Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) for ovarian cancer in an Australian institution: lessons from 20 years' experience

Objectives

We report the 20-year experience of the largest Australian unit performing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for ovarian cancer and reflect on learning opportunities.

Methods

A retrospective review of all cases of CRS for ovarian cancer at St George Peritonectomy Unit from Jan 1998 to Jan 2018 was performed. Prospectively collected data include age, stage, histology, disease extent (PCI), completeness of cytoreduction (CC score), HIPEC regime, 30-day surgical morbidity, disease recurrence, and death. Survival was computed using Kaplan–Meier method and analysed using log-rank tests and Cox-proportional hazards models.

Results

Forty-one women with advanced ovarian cancer (11 primary stage III/IV, 30 recurrent) underwent CRS, 29 (71%) with HIPEC. Most (68%) had high-volume disease (PCI > 15). In 98%, CC0/CC1 (residual < 2.5 mm) was achieved. Fourteen (34%) had grade 3/4 complications, 1 patient (2%) died within 30 days and 2 patients (5%) died within 90 days. Progression-free and median overall survival was 30.0 and 67.0 months for primary cancer, and 6.7 and 18.1 months for recurrent cancer. Survival was associated with platinum-sensitivity, PCI ≤ 15, and CC score 0, but not HIPEC.

Conclusion

This study reports outcomes for patients with advanced ovarian cancer patients treated in an Australian centre offering CRS and HIPEC. Whilst survival and morbidity outcomes were good for primary disease, they were poorer than predicted from the literature for cases of recurrent disease. The incorporation of evidence-based predictors of survival and multidisciplinary input are essential to achieve the best survival outcomes.

International consensus guideline for anticancer drug dosing in kidney dysfunction (ADDIKD): A standardized approach to assessing kidney function in cancer patients and its application to anticancer drug dosing

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Background: Anticancer drug dosing recommendations in kidney dysfunction are often empirical, based on non-standardised creatinine assays calculated via the Cockcroft-Gault equation, and lack applicability to globally accepted kidney dysfunction classifications. ADDIKD aims to provide a standardised approach to assessing kidney function in cancer patients, and to apply evidence and consensus-based recommendations to anticancer drug dosing in kidney dysfunction. Methods: An expert international multidisciplinary working group was established to develop anticancer drug dosing recommendations. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to critically appraise the quality and strength of evidence and formulate recommendations. The working group participated in workshops to achieve > 80% consensus for a standardised approach to assessing and classifying levels of kidney function, its application to anticancer drug dosing in kidney dysfunction, and dosing recommendations for individual drugs. Upcoming public consultation will refine these recommendations and facilitate acceptance as an international benchmark. Results: Three key recommendations formed the basis of ADDIKD: Application of estimated glomerular filtration rate via the Chronic Kidney Disease-Epidemiology Collaboration equation (eGFRCKD-EPI) to guide the assessment of kidney function, except where directly measured glomerular filtration rate (mGFR) is clinically necessary. Where the anticancer drug dose is dependent on kidney function and mGFR is not clinically necessary, eGFRCKD-EPI is suggested to guide dosing. Application of the Kidney Disease Improving Global Outcomes (KDIGO) Chronic Kidney Disease categories to guide stepwise dose adjustments of anticancer drugs in kidney dysfunction. A review of 2263 published articles and 177 registered product information monographs enabled 127 GRADE assessments by the working party, resulting in evidence and consensus-based dosing recommendations for 59 anticancer drugs. 'Quick reference’ dosing tables incorporated a traffic light system for alerting clinicians to caution around levels of kidney function and specific patient risk factors for consideration. Conclusions: eGFRCKD-EPI is the most accurate and convenient method for assessing kidney function in diverse populations (including cancer patients) and accounts for the standardisation of the creatinine assay. ADDIKD’s expert acceptance of this standardised approach, together with anticancer drug dosing recommendations in kidney dysfunction, provides a practical tool to establish clinically relevant dosing in this patient population.

Clinical and molecular profile of young adults with early-onset colorectal cancer: Experience from four Australian tertiary centers

BACKGROUND

Patients with early-onset colorectal cancer (EO-CRC) have unique characteristics. Contemporary data on the pathological and molecular features, and survival of EO-CRC are limited in the Australian context.

AIM

To determine the demographic, histopathological and molecular characteristics of adults with EO-CRC, and their survival.

