oxide were 0.98 (0.91, 1.06) and 0.98 (0.92, 1.03). Roflumilast co-administration did not alter the pharmacokinetics of steady state salbutamol. The respective point estimates (90% confidence intervals) for AUC 0-6 and Cmax,ss of salbutamol with roflumilast versus salbutamol alone were 1.10 (0.99, 1.21), 1.08 (0.91, 1.28). The combination of both drugs was well tolerated.CONCLUSION:There were no relevant pharmacokinetic interactions between roflumilast and salbutamol at therapeutically effective doses.

UNLABELLED There is ample evidence that non-cholinergic protein kinase C (PKC) mediated signal transduction pathways are involved into regulation of bladder smooth muscle contractions. To evaluate whether the anticholinergic and calcium modulating drug propiverine exerts intracellular effects by inhibition of the PKC, male inbred LEW 1A rats were pretreated with 0.6, 2, 6 and 60 mg/kg body weight for 5 days. Furthermore, competition assays with partially purified PKC were performed with propiverine in vitro. The activities of the membrane-bound and soluble PKC were assessed by 32P enrichment of lysine-rich histone. RESULTS The active, membrane-bound PKC decreased by about 60% accompanied by increase of the soluble form after propiverine in doses above 0.6 mg/kg. 100 nM of the drug inhibited the PKC also in vitro whereas the propiverine metabolites M5 and M6 and atropine were without any effect. CONCLUSIONS Propiverine was identified to be an inhibitor of the protein kinase C. Its contribution to the noncholinergic control of hyperactive detrusor smooth muscle cells needs further investigation.

AIM:The gastrointestinal transit of sequentially administered capsules was investigated in relation to the availability of fluid along the intestinal lumen by magnetic resonance imaging.METHODS:Water-sensitive magnetic resonance imaging was performed on 12 healthy subjects during fasting and 1 h after a meal. Specifiable non-disintegrating capsules were administered at 7, 4 and 1 h prior to imaging.RESULTS:While food intake reduced the mean fluid volumes in the small intestine (105 +/- 72 mL vs. 54 +/- 41 mL, P < 0.01) it had no significant effect on the mean fluid volumes in the colon (13 +/- 12 mL vs. 18 +/- 26 mL). The mean number of separated fluid pockets increased in both organs after meal (small intestine: 4 vs. 6, P < 0.05; large intestine: 4 vs. 6, P < 0.05). The distribution of capsules between the small and large intestine was strongly influenced by food (colon: 3 vs. 17 capsules, P < 0.01).CONCLUSIONS:The results show that fluid is not homogeneously distributed along the gut, which likely contributes to the individual variability of drug absorption. Furthermore, transport of fluid and solids through the ileocaecal valve is obviously initiated by a meal-induced gastro-ileocaecal reflex.

Background Clinical trials have indicated that the combined β‐ and α‐adrenergic receptor blocker carvedilol improves the survival rate in patients with advanced chronic heart failure. The objective of our study was the identification and quantification of factors that modulate steady‐state serum concentrations of carvedilol and its enantiomers and that may influence therapeutic efficacy and safety. Methods The influence of genetic variants of cytochrome P450 (CYP) 2D6 and CYP2C9 and of transporter proteins (P‐glycoprotein, multidrug resistance protein 2 [MRP2]) on the disposition of carvedilol and its enantiomers after intravenous (5 mg) and long‐term oral administration (25 mg for 7 days) was assessed in 12 healthy subjects. The intestinal expression of P‐glycoprotein and MRP2 was analyzed by quantitative real‐time polymerase chain reaction and immunohistochemical techniques. Results The area under the serum concentration–time curve (AUC) values of carvedilol were significantly ( P < .05) increased in 6 subjects with CYP2D6 deficiency, with effects being more pronounced for R (+)‐carvedilol (230 ± 72.6 ng · h/mL versus 93.9 ± 64.6 ng · h/mL in extensive metabolizers) than for S (−)‐carvedilol (62.9 ± 21.1 ng · h/mL versus 32.7 ± 14.5 ng · h/mL). The AUC and fecal excretion of intravenous carvedilol were correlated with the intestinal expression of MDR1 messenger ribonucleic acid (mRNA) ( r = −0.67, P = .001; r = 0.83, P = .002) and MRP2 mRNA ( r = −0.74, P < .001; r = 0.70, P = .025). Furthermore, we measured the disposition of long‐term oral carvedilol after comedication of the pregnane X receptor ligand rifampin (INN, rifampicin) (600 mg, 9 days), which up‐regulates both P‐glycoprotein and MRP2 but not CYP2D6. Rifampin decreased the AUC of carvedilol to an extent independent of the CYP2D6 genotype (poor metabolizers, 341 ± 147 ng · h/mL versus 126 ± 41.7 ng · h/mL; extensive metabolizers, 173 ± 102 ng · h/mL versus 74 ± 41.4 ng · h/mL; both P < .05). The AUC was significantly correlated with intestinal expression of MDR1 mRNA ( r = −0.671, P = .001) and MRP2 mRNA ( r = −0.595, P < .006). Conclusions Variable plasma concentrations of carvedilol during long‐term administration are predicted by CYP2D6 genotype and intestinal expression of P‐glycoprotein and MRP2. Clinical Pharmacology & Therapeutics (2004) 75 , 213–222; doi: 10.1016/j.clpt.2003.10.004

