'Cough-triggered' tuberculosis screening among adults with diabetes in Tanzania.

AIMS: Diabetes increases the risk of tuberculosis and the prevalence of diabetes is rising in tuberculosis-endemic regions such as sub-Saharan Africa. Resource-appropriate strategies for tuberculosis case finding among African adults with diabetes are needed. The aims of this study were to determine prevalence of tuberculosis and evaluate one screening strategy among adult Tanzanians with diabetes. METHODS: In this prospective cohort study, we evaluated a 'cough-triggered' strategy for tuberculosis case finding among adults with diabetes at our zonal hospital in Tanzania. All adults with diabetes and cough underwent further tuberculosis symptom assessment, and those with productive cough had sputum collected for microscopy and Mycobacterium tuberculosis culture. RESULTS: Between September 2011 and March 2012, 700 adults with diabetes attended our hospital. A total of 693 were enrolled, 121/693 (17.5%) had cough and 32/693 (4.6%) had at least two of the classic symptoms of tuberculosis. Of note, 87/121 (71.9%) of patients with cough could not produce sputum spontaneously. Nine patients were diagnosed with tuberculosis for a prevalence of 1299/100 000 (1.3%), sevenfold greater than the national average. CONCLUSIONS: Tuberculosis is common among Tanzanian adults with diabetes, but tuberculosis case finding is challenging because of the high prevalence of non-productive cough. This low-cost, 'cough-triggered' tuberculosis case-finding strategy may serve as a reasonable first step for improving tuberculosis screening among adults with diabetes in sub-Saharan Africa.

Clinical determinants of a positive visual inspection after treatment with acetic acid for cervical cancer screening.

OBJECTIVE: To examine the determinants of a positive visual inspection after acetic acid (VIA), including the relationship of testing positive for high-risk human papillomavirus (HR-HPV), which is the necessary cause of cervical cancer. DESIGN: A prospective cohort study. SETTING: Three clinical sites in rural China. POPULATION: A total of 7541 women aged 25-65 years. METHODS: All women underwent VIA, DNA testing, by two DNA tests performed on both clinician- and self-collected specimens, and HPV E6 oncoprotein testing. Those positive by any test underwent colposcopy and four-quadrant biopsy evaluation. A random sample of women with negative screening results also underwent colposcopy and, if colposcopic abnormalities were observed, four-quadrant biopsy evaluation was performed. Women diagnosed with cervical intraepithelial neoplasia grade 2 (CIN2), or more severe grades (CIN2 + ), underwent treatment. MAIN OUTCOME MEASURE: Testing positive for VIA. RESULTS: Overall, 7.6% (95% confidence interval, 95% CI, 7.0-8.2%) had a positive VIA. Women who tested positive for HPV were more likely to have a positive VIA than women who tested negative for HPV (15.0%, 95% CI 12.9-17.2% versus 6.3%, 95% CI 5.7-6.9%; P < 0.001). Older women were less likely to have a positive VIA (Ptrend  < 0.001), including women with CIN2 +  (Ptrend  < 0.001). A logistic regression model demonstrated that diagnosis (CIN2 +  versus

The state of hepatitis B and C in the Mediterranean and Balkan countries: report from a summit conference.

The burden of disease due to chronic viral hepatitis constitutes a global threat. In many Balkan and Mediterranean countries, the disease burden due to viral hepatitis remains largely unrecognized, including in high-risk groups and migrants, because of a lack of reliable epidemiological data, suggesting the need for better and targeted surveillance for public health gains. In many countries, the burden of chronic liver disease due to hepatitis B and C is increasing due to ageing of unvaccinated populations and migration, and a probable increase in drug injecting. Targeted vaccination strategies for hepatitis B virus (HBV) among risk groups and harm reduction interventions at adequate scale and coverage for injecting drug users are needed. Transmission of HBV and hepatitis C virus (HCV) in healthcare settings and a higher prevalence of HBV and HCV among recipients of blood and blood products in the Balkan and North African countries highlight the need to implement and monitor universal precautions in these settings and use voluntary, nonremunerated, repeat donors. Progress in drug discovery has improved outcomes of treatment for both HBV and HCV, although access is limited by the high costs of these drugs and resources available for health care. Egypt, with the highest burden of hepatitis C in the world, provides treatment through its National Control Strategy. Addressing the burden of viral hepatitis in the Balkan and Mediterranean regions will require national commitments in the form of strategic plans, financial and human resources, normative guidance and technical support from regional agencies and research.