METHODS

We conducted a retrospective study of adults aged 18-49 years with EO-CRC who were referred to the Illawarra Shoalhaven Local Health District, South Eastern Sydney Local Health District and Royal North Shore Hospital in New South Wales, Australia, between 2014 and 2018.

RESULTS

Of 257 patients included, 94 (37%) patients presented with de novo metastatic CRC, 80% patients had near-average risk family history and 89% had a symptomatic presentation. In 159 patients with nonmetastatic disease at diagnosis, stage III disease (OR 3.88 [95% CI: 1.13-13.3]; p = .03) and the presence of perineural invasion (PNI) (OR 6.63 [95% CI: 2.21-19.84]; p = .001) were risk factors associated with the development of metastatic disease. Among 94 patients with de novo metastatic disease, 43 (43%) and 12 (14%) patients harbored a KRAS or BRAF V600E mutation, respectively. The median overall survival was 29.6 months (95% CI: 20.4-38.7). BRAF mutation was associated with inferior survival (HR 3.00 [95% CI: 1.30-6.94]; p = .01).

CONCLUSION

The prevalence of KRAS and BRAF mutations in our cohort is similar to the overseas experience. Stage III disease at diagnosis, presence of PNI and BRAF mutation are adverse prognostic indicators. A better understanding of the molecular landscape is needed for this patient cohort, so as to better tailor prevention strategies, screening and treatment pathways.

Making sense of a diagnosis of incurable cancer: The importance of communication

Purpose:  Patients diagnosed with incurable cancer may experience existential distressand difficulty in re-appraising their lives because of uncertainty about the future. Objectives: This study sought to understand how patients living with incurable cancer made sense of their diagnosis, how they prepared for the future and what support they wanted from their health professionals.  Subjects:  27 patients were recruited from the oncology and palliative care service at three metropolitan hospitals. Methods:  A qualitative research approach was used. Semi-structured face-to-face interviews were conducted. Interviews were audio-taped and transcribed verbatim.  Data was analyzed using the constant-comparative method.  Results:  Participants did not express a need to make sense of their diagnosis nor always ascribe to a particular religious belief; rather, many relied on a personal spirituality or philosophy to bring meaning to their experience. Importance was placed on their doctor keeping up with technology, being honest, and being confident and positive. Conclusion:  Participants in this study had incurable cancer but making sense of their current situation was not a conscious priority. For these patients, uncertainty was a positive, as certainty for them indicates death is approaching. What these interviews suggest, from the patient’s perspective, is that there is an implied contract between doctor and patient during this period which involves the doctor managing the flow of difficult information so that the patient can maintain normality for as long as possible. Understanding this helps to explain the difficulty of having advance care planning conversations within this setting, despite the many opportunities that a longer disease trajectory would seem to offer. 

Survival, mortality and morbidity outcomes after oesophagogastric cancer surgery in New South Wales, 2001-2008

OBJECTIVES

To examine the relationship between hospital volume and patient outcomes for New South Wales hospitals performing oesophagectomy and gastrectomy for oesophagogastric cancer.

DESIGN, SETTING AND PATIENTS

A retrospective, population-based cohort study of NSW residents diagnosed with a new case of invasive oesophageal or gastric cancer who underwent oesophagectomy or gastrectomy between 2001 and 2008 in NSW hospitals using linked de-identified data from the NSW Central Cancer Registry, the National Death Index and the NSW Admitted Patient Data Collection. A higher-volume hospital was defined as one performing > 6 relevant procedures per year.

MAIN OUTCOME MEASURES

Odds ratios for > 21-day length of stay, 28-day unplanned readmission, 30-day mortality and 90-day mortality, and hazard ratios (HRs) for 5-year absolute and conditional survival.

RESULTS

Oesophagectomy (908 patients) and gastrectomy (1621 patients) were undertaken in 42 and 84 hospitals, respectively, between 2001 and 2008. Median annual hospital volume ranged from 2 to 4 for oesophagectomies and ranged from 2 to 3 for gastrectomies. Controlling for known confounders, no associations between hospital volume and > 21-day length of stay and 28-day unplanned readmission were found. Overall 30-day mortality was 4.1% and 4.4% for oesophagectomy and gastrectomy, respectively. Five-year absolute survival was significantly better for patients who underwent oesophagectomy in higher-volume hospitals (adjusted HR for lower-volume hospitals, 1.28 [95% CI, 1.10-1.49]; P = 0.002) and for those with localised gastric cancer who underwent gastrectomy in higher-volume hospitals (adjusted HR for lower-volume hospitals, 1.83 [95% CI, 1.28-2.61]; P = 0.001).

