Population pharmacokinetics and pharmacodynamics of garenoxacin in patients with community-acquired respiratory tract infections

Garenoxacin (T-3811ME, BMS-284756) is a novel, broad-spectrum des-F(6) quinolone currently under study for the treatment of community-acquired respiratory tract infections. This analysis assessed garenoxacin population pharmacokinetics and exposure-response relationships for safety (adverse effects [AE]) and antimicrobial activity (clinical cure and bacteriologic eradication of Streptococcus pneumoniae and the grouping of Haemophilus influenzae, Haemophilus parainfluenzae, and Moraxella catarrhalis). Data were obtained from three phase II clinical trials of garenoxacin administered orally as 400 mg once daily for 5 to 10 days for the treatment of community-acquired pneumonia, acute exacerbation of chronic bronchitis, and sinusitis. Samples were taken from each patient before drug administration, 2 h following administration of the first dose, and on the day 3 to 5 visit. Individual Bayesian estimates of the fu (fraction unbound), the Cmax, and the fu for the area under the concentration-time curve from 0 to 24 h (fu AUC(0-24)) were calculated as measurements of drug exposure by using an ex vivo assessment of average protein binding. Regression analysis was performed to examine the following relationships: treatment-emergent AE incidence and AUC(0-24), Cmax, or patient factors; clinical response or bacterial eradication and drug exposure (fu Cmax/MIC, fu AUC(0-24)/MIC, and other exposure covariates); or disease and patient factors. Garenoxacin pharmacokinetics were described by a one-compartment model with first-order absorption and elimination. Clearance was dependent on creatinine clearance, ideal body weight, age, obesity, and concomitant use of pseudoephedrine. The volume of distribution was dependent on weight and gender. Patients with mild or moderate renal dysfunction had, on average, approximately a 16 or 26% decrease in clearance, respectively, compared to patients of the same gender and obesity classification with normal renal function. AE occurrence was not related to garenoxacin exposure. Overall, clinical cure and bacterial eradication rates were 91 and 90%, respectively, for S. pneumoniae and 93 and 92%, respectively, for the grouping of H. influenzae, H. parainfluenzae, and M. catarrhalis. The fu AUC(0-24)/MIC ratios were high (>90% were >200), and none of the pharmacokinetic-pharmacodynamic exposure measurements indexed to the MIC or other factors were significant predictors of clinical or bacteriologic response. Garenoxacin clearance was primarily related to creatinine clearance and ideal body weight. Although garenoxacin exposure was approximately 25% higher for patients with moderate renal dysfunction, this increase does not appear to be clinically significant as exposures in this patient population were not significant predictors of AE occurrence. Garenoxacin exposures were at the upper end of the exposure-response curves for measurements of antimicrobial activity, suggesting that 400 mg of garenoxacin once daily is a safe and adequate dose for the treatment of the specified community-acquired respiratory tract infections.     

Stressors and counseling needs of undergraduate nursing students in Ibadan, Nigeria

Existing evidence suggests that nursing students have high levels of stress and that counseling and other support services should be made available to them. However, the stressors and counseling needs of undergraduate nursing students in Nigeria have yet to be explored. This study used a questionnaire to investigate the stressors, counseling needs, and desired counseling facilities of undergraduate nursing students at the University of Ibadan. Common stressors included excessive schoolwork, financial problems, inadequate recreational facilities, and overcrowded accommodations. There was an association between reporting inconsiderate, insensitive lecturers as stressors and evidence of psychological distress. Nearly 60% of the respondents felt counseling would help them, and most desired counseling for academics, finances, and relationships. Most (78%) of the respondents preferred an independent facility with trained counselors. Desired characteristics for the services included accessibility, affordability, confidentiality, and a friendly atmosphere. Educators and administrators should use this information to design counseling facilities for students.     