Atrial fibrillation and mortality in outpatients with heart failure in Tanzania: a prospective cohort study.

OBJECTIVE: In recent years, the prevalence and mortality of heart failure (HF) and other associated cardiovascular diseases have doubled in sub-Saharan Africa (SSA). Studies in high-income countries indicate that HF with concurrent atrial fibrillation (AF) is linked to increased mortality. Our objective was to determine the incidence and clinical outcomes of AF among patients with HF in SSA. DESIGN: A prospective cohort study using data collected between October 2018 and May 2020. SETTING: Outpatient clinic at a tertiary hospital in Mwanza, Tanzania. PARTICIPANTS: 303 adult participants (aged ≥18 years) with HF as defined by the European Society of Cardiology guidelines (2016) and 100 adults with HF as defined by clinical criteria alone were enrolled into the study. Patients with comorbid medical condition that had prognosis of <3 months (ie, advance solid tumours, advance haematological malignancies) were excluded. METHODS: Participants were screened for AF, and their medical history, physical examinations and sociodemographic information were obtained. Multivariable logistic regression models were used to examine factors associated with AF incidence. Cox regression models were used to analyse 3-month mortality and its associated risk factors. RESULTS: We enrolled 403 participants with HF (mean age 60±19 years, 234 (58%) female). The AF prevalence was 17%. In multivariable models, factors associated with AF were low income, alcohol consumption and longer duration of HF. At the end of the 3-month follow-up, 120 out of 403 (30%) participants died, including 44% (31/70) of those with AF. Higher heart rate on ECG, more severe New York Heart Association HF class, rural residence and anaemia were significantly correlated with mortality. CONCLUSION: AF is common, underdiagnosed and is associated with significant mortality among outpatients with HF in Tanzania (HR 1.749, 95% CI 1.162 to 2.633, p=0.007). Our findings additionally identify tachycardia (>110 bpm, HR 1.879, 95% CI 1.508 to 2.340, p<0.001) as an easily measurable, high-impact physical examination finding for adverse outcomes in patients with HF.

Development of a hardened THz energy meter for use on the kilojoule-scale, short-pulse OMEGA EP laser.

A highly adaptable and robust terahertz (THz) energy meter is designed and implemented to detect energetic THz pulses from high-intensity (>1018 W/cm2) laser-plasma interactions on the OMEGA EP. THz radiation from the laser driven target is detected by a shielded pyrometer. A second identical pyrometer is used for background subtraction. The detector can be configured to detect THz pulses in the 1 mm to 30 µm (0.3- to 10-THz) range and pulse energies from joules to microjoules via changes in filtration, aperture size, and position. Additional polarization selective filtration can also be used to determine the THz pulse polarization. The design incorporates significant radiation and electromagnetic pulse shielding to survive and operate within the OMEGA EP radiation environment. We describe the design, operational principle, calibration, and testing of the THz energy meter. The pyrometers were calibrated using a benchtop laser and show linear sensitivity to up to 1000 nJ of absorbed energy. The initial results from four OMEGA EP THz experiments detected up to ∼15µJ at the detector, which can correspond to hundreds of mJ depending on THz emission and reflection models.

Collaborative home medicines review delays time to next hospitalization for warfarin associated bleeding in Australian war veterans.

