Effect of grapefruit juice and food on the pharmacokinetics of pirfenidone in healthy Chinese volunteers: a diet–drug interaction study

1.?Ingestion of grapefruit juice and food could be factors affecting the pharmacokinetics of pirfenidone, a promising drug for treatment of idiopathic pulmonary fibrosis.

2.?A randomized, open-label, three-period crossover study was carried out in 12 healthy Chinese male volunteers who were randomized to one of the three treatments: pirfenidone tablets (0.4?g) were orally administered to fasted or fed subjects, or with grapefruit juice. The washout period was 7 d.

3.?Significantly reduced maximum plasma concentration (C_max, 5.0 5?±?1.39 versus 10.9 0?±?2.94?mg·L^{? 1}), modestly affected area-under-the-plasma concentration–time curve (AUC) from time zero to 12?h post dosing (AUC_0–12?h, 21.8 9?±?6.47 versus 26.1 6?±?7.32?mg·h·L^{? 1}) and delayed time to reach C_max (T_max) were observed in fed group compared with fasted group. Similar effects on C_max (5.8 2?±?1.23 versus 10.9 0?±?2.94?mg·L^{? 1}) and AUC_0–12?h (modest but not statistically significant, 24.4 4?±?7.40 versus 26.1 6?±?7.32?mg·h·L^{? 1}) were observed for grapefruit juice compared to fasted subjects.

4.?Co-administration of pirfenidone with grapefruit juice resulted in modestly reduced overall oral absorption and significantly reduced peak concentrations compared to fasting, which was similar to effect of food ingestion. No adverse events were observed in the study, but relatively dramatic reduction of peak concentrations should raise concerns for clinical efficacy and safety.     

Drug–drug interaction of rabeprazole and clopidogrel in healthy Chinese volunteers

Purpose

This study was aimed to determine the impact of rabeprazole (RBRZ) on the antiplatelet efficacy of clopidogrel (CPG) in healthy Chinese volunteers, and further to predict the effect of CYP2C19 genetic polymorphism on the efficacy of rabeprazole and clopidogrel.

Methods

The open-label, two period cross-over study was conducted in 20 healthy Chinese subjects with different CYP2C19 genotypes receiving clopidogrel, rabeprazole or the two drugs, respectively. All the volunteers were divided into two groups, poor metabolizers (PMs) and extensive metabolizers (EMs), depending on CYP2C19 genotypes. Blood samples were collected at baseline and at 0.5, 1, 2, 3, 4, 6, 8, 10, and 12 h after administration. The plasma concentrations of rabeprazole and clopidogrel were analyzed by LC-MS/MS and ADP-induced platelet aggregation was detected by the optical turbidimetric method.

Results

There were no significant differences in the mean plasma concentration–time curves of clopidogrel (CPG), the inactive metabolite clopidogrel carboxylic acid (CPG-CA), the active metabolite clopidogrel-MP-Derivative (MP-AM), and rabeprazole (RBRZ) according to the co-administration of CPG and RBRZ. There were no major changes in the pharmacokinetics of CPG and RBRZ. The maximal ADP-induced platelet aggregation (2 μmol/L) was decreased in EMs compared with PMs.

Conclusion

Co-administration of rabeprazol and clopidogrel did not affect the antiplatelet efficacy of clopidogrel. The CYP2C19 genetic polymorphism may impact the efficacy of clopidogrel.     

Safety, tolerability and pharmacokinetic study of recombinant human parathyroid hormone in healthy male Chinese subjects