CONCLUSIONS

These data support initial surgery for oesophagogastric cancer in higher-volume hospitals.

Should culture affect practice? Prognostic discussions with immigrants

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Background: Poor prognosis is difficult to impart, particularly across a cultural divide. This study is the first to compare prognostic communication with immigrants (with and without interpreters) versus native–born patients in audio-taped oncology consultations. Methods: Ten oncologists, 78 patients (31 Australian-born, 47 immigrants) and 115 family members participated. The first two consultations after diagnosis of incurable disease were audiotaped, transcribed and coded. 142 consultations were included in the analysis. Results: Fifty percent of doctor and 59% of patient prognostic speech units were notinterpreted or interpreted non-equivalently when an interpreter was present. Immigrant status predicted few, and oncologist characteristics no, prognostic facts disclosed. Oncologists were significantly less likely to convey hope to immigrants, and more likely to use medical jargon (p = 0.009) than with Australian-born patients. Incurable disease status and a limited life span were commonly acknowledged, generally with no timeframe provided. Physical issues were discussed more commonly than emotional aspects. Conclusions: While culture did not appear to influence doctor speech, interpreters filtered or blocked much prognostic communication. Initiatives to empower all patients to attain needed information, optimise communication when an interpreter is present and train cancer health professionals in culturally appropriate care, are urgently required.

Phase I study of everolimus in combination with fluvastatin and zoledronic acid in patients with solid tumours

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Background: Everolimus (E) is an mTOR inhibitor with broad anti-tumour clinical activity. There is preclinical evidence of synergistic activity through the combination of E with fluvastatin (F) and zoledronic acid (ZA). F, an HMG CoA reductase inhibitor, and ZA, a bisphosphonate, have both been shown preclinically to inhibit isoprenylation (addition of hydrophobic molecules) of key signalling proteins with subsequent inhibition of the Ras pathway. We investigate their potential activity further in this open-label phase I trial. Methods: Patients (pts) with advanced solid tumours were treated with escalating doses of E, F and ZA to evaluate safety, clinical activity, pharmacokinetics (PK), pharmacodynamics (PD) and the recommended dose for further study. PK samples were obtained over 24 hrs on day 1 and 8 of cycle 1 and day 1 of cycle 2. Pre- and post-dose PBMCs were analysed for markers of MAPK and PI3K-AKT-mTOR pathways (pERK, pAKT and pS6). Results: Maximum doses of each drug in combination (DL 4) were feasible and no DLTs were observed. Of the 16 pts evaluable [median age=63yrs (range 47-81)], the median number of cycles was 3.8 (range 1-8), with 44% of pts receiving ≥ 4 cycles. Drug related toxicities were mainly G1/2, many within the expected toxicity profile of E, including fatigue (12 pts, 75%), myalgias (9 pts, 56%), anorexia (8 pts, 50%), infection (8pts, 50%), dyspnoea (7pts, 44%), diarrhoea (7 pts, 44%), nausea (7 pts, 44%), peripheral oedema (5 pts, 31%) and mucositis (4 pts, 25%). G3 adverse events were predominantly due to symptoms of disease progression. G1/2 anemia and thrombocytopaenia were the most common haematological toxicities, particularly in DL 3 and 4. 44% of pts achieved stable disease as best response (mean 4.5m [range 3-6m]); including 2 CRC pts (DL 4) and 2 CRPC pts (DL 3 and 4). PK and PD results will be presented in further detail. Conclusions: The combination of E/F/ZA is feasible without any added or overlapping toxicities in this phase 1 study. [Table: see text]

Final analysis of the phase III randomized trial of cetuximab (CET) plus either brivanib alaninate (BRIV) or placebo in patients (pts) with chemotherapy refractory, K-RAS wild-type (WT), metastatic colorectal carcinoma (mCRC): The NCIC Clinical Trials Group and AGITG CO.20 trial