WHAT IS KNOWN AND BACKGROUND: Unintended bleeds are a common complication of warfarin therapy. We aimed to determine the impact of general practitioner-pharmacist collaborative medication reviews in the practice setting on hospitalization-associated bleeds in patients on warfarin. METHOD: We undertook a retrospective cohort study using administrative claims data for the ambulatory veteran and war widow population, Australia. Participants were veterans, war widows and their dependents aged 65 years and over dispensed warfarin. The exposed groups were those exposed to a general practitioner (GP)-pharmacist collaborative home medication review. The service includes GP referral, a home visit by an accredited pharmacist to identify medication-related problems, a pharmacist report with follow-up undertaken by the GP. The outcome measure was time to next hospitalization for bleeding. RESULTS: There were 816 veterans exposed to a home medicines review and 16,320 unexposed patients, with an average age of 81.5 years, and six to seven co-morbidities. Adjusted results showed a 79% reduction in likelihood of hospitalization for bleeding between 2 and 6 months (HR, 0.21 95% CI, 0.05-0.87) amongst those who had received a home medicines reviewed compared to the unexposed patients. No effect was seen in the time period from review to 2 months, nor in the time period 6 to 12 months post a review. WHAT IS NEW AND CONCLUSION: Medicines review in the practice setting delays time to next hospitalization for bleeding in those treated with warfarin in the period 2 to 6 months after the review, but is not sustained over time. Six monthly medication reviews may be required for patients on warfarin who are considered at high risk of bleeding.

Major epiplasmic proteins of ciliates are articulins: cloning, recombinant expression, and structural characterization.

The cytoskeleton of certain protists comprises an extensive membrane skeleton, the epiplasm, which contributes to the cell shape and patterning of the species-specific cortical architecture. The isolated epiplasm of the ciliated protist Pseudomicrothorax dubius consists of two major groups of proteins with molecular masses of 78-80 kD and 11-13 kD, respectively. To characterize the structure of these proteins, peptide sequences of two major polypeptides (78-80 kD) as well as a cDNA representing the entire coding sequence of a minor and hitherto unidentified component (60 kD; p60) of the epiplasm have been determined. All three polypeptides share sequence similarities. They contain repeated valine- and proline-rich motifs of 12 residues with the consensus VPVP--V-V-V-. In p60 the central core domain consists of 24 tandemly repeated VPV motifs. Within the repeat motifs positively and negatively charged residues, when present, show an alternating pattern in register with the V and P positions. Recombinant p60 was purified in 8 M urea and dialyzed against buffer. Infrared spectroscopic measurements indicate 30% beta-sheet. Electron microscopy reveals short filamentous polymers with a rather homogenous diameter (approximately 15-20 nm), but variable lengths. The small polymers form thicker filaments, ribbons, and larger sheets or tubes. A core domain similar to that of P. dubius p60 is also found in the recently described epiplasmic proteins of the flagellate Euglena, the so-called articulins. Our results show that the members of this protein family are not restricted to flagellates, but are also present in the distantly related ciliates where they are major constituents of the epiplasm. Comparison of flagellate and ciliate articulins highlights common features of this novel family of cytoskeletal proteins.

Polypharmacy management among Australian veterans: improving prescribing through the Australian Department of Veterans' Affairs' prescriber feedback programme.

BACKGROUND: Older patients are potentially at risk from the effects of polypharmacy (PP) and/or drug-drug interactions. AIMS: To examine the effects of a targeted patient-specific prescriber feedback programme on patients prescribed more than 19 individual medications over the 3-month study period. METHODS: The Commonwealth Department of Veterans' Affairs commissioned a review of Repatriation Pharmaceutical Benefit Scheme claims data to identify patients potentially at risk of drug injury through either PP (> or =20 unique medications during 3 months) or clinically significant drug interactions (DI). Dispensing information for the patient at risk, relevant clinical guidelines and a personalized covering letter were mailed to the main prescribing general practitioner of the identified veteran patient. The claims data were then re-analysed after the programme. RESULTS: There was a significant reduction in the mean number of unique medications prescribed over a 3-month period 1 year after the prescriber feedback (mean change = -2.22; 95% confidence interval -3.54 to -0.90; P = 0.0013) for patients identified with ongoing PP. There was also a significant reduction in the number of DI pairs (mean change = -0.73; 95% confidence interval -0.77 to -0.69; P < 0.0001) for the patients identified with an ongoing DI. The number of patients dispensed one or more DI pairs decreased from 836 to 318 after the feedback. CONCLUSION: A targeted prescriber feedback programme can influence general practitioner prescribing at an individual patient level and, therefore, contribute to the quality use of medicines.