AIM： To determine the safety, tolerability and pharmacokinetic parameters of a new drug recombinant human parathyroid hormone [ rhPTH （1-84）] in healthy male Chinese subjects. METHODS： domly divided Thirty-six healthy male volunteers were rangroups received into 3 groups. The volunteers in these single subcutaneous injection of rhPTH （ 1-84） in a dosage of 1, 2 and 4 μg/kg respectively. Blood samples were obtained before and after administration within 24 hours. The rhPTH concentrations in sennn were determined by enzyme linked immunosorbent assay （ELISA）. The pharmacokinetic parameters determined with use of standard noncompartmental analysis were the maximum serum concentration （ Cmax ）, the time to attain that concentration （ tmax ）, and the area under the serum concentration-time curve up to 24 hours（ AUC0-24 ） and up to infinity （AUC0-∞）. Dose proportionality of pharmacokinetic parameters （AUC, Cmax of every volunteer of each dosage and A UC was computed from log transformed data） and was examined by mean of analysis of variance （ANOVA） using SPSS software package. In the study, subjects＇ symptoms, objective signs, and vital signs, including blood pressure, heart rate, respiratory rate and body temperature, were checked and 12-lead electrocardiography was recorded before and after drug administration within 24 hours. Routine laboratory tests, including hematology, blood biochemistry, serum electrolyte, and urinalysis, were performed before and after drug administration within at 24 hours.[第一段]     

Antimicrobial use and drug–drug interactions among nursing home residents in Singapore: a multicentre prevalence study

Background With the Ministry of Health’s projected increase in nursing home beds and optimization of antimicrobial use in health care settings, it is therefore timely to consider baseline prevalence and patterns of antimicrobial use at nursing homes in Singapore as well as to evaluate the prevalence of potential clinically significant drug–drug interactions involving antimicrobials. Objective The primary objective was to determine the prevalence and patterns of antimicrobial use at nursing homes in Singapore. The secondary objective was to evaluate the prevalence of potential clinically significant drug–drug interactions involving antimicrobials. Setting Four nursing homes in Singapore. Method A retrospective cross-sectional study was conducted among nursing home residents. The antimicrobial prevalence, defined daily doses, days of therapy, and potential drug–drug interactions were determined using data from archived resident medication prescribing and administration records. Main outcome measure Prevalence and patterns of antimicrobial use, drug–drug interactions involving antimicrobials. Results Among 707 residents (mean age: 80.7?±?8.8 years, female: 57.1%), 10% used antimicrobials during the study month, with a 1-day point prevalence of 3%. The utilization rates of antimicrobials were 28.9 defined daily doses/1000 resident-days and 24.8 days of therapy/1000 resident-days. Potential drug–drug interactions involving antimicrobials were identified among 32 of the 70 (46%) residents who were prescribed antimicrobials. Of these, 26 (81%) residents had 43 potential clinically significant drug–drug interactions. Conclusions The prevalence and utilization rates of antimicrobial use in Singapore nursing homes appear to be low. Yet, potential clinically significant drug–drug interactions are prevalent.     

Retrospective use of PBPK modelling to understand a clinical drug–drug interaction between dextromethorphan and GSK1034702

1.?In a clinical trial, a strong drug–drug interaction (DDI) was observed between dextromethorphan (DM, the object or victim drug) and GSK1034702 (the precipitant or perpetrator drug), following single and repeat doses. This study determined the inhibition parameters of GSK1034702 in vitro and applied PBPK modelling approaches to simulate the clinical observations and provide mechanistic hypotheses to understand the DDI.

2.?In vitro assays were conducted to determine the inhibition parameters of human CYP2D6 by GSK1034702. PBPK models were populated with the in vitro parameters and DDI simulations conducted and compared to the observed data from a clinical study with DM and GSK1034702.

3.?GSK1034702 was a potent direct and metabolism-dependent inhibitor of human CYP2D6, with inhibition parameters of: IC_50?=_?1.6?μM, K_inact?=?3.7?h^?1 and K_I?=?0.8?μM. Incorporating these data into PBPK models predicted a DDI after repeat, but not single, 5?mg doses of GSK1034702.

4.?The DDI observed with repeat administration of GSK1034702 (5?mg) can be attributed to metabolism-dependent inhibition of CYP2D6. Further, in vitro data were generated and several potential mechanisms proposed to explain the interaction observed following a single dose of GSK1034702.     

Evaluation of drug–drug interaction between henagliflozin,a novel sodium-glucose co-transporter 2 inhibitor,and metformin in healthy Chinese males

1.?Henagliflozin is a novel sodium-glucose transporter 2 inhibitor and presents a complementary therapy to metformin for patients with T2DM due to its insulin-independent mechanism of action. This study evaluated the potential pharmacokinetic drug-drug interaction between henagliflozin and metformin in healthy Chinese male subjects.