Numerical models for the determination of primary structural barriers for diagnostic x-ray facilities

In this work, numerical models are presented for the determination of additional shielding requirements apart from that afforded by patient and hardware devices (grid, cassette, cassette holder, and x-ray table) for diagnostic x-ray primary beams. The models provide an opportunity for the incorporation of appropriate transmission factors obtained by integration of incident radiation energy distribution and workload spectra for clinically realistic condition of varying thicknesses of patient. It was found that as a result of significant differences in the attenuation and hardening properties of water (which was used to represent patient) and lead, lead exposure attenuation equivalent thicknesses do not transmit beam of equivalent penetrating power (though of equivalent exposure) as corresponding patient thicknesses. Sample results are presented which show that ignoring these significant differences will result in underestimation of shielding afforded by patient and hardware devices in practice; thus installing in addition more thickness of lead than necessary. For different incident beam qualities (kVp), obtaining exposure attenuation equivalence of varying thicknesses of patients and hardware in terms of lead is a nontrivial phenomenon.     

Dietary macronutrients modulate hypertrophy and contractility of the detrusor in an experimental model of bladder obstruction

Objectives

To investigate the effects of various diets on structure and function of the bladder in both normal and obstructed bladders of male Wistar rats.

Direct observation therapy-highly active antiretroviral therapy in a resource-limited setting: the use of community treatment support can be effective

This study examines the use of various direct observation therapy-HAART treatment support modalities in Jos, Nigeria. A 12-month observational study enrolling 175 antiretroviral na?ve patients into four arms of direct observation therapy-HAART (highly active antiretroviral therapy); daily observed therapy (DOT), twice weekly observed therapy (TWOT), weekly observed therapy (WOT) and self-administered therapy (SAT), examined community treatment support using family and community members. Treatment outcomes were much better in the treatment-supported groups compared with the control self-therapy group. CD4 cell increases were 218/microL (DOT), 267/microL (TWOT), 205/microL (WOT) versus 224/microL (SAT), whereas plasma HIV-1 RNA reached undetectable levels (<400 copies/mL) in 91%, 88%, 84% versus 79% of patients in the DOT, TWOT, WOT versus SAT groups, respectively, at 48 weeks. We, therefore, strongly support the use of treatment support in our settings.     

A simple dose regimen of artesunate and amodiaquine based on age or body weight range for uncomplicated falciparum malaria in children: comparison of therapeutic efficacy with standard dose regimen of artesunate and amodiaquine and artemether-lumefantrine

A new dose regimen of artesunate and amodiaquine (NDRAA) based on age or body weight range was compared with standard dose regimen of artesunate and amodiaquine (SDRAA) calculated according to body weight and with fixed-dose artesunate-amodiaquine (FDAA) and artemether-lumefantrine (AL) in 304 children afflicted by malaria aged 15 years or younger. In initial comparison (n = 208), children on NDRAA received 1-3 times amodiaquine per kilogram of body weight and 1-1.5 times of artesunate per kilogram of body weight compared with those receiving SDRAA. Parasite but not fever clearance was significantly faster in children who received NDRAA (19.4 ± 8.4 hours vs. 24.6 ± 15.5 hours, P = 0.003). Polymerase chain reaction-uncorrected cure rates on days 28-42 were also significantly higher in children who received NDRAA (P < 0.02 in all cases). Therapeutic responses in children younger than 5 years (n = 96) treated with NDRAA, FDAA, and AL were similar. Changes in hematocrit values and reported adverse events after commencing therapy were similar in those who received NDRAA and SDRAA. All drug regimens were well tolerated. NDRAA based on age or body weight range is simple, is therapeutically superior to SDRAA calculated according to body weight, and is as efficacious as AL in children younger than 5 years.     

Phase II trial of continuous once-daily dosing of sunitinib as first-line treatment in patients with metastatic renal cell carcinoma

BACKGROUND:

Sunitinib at 50 mg/day on the 4‐weeks‐on‐2‐weeks‐off schedule is the current approved regimen for advanced/metastatic renal cell carcinoma (mRCC). Escudier et al reported that continuous, once‐daily dosing with sunitinib 37.5 mg had a manageable safety profile and significant antitumor activity as second‐line mRCC therapy. In this prospective, multicenter, phase II study, we evaluated the activity of continuous once‐daily dosing with sunitinib 37.5 mg as first‐line mRCC treatment.

METHODS:

One hundred nineteen treatment‐naive patients with measurable mRCC received sunitinib. The primary endpoint was objective response; secondary endpoints included progression‐free survival (PFS), safety, pharmacokinetic measurements, exploration of response biomarkers, and patient reported outcomes (PRO).