Depression screening in HIV-positive Tanzanian adults: comparing the PHQ-2, PHQ-9 and WHO-5 questionnaires.

BACKGROUND: HIV-positive individuals are at significantly increased risk of depression. In low- and middle-income countries, depression is frequently under-detected, hampered by a lack of data regarding available screening tools. The 5-item World Health Organization Well-Being Index (WHO-5) is widely used to screen for depression, yet its validity in African adults with HIV has yet to be examined. METHODS: In this cross-sectional study, we enrolled HIV-positive adults presenting to an outpatient HIV clinic in Mwanza, Tanzania. Patients were administered the Patient Health Questionnaires (PHQ)-2/9 and WHO-5 questionnaires. The rate of positive screens was calculated. Fisher's exact test and Pearson's correlation coefficients between PHQ-2/9 and WHO-5 scores were calculated. RESULTS: We enrolled 72 HIV-positive adults: rates of positive depression screen were 62.5%, 77.8%, and 47.2% according to PHQ-2, PHQ-9, and WHO-5, respectively. PHQ and WHO results for depression were significantly associated (Fisher's exact test: PHQ-2 v. WHO-5, p = 0.028; PHQ-9 v. WHO-5, p = 0.002). The level of correlation between PHQ and WHO results for depression was moderate (Pearson's correlation coefficient: PHQ-2 v. WHO-5 -0.3289; PHQ-9 v. WHO-5 -0.4463).Per Mantel-Haenszel analysis, screening results were significantly more concordant among patients in the following strata: men, age >40, Sukuma ethnicity, Christian, unmarried, self-employed, at least primary school education completed, and higher than the median income level. CONCLUSIONS: WHO-5 scores correlated well with those of the PHQ-9, suggesting that the WHO-5 represents a valid screening tool. The concordance of PHQ-9 and WHO-5 results was poorer in marginalized socioeconomic groups. Positive depression screens were exceedingly common among HIV-positive Tanzanian adults according to all three questionnaires.

Intraocular pressure alterations following intravitreal triamcinolone acetonide.

AIMS: To determine the prevalence of intraocular pressure (IOP) alterations following intravitreal injection of triamcinolone acetonide (IVTA) and to assess possible risk factors of IOP elevation in eyes receiving single and/or repeat injections. METHODS: Retrospective, consecutive case series. 570 consecutive eyes of 536 patients who received a single IVTA injection (4 mg/0.1 ml) and a second set of 43 eyes of 40 patients who received a second injection. Retrospective review of all IVTA cases performed by three vitreoretinal surgeons over a 42 month period beginning in 2000. The main outcome measure was change in IOP defined as absolute value of IOP elevation (5 mm Hg or higher, 10 mm Hg or higher), and percentage of baseline (30% or higher increase from baseline IOP). RESULTS: Of the 528 eyes receiving single injections, 281 (53.2%) had an IOP elevation; 267 eyes (50.6%) experienced an elevation of IOP of at least 30%, and 245 (45.8%) and 75 (14.2%) eyes had an increase of 5 mm Hg or 10 mm Hg or more, respectively. Baseline IOP greater than 16 mm Hg is a risk factor for post-injection IOP elevation. Of the 43 eyes which received a second injection, 28 (65.1%) experienced an increase in IOP of at least 30% of baseline. Filtering surgery was required in five (0.094%) of the single and one (2.3%) of repeat injection eyes. CONCLUSIONS: Elevated IOP after IVTA is common and patients should be monitored beyond 6 months post-injection. Patients with a baseline IOP more than 16 mm Hg or receiving a second injection should be carefully monitored for an elevated IOP.