2.?In open-label, single-center, single-arm, two-period, three-treatment self-control study, 12 subjects received 25?mg henagliflozin, 1000?mg metformin or the combination. Lack of PK interaction was defined as the ratio of geometric means and 90% confidence interval (CI) for combination: monotherapy being within the range of 0.80-1.25.

3.?Co-administration of henagliflozin with metformin had no effect on henagliflozin area under the plasma concentration-time curve (AUC_0–24) (GRM: 1.08; CI: 1.05, 1.10) and peak plasma concentration (C_max) (GRM: 0.99; CI: 0.92, 1.07). Reciprocally, co-administration of metformin with henagliflozin had no clinically significant on metformin AUC_0–24 (GRM: 1.09, CI: 1.02, 1.16) although there was an 11% increase in metformin C_max (GRM 1.12; CI 1.02, 1.23). All monotherapies and combination therapy were well tolerated.

4.?Henagliflozin can be co-administered with metformin without dose adjustment of either drug.     

Comparison of two endogenous biomarkers of CYP3A4 activity in a drug–drug interaction study between midostaurin and rifampicin

Purpose

Midostaurin, a multitargeted tyrosine kinase inhibitor, is primarily metabolized by CYP3A4. This midostaurin drug–drug interaction study assessed the dynamic response and clinical usefulness of urinary 6β-hydroxycortisol to cortisol ratio (6βCR) and plasma 4β-hydroxycholesterol (4βHC) for monitoring CYP3A4 activity in the presence or absence of rifampicin, a strong CYP3A4 inducer.

Methods

Forty healthy adults were randomized into groups for either placebo or treatment with rifampicin 600 mg QD for 14 days. All participants received midostaurin 50 mg on day 9. Midostaurin plasma pharmacokinetic parameters were assessed. Urinary 6βCR and plasma 4βHC levels were measured on days 1, 9, 11, and 15.

Results

Both markers remained stable over time in the control group and increased significantly in the rifampicin group. In the rifampicin group, the median increases (vs day 1) on days 9, 11, and 15 were 4.1-, 5.2-, and 4.7-fold, respectively, for 6βCR and 3.4-, 4.1-, and 4.7-fold, respectively, for 4βHC. Inter- and intrasubject variabilities in the control group were 45.6 % and 30.5 %, respectively, for 6βCR, and 33.8 % and 7.5 %, respectively, for 4βHC. Baseline midostaurin area under the concentration–time curve (AUC) correlated with 4βHC levels (ρ?=??0.72; P?=?.003), but not with 6βCR (ρ?=?0.0925; P?=?.6981).

Conclusions

Both 6βCR and 4βHC levels showed a good dynamic response range upon strong CYP3A4 induction with rifampicin. Because of lower inter- and intrasubject variability, 4βHC appeared more reliable and better predictive of CYP3A4 activity compared with 6βCR. The data from our study further support the clinical utility of these biomarkers.     

Research on the pharmacokinetics of single dose and multipledose of gemifloxacin in healthy Chinese male subjects

AIM： To investigate the pharmacokinetics and safety of gemifloxacin in healthy Chinese subjects and provide some theoretic bases for its reasonable application in clinic. METHODS： （1） 12 healthy Chinese male subjects were enrolled in this study with an open label, 3-period crossover oral single dosing pharmacokinetic study. The subjects sequentially took 3 doses of gemifloxacin （ 160, 320 and 480 mg） according to the randomization schedule. （2）20 subjects were chosen to participate in a randomized, double blind, multiple dosing pharmacokinetic study. The subjects were orally given 320 mg gemifloxacin or matching placebo once daily for 7 consecutive days. Clinical observation and laboratory test were performed during the study for the assessment of adverse events. The concentrations of gemifloxacin in serum and urine were determined by high performance liquid chromatogram （HPLC）. The pharmacokinetic parameters were analysed by 31797 analysis software. RESULTS： （1）The pharmacokinetic courses following single crossover oral dose of 160, 320 and 480 mg were all in accordance with the two-compartment model.[第一段]     

Potential protective effect of sunitinib after administration of diclofenac: biochemical and histopathological drug–drug interaction assessment in a mouse model