RESULTS:

Objective response rate (ORR) was 35.3%; median response duration was 10.4 months; 36% of patients had stable disease ≥12 weeks. Median PFS at 1 year was 9 months, and 1‐year survival probability was 67.8%. The most common any‐grade treatment‐related adverse events (AEs) were diarrhea (50%) and hand‐foot syndrome (43%); the most common grade 3‐4 treatment‐related AEs were hand‐foot syndrome (13%), neutropenia (11%), and diarrhea (9%). Steady‐state pharmacokinetics were reached within 3 weeks, with no disproportionate accumulation of sunitinib or its active metabolite throughout the study. No significant correlations between trough drug, active metabolite, or soluble protein levels and clinical response were observed. PRO was largely maintained, although fatigue appeared to worsen after treatment started, with improvement over time.

CONCLUSIONS:

Continuous once‐daily dosing with sunitinib 37.5 mg was active with a manageable safety profile as first‐line mRCC therapy, making this a feasible alternative dosing regimen. Cancer 2012. © 2011 American Cancer Society.     

Activities of artemether-lumefantrine and amodiaquine-sulfalene-pyrimethamine against sexual-stage parasites in falciparum malaria in children

The activities of artemether-lumefantrine and amodiaquine-sulfalene-pyrimethamine against sexual-stage parasites were evaluated in 42 of 181 Nigerian children with uncomplicated Plasmodium falciparum malaria who had gametocytaemia before, during or after treatment with the two combination therapies. The children were randomized to the standard dose regimens. Clinical recovery from illness occurred in all children who carried gametocytes. Gametocytaemia was detected in 20 patients (11%) before treatment and in another 22 patients (12.2%) after treatment. Gametocyte carriage rates were similar in both combination treatment groups, but the area under the curve of gametocytaemia plotted against time was 8-fold higher in the amodiaquine-sulfalene-pyrimethamine-treated than in the artemether-lumefantrine-treated children. The pretreatment gametocyte sex ratio was female biased in both treatment groups. During follow-up, there was a short-lived but significant increase in the gametocyte sex ratio in children treated with amodiaquine-sulfalene-pyrimethamine but not in those treated with artemether-lumefantrine. These results indicate that both combination therapies had moderate effects on gametocyte carriage, but artemether-lumefantrine may be more potent at reducing transmissibility in P. falciparum malaria by exerting greater effects on post-treatment gametocyte density and gametocyte sex ratio.     

Height and risk of heart failure in the Physicians' Health Study

Although previous studies have reported an association between height and cardiovascular disease, it is unclear whether height is associated with the risk of heart failure (HF). We hypothesized that height would be inversely associated with HF risk. We used prospective data from 22,042 male physicians (mean age 53.8 years) from the Physicians' Health Study. Height was self-reported at baseline. Incident HF was ascertained using follow-up questionnaires and validated through review of the medical records in a subsample. The Cox proportional hazard model was used to compute the hazard ratio (HR) and corresponding 95% confidence interval (CI). The mean height ± SD was 1.78 ± 0.07 m. A total of 1,444 HF cases occurred during a mean follow-up of 22.3 years. Compared to subjects in the lowest height category (1.40 to 1.73 m), the HR for HF was 0.86 (95% CI 0.74 to 0.99), 0.82 (95% CI 0.70 to 0.95), and 0.76 (95% CI 0.63 to 0.91) for the height categories of 1.74 to 1.78 m, 1.79 to 1.83 m, and 1.84 to 2.08 m, respectively, after adjustment for age, weight, hypertension, and diabetes mellitus (p for trend = 0.0023). The HR per SD increment in height was 0.92 (95% CI 0.86 to 0.98) in a fully adjusted model. The exclusion of those with prevalent atrial fibrillation, left ventricular hypertrophy, valvular heart disease, and a history of coronary artery bypass grafting yielded similar results (HR per SD 0.88, 95% CI 0.83 to 0.94). In conclusion, our data demonstrated an inverse association between height and incident HF in United States male physicians. Additional studies to elucidate the underlying biologic mechanisms are warranted.