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Background: The anti-EGFR monoclonal antibody CET has improved survival in pts with chemotherapy refractory, K-RAS WT mCRC. BRIV is a potent inhibitor of multiple receptor tyrosine kinases including both VEGFR and FGFR. The combination of CET and BRIV targets tumor growth and angiogenesis and demonstrated encouraging activity in an early phase clinical trial. Methods: Pts with mCRC previously treated with combination chemotherapy were randomized 1:1 to receive CET 400 mg/m2 IV loading dose followed by weekly maintenance of 250 mg/m2 plus either BRIV 800 mg PO daily (Arm A) or placebo (Arm B). Pts may have had 1 prior anti-VEGF, but no prior anti-EGFR therapy. Primary endpoint was overall survival (OS). Results: From 02/2008 to 02/2011, 750 pts were randomized (376 in Arm A and 374 in Arm B). Demographics: median age=64 (range 27-88); male=64%; ECOG 0:1:2 (%)=32:58:10; >3 prior chemotherapy regimens=92%; prior anti-VEGF therapy=41%; K-RAS WT=97%. Primary analysis was conducted per protocol after 536 deaths were observed, with median OS of 8.8 months in Arm A and 8.1 months in Arm B, hazard ratio (HR)=0.88; 95% CI=0.74 to 1.03; p=0.12. Median progression-free survival (PFS) was 5.0 months in Arm A and 3.4 months in Arm B, HR=0.72; 95% CI=0.62 to 0.84; p<0.0001. Incidence of any ≥grade 3 adverse event (AE) was 78% in Arm A and 53% in Arm B. Time to deterioration of physical function was shorter and global quality of life scores were lower in Arm A vs Arm B. Planned subgroup analyses revealed no statistically difference in treatment effects on OS based on pre-specified factors of age, gender, ECOG and race. Likewise, no difference was detected based on exploratory subgroup analyses of LDH and prior anti-VEGF therapy. Conclusions: Despite positive effects on PFS, the combination of CET+BRIV did not significantly improve OS in pts with chemotherapy refractory, K-RAS WT mCRC. Final updated results based on 20-25% additional events for a total of nearly 700 deaths, as well as further exploratory subgroup analyses, will be presented.

Phase III randomized trial of cetuximab (CET) plus either brivanib alaninate (BRIV) or placebo in patients (pts) with metastatic (MET) chemotherapy refractory K-RAS wild-type (WT) colorectal carcinoma (CRC): The NCIC Clinical Trials Group and AGITG CO.20 trial

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Background: The anti-EGFR monoclonal antibody CET has improved survival in pts with MET, chemotherapy refractory, K-RAS wild type (WT) CRC. The addition of BRIV, a tyrosine kinase inhibitor targeting vascular endothelial and fibroblast growth factor receptors (VEGFR/FGFR), to CET has shown encouraging activity in an early phase clinical trial.

Methods: Pts with MET CRC previously treated with combination chemotherapy were randomized 1:1 to receive CET 400 mg/m2 IV loading dose followed by weekly maintenance of 250 mg/m2 plus either BRIV 800 mg PO daily (Arm A) or placebo (Arm B). Pts may have had 1 prior anti-VEGF, but no prior anti-EGFR therapy. The trial was amended shortly after opening to enrol K-RAS WT pts. Primary endpoint was overall survival (OS).

Results: From 02/2008 to 02/2011, 750 pts were randomized (376 in Arm A and 374 in Arm B). Demographics: median age=64 (range 27-88); male=64%; ECOG 0:1:2 (%)=32:58:10; >3 prior chemotherapy regimens=92%; prior anti-VEGF therapy=41%; K-RAS WT=97%. Median OS in the intent-to-treat population was 8.8 months in Arm A and 8.1 months in Arm B, hazard ratio (HR)=0.88; 95% CI=0.74 to 1.03; p=0.12. Median progression-free survival (PFS) was 5.0 months in Arm A and 3.4 months in Arm B, HR=0.72; 95% CI=0.62 to 0.84; p<0.0001. Both partial responses (13.6% vs 7.2%, p=0.004) and stable disease (50% vs 44%) were higher in Arm A. Incidence of any ≥grade 3 adverse event (AE) was 78% in Arm A and 53% in Arm B. Most frequent ≥grade 3 AEs were fatigue (25%), hypertension (11%) and rash (10%) in Arm A, vs fatigue (11%), rash (5%) and dyspnea (5%) in Arm B. Time to deterioration of physical function was shorter and global quality of life scores were lower in Arm A vs Arm B. Pts received ≥90% dose intensity of CET=57% in Arm A vs 83% in Arm B; of BRIV/placebo=48% in Arm A vs 87% in Arm B.