Relationships between carcinogenesis in vivo and alkylation and solvolysis in vitro.

Carcinogenic bromomethyl- and chloromethylanthracenes and benz(a)anthracenes were found to react rapidly in vitro with DNA under physiological conditions and to varying degrees with nucleotides and nucleosides. The compounds were assayed for production of lung adenomas in strain A mice and relative carcinogenic potencies were compared with in vitro alkylation and with in vitro solvolysis rates. Success at quantitative correlation with carcinogenic potency was not obtained with either in vitro parameter. However, comparable noncarcinogenic compounds lacked their marked in vitro reactivity with DNA. Some potential polynuclear electrophiles, including chloromethyl derivatives of acridine and benz(c)acridine, a hydroxymethyl and an acetoxymethyl derivative of benz(a)anthracene, an acetoxymethylanthracene, and an acridinylglycine ester, were found not to be carcinogenic in the lung adenoma test.

Pulmonary carcinogenesis by derivatives of polynuclear aromatic alkylating agents.

Simple alkylating derivatives of polycyclic aromatic hydrocarbons have been found to be much more carcinogenic in the Strain A mouse than are the parent hydrocarbons. It has also been shown that the carcinogenicity of these halomethyl hydrocarbons is not a function of the first-order solvolysis rate. The acridine antitumor agent and mutagen ICR 170, 2-methoxy-6-chloro-9-[3-(ethyl-2-chloroethyl)aminopropylamino]acridine dihydrochloride, has been shown to be a potent carcinogen in the same system when administered i.v., superseding data in the literature indicating inactivity when the drug is administered i.p. Stimulation of the immune system has been shown to have a marked inhibitory effect on the carcinogenic activity of this compound.

Bay region distortions in cyclopenta[a]phenanthrenes.

Two newly synthesized cyclopenta[a]phenanthrenes, namely the 1-methyl (VIII) and 7,11-dimethyl (VII) derivatives of the parent ketone 15,16-dihydrocyclopenta[a]phenanthren-17-one (I), have been tested for their capacity to produce skin tumors in mice. The former (VIII) is essentially inactive, whereas the latter (VII) is very potent in both repeated application and two-stage tests. X-ray crystallographic structure analyses have been carried out on seven derivatives of (I), namely its 11-methyl (II), 11,12-dimethyl (III), 11-methoxy (V), 11-ethyl (VI) and 7,11-dimethyl (VII) analogues (carcinogens), the 1-methyl derivative (VIII), and 11,12,15,16-tetrahydro-11-methyl-17-oxocyclopenta[a]phenanthrene (IV) (both non-carcinogens). The detailed molecular structures resulting from these studies have shown the effects of steric interactions and substitutions on the bay-region geometry. The methyl group on C(11) causes distortions of the molecule in the bay region. Out-of-plane distortions in the bay regions of the 11-methyl derivatives (II, III, VII) are greater than for the 11-methoxy or the 11-ethyl derivatives (V, VI). Molecules (except for III and IV) are packed in the crystals with interactions that include C = O...H interactions; this packing is in layers that are nearly parallel to each other. A hydrogen atom of the 11-methyl group appears, from computer modeling, to interact sterically with the hydrogen atom of the bay-region expoxide group in the activated diol-epoxide; this steric interaction may force one conformer of the diol-epoxide to be the predominant form, thereby accounting for the importance of a bay-region methyl group. Further computer modeling has been used to analyze possible modes of interaction of the diol-epoxides of cyclopenta[a]phenanthrenes with DNA.

Mutagenicity and cytotoxicity of nineteen heterocyclic mustards (ICR compounds) in cultured mammalian cells.