Sunitinib is a tyrosine kinase inhibitor for GIST and advanced renal cell carcinoma. Diclofenac is used in cancer pain management. Coadministration may mediate P450 toxicity. We evaluate their interaction, assessing biomarkers ALT, AST, BUN, creatinine, and histopathological changes in the liver, kidney, heart, brain, and spleen. ICR mice (male, n?=?6 per group/dose) were administered saline (group A) or 30 mg/kg diclofenac ip (group B), or sunitinib po at 25, 50, 80, 100, 140 mg/kg (group C) or combination of diclofenac (30 mg/kg, ip) and sunitinib (25, 50, 80, 100, 140 mg/kg po). Diclofenac was administered 15 min before sunitinib, mice were euthanized 4 h post-sunitinib dose, and biomarkers and tissue histopathology were assessed. AST was 92.2?±?8.0 U/L in group A and 159.7?±?14.6 U/L in group B (p?<?0.05); in group C, it the range was 105.1–152.6 U/L, and in group D, it was 156.0–209.5 U/L (p?<?0.05). ALT was 48.9?±?1.6 U/L (group A), 95.1?±?4.5 U/L (p?<?0.05) in group B, and 50.5–77.5 U/L in group C and 82.3–115.6 U/L after coadministration (p?<?0.05). Renal function biomarker BUN was 16.3?±?0.6 mg/dl (group A) and increased to 29.9?±?2.6 mg/dl in group B (p?<?0.05) and it the range was 19.1–33.3 mg/dl (p?<?0.05) and 26.9–40.8 mg/dl in groups C and D, respectively. Creatinine was 5.9 pmol/ml in group A; 6.2 pmol/ml in group B (p?<?0.01), and the range was 6.0–6.2 and 6.2–6.4 pmol/ml in groups C and D, respectively (p?<?0.05 for D). Histopathological assessment (vascular and inflammation damages) showed toxicity in group B (p?<?0.05) and mild toxicity in group C. Damage was significantly lesser in group D than group B (p?<?0.05). Spleen only showed toxicity after coadministration. These results suggest vascular and inflammation protective effects of sunitinib, not shown after biomarker analysis.     

Drug metabolism and liver disease: a drug–gene–environment interaction

Despite the central role of the liver in drug metabolism, surprisingly there is lack of certainty in anticipating the extent of modification of the clearance of a given drug in a given patient. The intent of this review is to provide a conceptual framework in considering the impact of liver disease on drug disposition and reciprocally the impact of drug disposition on liver disease. It is proposed that improved understanding of the situation is gained by considering the issue as a special example of a drug–gene–environment interaction. This requires an integration of knowledge of the drug’s properties, knowledge of the gene products involved in its metabolism, and knowledge of the pathophysiology of its disposition. This will enhance the level of predictability of drug disposition and toxicity for a drug of interest in an individual patient. It is our contention that advances in pharmacology, pharmacogenomics, and hepatology, together with concerted interests in the academic, regulatory, and pharmaceutical industry communities provide an ideal immediate environment to move from a qualitative reactive approach to quantitative proactive approach in individualizing patient therapy in liver disease.     

Clinical disposition,metabolism and in vitro drug–drug interaction properties of omadacycline

1.?Absorption, distribution, metabolism, transport and elimination properties of omadacycline, an aminomethylcycline antibiotic, were investigated in vitro and in a study in healthy male subjects.

2.?Omadacycline was metabolically stable in human liver microsomes and hepatocytes and did not inhibit or induce any of the nine cytochrome P450 or five transporters tested. Omadacycline was a substrate of P-glycoprotein, but not of the other transporters.

3.?Omadacycline metabolic stability was confirmed in six healthy male subjects who received a single 300?mg oral dose of [¹⁴C]-omadacycline (36.6 μCi). Absorption was rapid with peak radioactivity (～610 ngEq/mL) between 1–4?h in plasma or blood. The AUC_last of plasma radioactivity (only quantifiable to 8?h due to low radioactivity) was 3096 ngEq?h/mL and apparent terminal half-life was 11.1?h. Unchanged omadacycline reached peak plasma concentrations (～563?ng/mL) between 1–4?h. Apparent plasma half-life was 17.6?h with biphasic elimination. Plasma exposure (AUC_inf) averaged 9418?ng?h/mL, with high clearance (CL/F, 32.8?L/h) and volume of distribution (Vz/F 828?L). No plasma metabolites were observed.