Conclusions: Despite positive effects on PFS and objective response, the combination of CET+BRIV did not significantly improve OS in pts with MET, chemotherapy refractory, K-RAS WT CRC. AEs were consistent with those reported for each drug given as monotherapy.

Pharmacokinetic and pharmacodynamic interactions of echinacea and policosanol with warfarin in healthy subjects

AIMS

This study investigated the pharmacokinetic and pharmacodynamic interactions of echinacea and policosanol with warfarin in healthy subjects.

METHODS

This was an open-label, randomized, three-treatment, cross-over, clinical trial in healthy male subjects (n= 12) of known CYP2C9 and VKORC1 genotype who received a single oral dose of warfarin alone or after 2 weeks of pre-treatment with each herbal medicine at recommended doses. Pharmacodynamic (INR, platelet activity) and pharmacokinetic (warfarin enantiomer concentrations) end points were evaluated.

RESULTS

The apparent clearance of (S)-warfarin (90% CI of ratio; 1.01, 1.18) was significantly higher during concomitant treatment with echinacea but this did not lead to a clinically significant change in INR (90% CI of AUC of INR; 0.91, 1.31). Policosanol did not significantly affect warfarin enantiomer pharmacokinetics or warfarin response. Neither echinacea nor policosanol had a significant effect on platelet aggregation after 2 weeks of pre-treatment with the respective herbal medicines.

CONCLUSION

Echinacea significantly reduced plasma concentrations of S-warfarin. However, neither echinacea nor policosanol significantly affected warfarin pharmacodynamics, platelet aggregation or baseline clotting status in healthy subjects.

Pharmacodynamic interaction of warfarin with cranberry but not with garlic in healthy subjects

BACKGROUND AND PURPOSE

Patients commonly take complementary medicines in conjunction with warfarin yet evidence supporting the safety or the risk of a herb-drug interaction is lacking. The aim of this study was to investigate the possible impact of two commonly used herbal medicines, garlic and cranberry, on the pharmacokinetics and pharmacodynamics of warfarin in healthy male subjects.

EXPERIMENTAL APPROACH

An open-label, three-treatment, randomized crossover clinical trial was undertaken and involved 12 healthy male subjects of known CYP2C9 and VKORC1 genotype. A single dose of 25 mg warfarin was administered alone or after 2 weeks of pretreatment with either garlic or cranberry. Warfarin enantiomer concentrations, INR, platelet aggregation and clotting factor activity were measured to assess pharmacokinetic and pharmacodynamic interactions between warfarin and herbal medicines.

KEY RESULTS

Cranberry significantly increased the area under the INR-time curve by 30% when administered with warfarin compared with treatment with warfarin alone. Cranberry did not alter S- or R-warfarin pharmacokinetics or plasma protein binding. Co-administration of garlic did not significantly alter warfarin pharmacokinetics or pharmacodynamics. Both herbal medicines showed some evidence of VKORC1 (not CYP2C9) genotype-dependent interactions with warfarin, which is worthy of further investigation.

CONCLUSIONS AND IMPLICATIONS

Cranberry alters the pharmacodynamics of warfarin with the potential to increase its effects significantly. Co-administration of warfarin and cranberry requires careful monitoring.

Effects of St John's wort and CYP2C9 genotype on the pharmacokinetics and pharmacodynamics of gliclazide

BACKGROUND AND PURPOSE

Patients commonly take complementary medicines in conjunction with conventional drugs without clear evidence of safety or the risk of herb-drug interactions. The aim of this study was to assess potential pharmacokinetic (PK) and pharmacodynamic (PD) interactions between St John's wort and gliclazide in healthy subjects with different cytochrome P450 2C9 (CYP2C9) genotypes.

EXPERIMENTAL APPROACH

A crossover controlled study was conducted in 21 healthy subjects. Each received gliclazide (80 mg) either alone or during 15 days treatment with St John's wort. The area under the plasma concentration-time curve (AUC(0-infinity)), apparent clearance (CL/F) and elimination half-life (t 1/2) of gliclazide and incremental changes in glucose and insulin AUC(0-4) were compared. CYP2C9*2 and CYP2C9*3 alleles were identified using PCR followed by restriction enzyme digestion analysis.