The mutagenicity and cytotoxicity of 19 ICR compounds, including 6 reported previously, have been determined in the Chinese hamster ovary/hypoxanthine-guanine phosphoribosyltransferase system. As with other physical and chemical agents, ICR 170 and 191 exhibit a phenotypic expression time of 7 to 9 days, independent of concentrations tested. Thirteen of these compounds are mutagenic. At equimolar concentrations, the compounds with the tertiary amine-type side chain (ICR 217, 340, 355, 368, 170, and 292) are more mutagenic than the compounds with the secondary amine-type side chain (ICR 449, 371, 191, and 372). All secondary amine types show a "plateau" in their concentration-dependent mutagenesis curves at 3 to 4 microM. Shortening of the side chain by one carbon (ICR 171) results in a reduced mutagenicity. Substitution of a sulfur atom for a nitrogen in the side chain (ICR 342) increases both mutagenicity and cytotoxicity. The presence of two 2-chloroethyl groups on the side chain (ICR 220) also results in greatly increased cytotoxicity and mutagenicity. When the 2-chloroethyl group of ICR 340, 372, 292, 191, or 170 is replaced by a 2-hydroxyethyl group (ICR 340-OH, 372-OH, 292-OH, 191-OH, or 170-OH), a mutagenically inactive compound results which remains toxic. Replacement of the amine linkage with an ether linkage (ICR 283) also yields a mutagenically inactive compound.

Stereochemical properties of nucleosides alkylated by activated carcinogens.

An initial stage in the mechanism of chemical carcinogenesis by "activated" carcinogenic polycyclic aromatic hydrocarbons is believed to involve alkylation of DNA. However, very high (atomic) resolution studies of alkylated DNA are not technically feasible at this time, and therefore the detailed, high-resolution three-dimensional structures of portions of alkylated DNA have been determined. The initial phase of this study (reported here) has involved the preparation of a series of adenosines and 2'-deoxyadenosines substituted at N6 by related aralkyls of differing carcinogenic potential. We report here the crystal structure determinations of four of these compounds: Compound 1, N6-(anthracenyl-9-methyl)adenosine; Compound 2, N6-(10-methyl-anthracenyl-9-methyl)adenosine; Compound 3, N6-[12-methyl-benz(a)anthracenyl-7-methyl]adenosine; and Compound 5, N6-(10-methylanthracenyl-9-methyl)-2'-deoxyadenosine. Results are compared with those for a previously published analysis Compound 6, N6-[12-methylbenz(a)anthracenyl-7-methyl]-2'-deoxyadenosine. Several results of structural interest have emerged. All five compounds have the syn-conformational relationship between the sugar (ribose or 2'-deoxyribose) and the base (adenine), in contrast to the anti arrangement in B-DNA and in nonalkylated nucleosides. In four of the five compounds, there is an intramolecular hydrogen bond between the 5'-hydroxyl group and adenine. However, in the fifth molecule, this hydrogen bond is not found, and yet the conformation is syn. This indicates that formation of this internal hydrogen bond is not a prerequisite for the adoption of the syn-conformation. In general, the overall conformations of all five compounds are similar, the base lying approximately perpendicular to the polycyclic aromatic ring system. The packing of molecules in the unit cell is also of interest because it consists of alternations of adenine and polycyclic aromatic ring systems in columns through the crystal, indicating that this may serve as a model for the interaction with DNA. The oxygen atom of the sugar ring points towards the hydrocarbon ring system of another molecule. It is premature at this stage of our study to speculate as to the effects of alkylation on the conformational properties of either RNA or DNA. The only comment that appears justified is that the propensity of these adducts to adopt the syn-conformation may be indicative of a preference of alkylated DNA for the Z-conformation (even if the form that is initially attacked is B-DNA).(ABSTRACT TRUNCATED AT 400 WORDS)

Bottom-up Meets Top-down: Complementary Physiologically Based Pharmacokinetic and Population Pharmacokinetic Modeling for Regulatory Approval of a Dosing Algorithm of Valganciclovir in Very Young Children.