4.?Radioactivity recovery of the administered dose in excreta was complete (>95%); renal and fecal elimination were 14.4% and 81.1%, respectively. No metabolites were observed in urine or feces, only the omadacycline C4-epimer.     

Biotransformation and in vitro assessment of metabolism-associated drug–drug interaction for CRx-102, a novel combination drug candidate

CRx-102 is an oral synergistic combination drug which contains the cardiovascular agent, dipyridamole (DP) and a very low dose of the glucocorticoid, prednisolone (PRED). CRx-102 works through a novel mechanism of action in which DP selectively amplifies the anti-inflammatory activity of PRED without replicating its side effects. CRx-102 is in clinical trials for the treatment of osteoarthritis. Here we delineate the in vitro metabolism and explore the potential for a drug–drug interaction between the active agents in CRx-102. Our study using human hepatocyte suspensions showed that both DP and PRED were metabolized by CYP3A4 isozymes, resulting in the formation of diverse arrays of both oxidative and oxidative-reduced metabolites. Within phase 1 biotransformation, CYP3A4 was one of the pathways responsible for the metabolism of PRED, while phase 2 biotransformation played a significant role in the metabolism of DP. Glucuronidation of DP was substantial and was catalyzed by many UGT members, specifically those in the UGT1A subfamily. Based on the tandem mass (MS/MS) product ion spectra (PIS) acquired, the major metabolites of both agents, namely, monooxygenated, mono-N-deethanolaminated, dehydrogenated and O-glucuronidated metabolites of DP and the monooxygenated (e.g., 6-hydroxyl), dehydrogenated (prednisone) and reduced (20-hydroxyl) metabolites of PRED, were identified and elucidated. The affinities for DP biotransformation, including CYP3A4-mediated oxidative pathways and UGT-mediated O-glucuronidation, appeared high (K_m < 10 μM), as compared with the modest affinities of PRED biotransformation catalyzed by CYP3A4 (K_m ∼ 40–170 μM). DP, but not PRED, exerted a minimal inhibitory effect on the drug-metabolizing CYP isoforms, including CYP3A4, which was determined using a panel of CYP isoform-preferred substrate activities in pooled human liver microsomal (HLM) preparations and microsomal preparations containing the recombinant enzymes (K_i ∼ 2–12 μM). Using the DP maximal plasma concentration (C_max) observed in the clinic and a predictive mathematical model for metabolism-associated drug–drug interaction (DDI), we have demonstrated that there is little likelihood of a pharmacokinetic interaction between the two active agents in CRx-102.     

The importance of drug–drug interactions as a cause of adverse drug reactions: a pharmacovigilance study of serotoninergic reuptake inhibitors in France

Purpose  

To quantify the importance of drug–drug interactions (DDIs) in the occurrence of adverse drug reactions (ADRs) reported with serotoninergic reuptake inhibitors in a pharmacovigilance database.     

Use of an adaptive study design in single ascending-dose pharmacokinetics of A0001 (α-tocopherylquinone) in healthy male subjects

A0001 (α-tocopherylquinone) is a potent antioxidant currently in development for the treatment of symptoms associated with inherited mitochondrial disorders. A0001 pharmacokinetics were studied in a single-blind, adaptive design study following a single daily oral dose of placebo (n = 2) or ascending doses of A0001 (n = 8) at 0.25 and 0.5 g under a fasted state or a 0.5- to 6-g dose with a high-fat meal. Dose escalation was based on safety assessment, and proceeding dose levels were selected based on interim pharmacokinetic analyses. A0001 plasma concentration-time profiles were similar across doses, reaching peak concentration within 4 to 6 hours, with concentrations returning to baseline within 24 hours. Exposure was highly dependent on food and dosing frequency. Exposure was nearly 60-fold higher with food but increased subproportionally above 1-g dose; however, the nonproportionality was offset by administering A0001 in divided doses (0.735 g, 3 times per day). The potential for an A0001:vitamin E interaction was also explored, as vitamin E use is prevalent in this patient population, and suggested that a clinically significant pharmacokinetic interaction is not likely. A0001 was well tolerated with no serious adverse events or dose-limiting toxicities. These findings suggest that A0001 has a favorable pharmacokinetic profile when administered orally with food.     