KEY RESULTS

St John's wort significantly altered gliclazide pharmacokinetics in all except for four healthy subjects. The mean ratio and 90% confidence interval (CI) of gliclazide AUC(0-infinity) and CL/F were 0.67 (0.55-0.81) and 1.50 (1.24-1.81), respectively, after St John's wort treatment. St John's wort decreased gliclazide t (1/2), with mean ratio and 90% CI of 0.85 (0.74-0.93). There were no significant changes in glucose or insulin AUC(0-4) after St John's wort treatment and no significant differences according to CYP2C9 genotype.

CONCLUSIONS AND IMPLICATIONS

Treatment with St John's wort significantly increases the apparent clearance of gliclazide which is independent of CYP2C9 genotype. People with diabetes receiving this combination should be closely monitored to evaluate possible signs of reduced efficacy.

Cytochrome P450 2B6 activity as measured by bupropion hydroxylation: effect of induction by rifampin and ethnicity

AIM

The aim of this study was to investigate the activity of the drug-metabolizing enzyme cytochrome P450 (CYP) 2B6 before and after in vivo induction by rifampin (INN, rifampicin) in white subjects and Chinese subjects by use of the probe drug bupropion (INN, amfebutamone).

METHODS

Healthy male white subjects (n = 9) and Chinese subjects (n = 9) (age range, 19-34 years) of known CYP2B6 genotype received orally administered bupropion (Zyban SR, 150 mg) alone and during daily treatment with rifampin (600 mg). Blood samples were taken for up to 72 hours after each bupropion dose, and plasma concentrations of bupropion and its active metabolites, hydroxybupropion, threohydrobupropion, and erythrohydrobupropion, were measured by HPLC. The subjects' CYP2B6 genotype was determined by use of a matrix-assisted laser desorption /ionization-time of flight (MALDI-TOF) mass spectrometry assay.

RESULTS

Rifampin treatment increased the apparent clearance of bupropion in Chinese subjects and white subjects combined (n = 16) from 2.6 L x h(-1) x kg(-1) (95% confidence interval [CI], 2.3-3.0 L x h(-1) x kg(-1)) after bupropion alone to 7.9 L x h(-1) x kg(-1) (95% CI, 6.8-10.1 L x h(-1) x kg(-1)) during rifampin treatment. Rifampin treatment decreased the half-life of bupropion from 15.9 hours (95% CI, 13.5-20.4 hours) to 8.2 hours (95% CI, 6.7-12.4 hours). Rifampin treatment increased the hydroxybupropion maximum concentration from 395 ng/mL (95% CI, 341-497 ng/mL) to 548 ng/mL (95% CI, 490-638 ng/mL), decreased the area under the concentration-time curve extrapolated to infinity of hydroxybupropion from 14.7 microg x h/mL (95% CI, 12.7-18.4 microg x h/mL) to 8.4 microg x h/mL (95% CI, 7.4-10.2 microg x h/mL), and reduced the elimination half-life of hydroxybupropion from 21.9 hours (95% CI, 20.3-24.0 hours) to 10.7 hours (95% CI, 8.6-14.5 hours). There was no significant difference in the pharmacokinetics of bupropion or hydroxybupropion between white subjects and Chinese subjects before and after treatment with rifampin, once corrected for body weight.

CONCLUSIONS

Rifampin significantly induces CYP2B6 activity in vivo, and the clinical consequences of potential interactions between rifampin and CYP2B6 substrates deserve further investigation. Rifampin appears to induce the elimination of hydroxybupropion. Differences in bupropion pharmacokinetics that were observed between white subjects and Chinese subjects can be attributed to differences in body weight, suggesting that, for a given subject weight, CYP2B6 activity is similar in white subjects and Chinese subjects.

Tailoring access to high cost, genetically targeted drugs

Assessment of real cost effectiveness, with data linked to individual health outcomes while protecting patient privacy, is an essential challenge we need to meet.

Effect of ginkgo and ginger on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects

AIM

The aim of this study was to investigate the effect of two common herbal medicines, ginkgo and ginger, on the pharmacokinetics and pharmacodynamics of warfarin and the independent effect of these herbs on clotting status.

METHODS

This was an open label, three-way crossover randomized study in 12 healthy male subjects, who received a single 25 mg dose of warfarin alone or after 7 days pretreatment with recommended doses of ginkgo or ginger from herbal medicine products of known quality. Dosing with ginkgo or ginger was continued for 7 days after administration of the warfarin dose. Platelet aggregation, international normalized ratio (INR) of prothrombin time, warfarin enantiomer protein binding, warfarin enantiomer concentrations in plasma and S-7-hydroxywarfarin concentration in urine were measured. Statistical comparisons were made using anova and the 90% confidence intervals (CIs) of the ratio of log transformed parameters are reported.