Population pharmacokinetic (PopPK) and physiologically based pharmacokinetic (PBPK) models are frequently used to support pediatric drug development. Both methods have strengths and limitations and we used them complementarily to support the regulatory approval of a dosing algorithm for valganciclovir (VGCV) in children <4 months old. An existing pediatric PBPK model was extended to neonates and showed that potential physiological differences compared with older children are minor. The PopPK model was used to simulate ganciclovir (GCV) exposures in children with population typical combinations of body size and renal function and to assess the effectiveness of an alternative dosing algorithm suggested by the US Food and Drug Administration. PBPK and PopPK confirmed that the proposed VGCV dosing algorithm achieves similar GCV exposures in children of all ages and that the alternative dosing algorithm leads to underexposure in a substantial fraction of patients. Our approach raised the confidence in the VGCV dosing algorithm for children <4 months old and supported the regulatory approval.

Pulmonary TB bacteriologically confirmed by induced sputum among children at Bugando Medical Centre, Tanzania.

BACKGROUND: The diagnosis of paediatric tuberculosis (TB) remains difficult in resource-: poor settings. OBJECTIVE: To evaluate induced sputum collection and examination using microscopy, culture and Xpert(®) MTB/RIF assay for the diagnosis of pulmonary TB (PTB) in a Tanzanian hospital vs. PTB diagnosis using clinical scoring tools alone. METHODS: We conducted a cross-sectional study from October 2013 to April 2014 at our hospital in northwestern Tanzania. Children presumed to have TB were assessed using four TB score charts and sputum examination. Sputum samples were analyzed using fluorescence microscopy, solid culture and Xpert. The number of cases microbiologically confirmed was compared to the number of TB cases suspected based on TB score charts. RESULTS: A total of 192 patients were enrolled. Sputum specimens were successfully obtained in 187 (97.4%) patients without any major complications. Ten (5.2%) children were confirmed to have PTB by sputum examination. More than half (50-90%) of the confirmed cases were not detected by score charts alone. CONCLUSION: Sputum induction is both safe and feasible in a severely resource-limited hospital, and can lead to microbiological PTB diagnosis that would not be detected by clinical criteria alone.

Phase I and pharmacokinetic study of the novel MDR1 and MRP1 inhibitor biricodar administered alone and in combination with doxorubicin.

PURPOSE: To evaluate the safety, tolerability, and pharmacokinetics of biricodar (VX-710), an inhibitor of P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP1), alone and with doxorubicin in patients with advanced malignancies. The effect of VX-710 on the tissue distribution of (99m)Tc-sestamibi, a P-gp and MRP1 substrate, was also evaluated. PATIENTS AND METHODS: Patients with solid malignancies refractory to standard therapy first received a 96-hour infusion of VX-710 alone at 20 to 160 mg/m(2)/h. After a 3-day washout, a second infusion of VX-710 was begun, on the second day of which doxorubicin 45 mg/m(2) was administered. Cycles were repeated every 21 to 28 days. (99m)Tc-sestamibi scans were performed before and during administration of VX-710 alone. RESULTS: Of the 28 patients who enrolled, 25 patients were eligible for analysis. No dose-limiting toxicity (DLT) was observed in the nine assessable patients who received 120 mg/m(2)/h or less. Among seven patients receiving VX-710 160 mg/m(2)/h, two DLTs were seen: reversible CNS toxicity and febrile neutropenia. All other adverse events were mild to moderate and reversible. Plasma concentrations of VX-710 in patients who received at 120 and 160 mg/m(2)/h were two- to fourfold higher than concentrations required to fully reverse drug resistance in vitro. VX-710 exhibited linear pharmacokinetics with a harmonic mean half-life of 1.1 hours. VX-710 enhanced hepatic uptake and retention of (99m)Tc-sestamibi in all patients. CONCLUSION: A 96-hour infusion of VX-710 at 120 mg/m(2)/h plus doxorubicin 45 mg/m(2) has acceptable toxicity in patients with refractory malignancies. The safety and pharmacokinetics of VX-710 plus doxorubicin warrant efficacy trials in malignancies expressing P-gp and/or MRP1.