Clinical study of lamotrigine and valproic acid in patients with epilepsy: using a drug interaction to advantage?

Lamotrigine (LTG) is one of the newer antiepileptic drugs which has been shown to have a spectrum of drug interactions (including with other epilepsy drugs) that can have a pronounced effect on LTG kinetics. The present study examined the LTG metabolic inhibition dose-response relationship with valproic acid (VPA) in eight patients with epilepsy with a view to using this to benefit the patient. This could benefit the patient not only by attaining higher plasma LTG concentrations with "standard" dosages of LTG, but also possibly by achieving better seizure control through providing a less variable peak-to-trough fluctuation in LTG concentrations as a result of extending the half-life of LTG. The dosages of VPA trialed were 0, 200, 500, and 1,000 mg/d which resulted in a mean increase in LTG area under the curve of 83.7 +/- 14.7% at 200 mg VPA/d, to and 160 +/- 37.9% at 1,000 mg VPA/d. The presence of concomitant enzyme inducers in some patients did not influence the percentage increase from baseline in half-life observed, although clearly those on inducers started from a lower absolute half-life as a result of the induction. The effect was shown to be quite variable, particularly at the highest dosage of VPA tested (1,000 mg/d), suggesting that this effect could be best applied with the support of the therapeutic drug monitoring laboratory determining plasma LTG concentrations to allow individualization of the LTG dosage.     

Safety and pharmacokinetic studies of silodosin, a new α1A-adrenoceptor selective antagonist, in healthy Chinese male subjects

The objectives of the study were to assess the safety and pharmacokinetics of silodosin capsules in 82 healthy male Chinese subjects. To evaluate the safety after single-dosing escalation, 40 subjects were equally divided into 4 groups (2, 4, 8, 12 mg) by a randomized, double-blind and placebo-controlled design. To assess the pharmacokinetics after single-dosing, 30 subjects were equally divided into 3 groups (4, 8, 12 mg). To assess the safety and pharmacokinetics via multiple-dosing, 12 subjects were included as a group (4 mg once daily at day 1 and day 7; 4 mg twice daily at day 2 through day 6). The safety observations showed that mild adverse events, including postural hypotension, dizziness, and headache, were observed. After single-dosing at doses of 4, 8, and 12 mg, the mean area under the concentration-time curve from 0 to 36 h (AUC(0-36)) values were 136.82±46.38, 270.17±54.66, and 474.63±108.50 μg/l·h and the mean maximal silodosin concentration in plasma (C(max)) values were 26.70±7.48, 48.47±12.35, and 94.07±22.59 μg/l, respectively. After multiple-dosing, the C(max) value at day 7 was 33.84±19.54 μg/l, and the AUC(0-24) value at day 7 was 193.19±68.96 μg/l·h. The accumulation ratio of the AUC value was 1.55 by comparing the multiple-dosing with the single-dosing. It is concluded that silodosin is safe and tolerated in healthy Chinese male subjects at the dosing levels used in this study. The mean C(max) and AUC values of silodosin increased proportionally with dose escalation, showing characteristics of linear pharmacokinetics.     

Bioequivalence and pharmacokinetics of a compound sustained-release formulation of Nifedipine plus atenolol in healthy subjects

