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Biomedical subjects

Abayomi B Ogundele

Publications and source records attributed to Abayomi B Ogundele.

5 recordsLinked to original sources

Inhibition of atazanavir oral absorption by lansoprazole gastric acid suppression in healthy volunteers.

STUDY OBJECTIVE: To determine whether the pharmacokinetics of atazanavir, a protease inhibitor used to treat human immunodeficiency virus (HIV) infection, are altered by its coadministration with lansoprazole, a proton pump inhibitor. DESIGN: Single-dose, open-label, complete-crossover study. SETTING: Clinical research center. SUBJECTS: Ten healthy adult volunteers. MEASUREMENTS AND MAIN RESULTS: In phase A, subjects received a single oral dose of atazanavir 400 mg alone. In phase B, the same subjects received oral lansoprazole 60 mg, and after 24 hours they were given a second dose of oral lansoprazole 60 mg with atazanavir 400 mg. Eleven blood samples were collected from each subject over a 24-hour period for determination of atazanavir plasma concentrations by a validated high-performance liquid chromatography assay. Pharmacokinetic analysis was performed by standard noncompartmental methods. Nine subjects completed the study, and no significant adverse events were reported. Absorption of atazanavir was significantly reduced when it was coadministered with lansoprazole, as evidenced by a 94% decline in mean area under the concentration-time curve during the 24 hours after administration (AUC(0-24)) (p<0.01). The mean +/- SD AUC(0-24) for phase A was 16.3 +/- 9.0 microM x hour versus 0.95 +/- 1.8 microM x hour for phase B (p<0.01). The mean +/- SD maximum concentration of atazanavir was 3.2 +/- 1.7 microM for phase A and 0.13 +/- 0.19 microM for phase B (p<0.01). CONCLUSION: Acid suppression markedly reduced the bioavailability of atazanavir in this group of healthy volunteers. Based on these results, atazanavir should not be coadministered with lansoprazole or other proton pump inhibitors.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Comparative in vitro activities of daptomycin, linezolid, and quinupristin/dalfopristin against Gram-positive bacterial isolates from a large cancer center.

Our objective was to evaluate and compare the in vitro activity of daptomycin, linezolid, and quinupristin/dalfopristin against clinical bloodstream isolates of Gram-positive pathogens from a large cancer center in the Northeastern United States. Minimum inhibitory concentrations (MICs) were determined for daptomycin, quinupristin/dalfopristin, and linezolid against 258 isolates; bactericidal activity was evaluated using time-kill experiments against 14 representative pathogens. Vancomycin-resistant enterococci represented the largest proportion of bacteria tested (32% of the isolates), followed by methicillin-resistant coagulase-negative staphylococci (23%), and vancomycin sensitive enterococci (14%). Against staphylococci, the MIC90 was 1 microg/mL for both daptomycin and quinupristin/dalfopristin and 4 microg/mL for linezolid. Against enterococci, the MIC90 for both daptomycin and linezolid was 4 microg/mL and was 16 microg/mL for quinupristin/dalfopristin. The quinupristin/dalfopristin MIC90 for Enterococcus faecium was 2 microg/mL. Two enterococci were linezolid resistant and remained susceptible to daptomycin. In vitro time-kill studies found daptomycin to be rapidly bactericidal against the majority of organisms tested, killing 99.9% of bacteria within 6 h. Quinupristin/dalfopristin was bactericidal against staphylococci and bacteriostatic against most enterococci. Linezolid was bacteriostatic against all organisms evaluated. Daptomycin, quinupristin/dalfopristin, and linezolid each demonstrated in vitro activity against this collection of organisms. Future clinical studies to evaluate a potential role for these agents in the management of infections in cancer patients, including the treatment of febrile neutropenia, appear warranted.

Acetamides↗

Physical compatibility of pemetrexed disodium with other drugs during simulated Y-site administration.

PURPOSE: The physical compatibility of pemetrexed disodium with selected other drugs during simulated Y-site injection was studied. METHODS: A 5 mL sample of pemetrexed disodium 20 mg/mL in 0.9% sodium chloride injection was combined with 5 mL of a solution of each of 79 other drugs. The other test drugs included antineoplastics, antiinfectives, and supportive care drugs used undiluted or diluted in 0.9% sodium chloride injection or 5% dextrose injection. Visual examinations were performed with the unaided eye in normal diffuse fluorescent light at intervals up to four hours after mixing. Combinations with no obvious incompatibility were examined further with a high-intensity monodirectional light source to enhance visualization of small particles and low-level turbidity. The combinations were also evaluated with a turbidimeter at one and four hours. All combinations without visual incompatibility were assessed with a particle sizer-counter. RESULTS: Of the 79 pemetrexed-secondary drug combinations, 55 were compatible for at least four hours. However,mixture with 24 drugs resulted in precipitation (including microprecipitation) and color change. CONCLUSION: Pemetrexed disodium was incompatible with 24 drugs during simulated Y-site administration and should not be administered with them.

Antineoplastic Agents↗

Using medium-fill simulation to establish a benchmark microbiological contamination rate for low-risk-level compounding.

A benchmark contamination rate for prefilled syringe compounding was determined by using a medium-fill-simulation method. One thousand thirty-five 1-mL tuberculin syringes were aseptically filled with 0.9 mL of sterile soybean-casein digest medium and capped. These syringes were placed into clear nonsterile plastic bags and incubated at 35 degrees C for seven days, then inspected for cloudiness or colony formation indicative of bacterial growth. The operation was performed by two certified pharmacy technicians in an ISO Class 5 vertical-airflow biological safety cabinet in a typical inpatient pharmacy compounding area over two days. The technicians wore protective garments and gloves and followed standard procedures of preparing sterile injections. The adequacy of the methodology was verified by using four syringes that contained deliberately contaminated medium and incubating them along with 15 aseptically prepared syringes at 35 degrees C for seven days. Colony formation in the four syringes containing contaminated medium was directly observed and differentiated from the control syringes, which confirms the validity of the method. No bacterial growth was detected in any of the 1035 medium-filled syringes studied. Therefore, the contamination rate for aseptic compounding operation was less than 0.1%. Medium-fill-simulation testing of 1035 prefilled tuberculin syringes yielded no contamination. A contamination rate of less than 0.1% should be achievable and expected for this type of low-risk pharmacy preparation after pharmacies validate their own compounding operation.

Bacteria↗