Problem: There is evidence (NEJM 1999;340:424) that replacement therapy of hypothyroidism with levothyroxine (T4) combined with triiodothyronine (T3) may improve the wellbeing of patients. However, the study is still subject of controversial debate.

Summaryobjectives There is evidence from recent controlled clinical studies that replacement therapy of hypothyroidism with T4 in combination with a small amount of T3 may improve the well‐being of the patients. As the issue is still the subject of controversial discussion, our study was assigned to confirm the superiority of a physiological combination of thyroid hormones (absorbed molar ratio 14 : 1) over T4 alone with regard to mood states and cognitive functioning.design and patients After a run‐in period with the T4 study medication for 4 weeks, a controlled, randomized, double‐blind, two‐period (each 12 weeks), cross‐over study without washout between the treatment periods was performed in 23 hypothyroid patients (three males, 20 females, age 23–69 years, 21 subjects after surgery/radioiodine, two with autoimmune thyroiditis) to compare the effects of the previous individual T4 dose (100–175 µg) with a treatment in which 5% of the respective T4 dose was substituted by T3.measurements Standard hormonal characteristics and standardized psychological tests to quantify mood and cognitive performance were measured after the run‐in period and at the end of each treatment period. In 12 subjects, the concentration–time profiles of fT3 and fT4 were compared after the last administration of the respective study medication. TSH, fT3 and fT4 were measured with immunological assays.clinical results Replacement therapy with T4 and T4/T3 was not different in all steady‐state hormonal, metabolic and cardiovascular characteristics except for TSH, which was more suppressed after T4/T3. The efficacy of replacement therapy with the T4/T3 combination was not different from the T4 monotherapy with regard to all psychological test scores describing mood and cognitive functioning of the patients. Mood was even significantly impaired by the T4/T3 combination in eight subjects, with TSH < 0·02 mU/l, compared to patients with normal TSH (Beck Depression Inventory: 8·25 ± 5·01 vs. 4·07 ± 5·60, P = 0·026).pharmacokinetic results The area under the concentration–time curve (AUC0−8h) of fT3 was significantly higher after T4/T3 compared to the T4 monotherapy (42·8 ± 9·03 pmol × h/l vs. 36·3 ± 8·50 pmol × h/l, P < 0·05) and was significantly correlated to serum TSH (rs = −0·609, P < 0·05). After T4/T3, patients with a history of Graves’ disease or autoimmune thyroiditis had significantly higher serum trough levels of fT3 whereas the fT4 concentrations were significantly lower in patients with a nonautoimmune background.conclusion Replacement therapy of hypothyroidism with T4 plus T3 does not improve mood and cognitive performance compared to the standard T4 monotherapy. There is even a higher risk of signs of subclinical hyperthyroidism associated with impaired well‐being of the patients, which is clearly caused by significant fluctuations in the steady‐state fT3 serum concentrations.