AIM： Nifedipine and atenolol are the representative drugs for calcium antagonists and 13-blockers, their combination use is the highly acclaimed anti-hypertension programs in clinical application. In order to assess the interaction of the two drugs, the bioequivalence and pharmacokinetics were investigated in a double layer tablet of compound formulation containing a sustained-release （SR） Nifedipine plus an immediate-release（IR） atenolol, compared with atenolol-IR tablet and Nifedipine-IR tablet individually in healthy Chinese subjects. METHODS： There were two stage tests： single-dose and multi-dose. In single-dose test, two random cross-over studies were performed in 20 young subjects who were given as monotherapy, a compound tablet （tested-drug, containing Nifedipine-SR 10 mg and atenolol-IR 25 mg） or two individual tablets （control-drug, a single Nifedipine-IR 10mg and a single atenolol-IR 25 mg） followed by a 12-hour-fast. In multi-dose test, two cross-over studies were performed in another 18 young subjects who were continuously treated for 7-days by two compound tablets once daily or two individual tablets （a single Nifedipine-IR 10 mg and a single atenolol-IR 25 mg） twice daily. The blood samples were collected at different time points before and after drug administration. Plasma drug concentrations were assessed by determining atenolol and Nifedipine with a validated HPLC or GC method. Safety and tolerance were evaluated by monitoring adverse events and laboratory parameters.[第一段]     

In vitro assessment of the roles of drug transporters in the disposition and drug–drug interaction potential of olaparib

1.?In vitro assessments were conducted to examine interactions between olaparib (a potent oral inhibitor of poly[ADP-ribose] polymerase) and drug transporters.

2.?Olaparib showed inhibition of the hepatic drug uptake transporters OATP1B1 (IC₅₀ values of 20.3?μM and 27.1?μM) and OCT1 (IC₅₀ 37.9?μM), but limited inhibition of OATP1B3 (25% at 100?μM); inhibition of the renal uptake transporters OCT2 (IC₅₀ 19.9?μM) and OAT3 (IC₅₀ 18.4?μM), but limited inhibition of OAT1 (13.5% at 100?μM); inhibition of the renal efflux transporters MATE1 and MATE2K (IC₅₀s 5.50?μM and 47.1?μM, respectively); inhibition of the efflux transporter MDR1 (IC₅₀ 76.0?μM), but limited inhibition of BCRP (47% at 100?μM) and no inhibition of MRP2. At clinically relevant exposures, olaparib has the potential to cause pharmacokinetic interactions via inhibition of OCT1, OCT2, OATP1B1, OAT3, MATE1 and MATE2K in the liver and kidney, as well as MDR1 in the liver and GI tract. Olaparib was found to be a substrate of MDR1 but not of several other transporters.

3.?Our assessments indicate that olaparib is a substrate of MDR1 and may cause clinically meaningful inhibition of MDR1, OCT1, OCT2, OATP1B1, OAT3, MATE1 and MATE2K.     

Cannabis use in a Swiss male prison: Qualitative study exploring detainees’ and staffs’ perspectives

BackgroundSeveral studies suggest a high prevalence of cannabis use before and during imprisonment, but subjective perspectives of detainees and staff towards its use in prison are lacking. This issue was explored in the framework of an observational study addressing tobacco use in three Swiss prisons in 2009 and 2010 that involved multiple strands (quantitative and qualitative components). This article presents qualitative data on cannabis use collected in one of the settings.MethodsWe used in-depth semi-structured interviews with both detainees and staff to explore their attitudes towards cannabis in one post-trial male Swiss prison. We performed specific coding and thematic analysis for cannabis with the support of ATLAS.ti, compared detainees’ and staff's opinions, and considered the results with regard to drug policy in prison in general.Results58 participants (31 male offenders, mean age 35 years, and 27 prison staff, mean age 46 years, 33% female) were interviewed.Detainees estimated the current use of cannabis use to be as high as 80%, and staff 50%. Participants showed similar opinions on effects of cannabis use that were described both at individual and institutional levels: analgesic, calming, self-help to go through the prison experience, relieve stress, facilitate sleep, prevent violence, and social pacifier. They also mentioned negative consequences of cannabis use (sleepiness, decreased perception of danger and social isolation), and dissatisfaction regarding the ongoing ambiguous situation where cannabis is forbidden but detection in the urine was not sanctioned. However, the introduction of a more restrictive regulation induced fear of violence, increased trafficking and a shift to other drug use.ConclusionAlthough illegal, cannabis use is clearly involved in daily life in prison. A clearer and comprehensive policy addressing cannabis is needed, including appropriate measures tailored to individual users. To sustain a calm and safe environment in prison, means other than substance or medication use are required.