RESULTS

INR and platelet aggregation were not affected by administration of ginkgo or ginger alone. The mean (95% CI) apparent clearances of S-warfarin after warfarin alone, with ginkgo or ginger were 189 (167-210) ml h(-1), 200 (173-227) ml h(-1) and 201 (171-231) ml h(-1), respectively. The respective apparent clearances of R-warfarin were 127 (106-149) ml h(-1), 126 (111-141) ml h(-1) and 131 (106-156) ml h(-1). The mean ratio (90% CI) of apparent clearance for S-warfarin was 1.05 (0.98-1.21) and for R-warfarin was 1.00 (0.93-1.08) when coadministered with ginkgo. The mean ratio (90% CI) of AUC(0-168) of INR was 0.93 (0.81-1.05) when coadministered with ginkgo. The mean ratio (90% CI) of apparent clearance for S-warfarin was 1.05 (0.97-1.13) and for R-warfarin was 1.02 (0.95-1.10) when coadministered with ginger. The mean ratio (90% CI) of AUC(0-168) of INR was 1.01 (0.93-1.15) when coadministered with ginger. The mean ratio (90% CI) for S-7-hydroxywarfarin urinary excretion rate was 1.07 (0.85-1.32) for ginkgo treatment, and 1.00 (0.81-1.23) for ginger coadministration suggesting these herbs did not affect CYP2C9 activity. Ginkgo and ginger did not affect the apparent volumes of distribution or protein binding of either S-warfarin or R-warfarin.

CONCLUSIONS

Ginkgo and ginger at recommended doses do not significantly affect clotting status, the pharmacokinetics or pharmacodynamics of warfarin in healthy subjects.

Effect of St John's wort and ginseng on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects

M: The aim of this study was to investigate the effect of St John's wort and ginseng on the pharmacokinetics and pharmacodynamics of warfarin.

METHODS

This was an open-label, three-way crossover randomized study in 12 healthy male subjects, who received a single 25-mg dose of warfarin alone or after 14 days' pretreatment with St John's wort, or 7 days' pretreatment with ginseng. Dosing with St John's wort or ginseng was continued for 7 days after administration of the warfarin dose. Platelet aggregation, international normalized ratio (INR) of prothrombin time, warfarin enantiomer protein binding, warfarin enantiomer concentrations in plasma and S-7-hydroxywarfarin concentration in urine were measured. Statistical comparisons were made using anova and 90% confidence intervals are reported.

RESULTS

INR and platelet aggregation were not affected by treatment with St John's wort or ginseng. The apparent clearances of S-warfarin after warfarin alone or with St John's wort or ginseng were, respectively, 198 +/- 38 ml h(-1), 270 +/- 44 ml h(-1) and 220 +/- 29 ml h(-1). The respective apparent clearances of R-warfarin were 110 +/- 25 ml h(-1), 142 +/- 29 ml h(-1) and 119 +/- 20 ml h(-1) [corrected]. The mean ratio and 90% confidence interval (CI) of apparent clearance for S-warfarin was 1.29 (1.16, 1.46) and for R-warfarin it was 1.23 (1.11, 1.37) when St John's wort was coadministered. The mean ratio and 90% CI of AUC(0-168) of INR was 0.79 (0.70, 0.95) when St John's wort was coadministered. St John's wort and ginseng did not affect the apparent volumes of distribution or protein binding of warfarin enantiomers.

CONCLUSIONS

St John's wort significantly induced the apparent clearance of both S-warfarin and R-warfarin, which in turn resulted in a significant reduction in the pharmacological effect of rac-warfarin. Coadministration of warfarin with ginseng did not affect the pharmacokinetics or pharmacodynamics of either S-warfarin or R-warfarin.

Adverse event reporting in clinical trials: room for improvement

Regulatory and ethical guidelines require clinical trial sponsors to disseminate clinical trial adverse event reports to involved investigators and human research ethics committees. Compliance with these guidelines has resulted in a major administrative burden for ethics committees. This burden does not necessarily contribute to the protection of clinical trial participants. Rationalisation of the adverse event reporting might allow better use of the data and might benefit human research ethics committees.