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Biomedical subjects

J M DeVito

Publications and source records attributed to J M DeVito.

10 recordsLinked to original sources
PubMed1993

Bioequivalence of oral and injectable levoleucovorin and leucovorin.

The bioequivalence and bioavailability of oral and intravenous formulations of levoleucovorin and leucovorin were studied, and the absolute bioavailabilities of levoleucovorin and leucovorin tablet formulations were determined. Healthy male volunteers participated in two randomized, single-dose, four-way crossover studies. The treatment groups were as follows: A = five 2.5-mg levoleucovorin tablets, B = five 5-mg leucovorin tablets, C = one 12.5-mg levoleucovorin tablet, D = one 25-mg leucovorin tablet, in study 1; A = 15-mg levoleucovorin injection, B = two 7.5-mg levoleucovorin tablets, C = 30-mg leucovorin injection, D = two 15-mg leucovorin tablets, in study 2. Serum concentrations of N-5-methyltetrahydrofolate (the primary metabolite and circulating form of reduced folate after leucovorin administration) and total tetrahydrofolate were measured over 24 hours after dose administration. Pharmacokinetic values were calculated for N-5-methyltetrahydrofolate and total tetrahydrofolates; values were compared for A versus B, C versus D, A versus C, and B versus D in study 1 and A versus C and B versus D in study 2. Results from 35 men in study 1 and 33 in study 2 showed that 12.5-mg oral doses and 15-mg intravenous doses of levoleucovorin are bioequivalent to 25-mg oral doses and 30-mg intravenous doses of leucovorin, respectively. Equivalence was observed after oral and intravenous administration. The absolute bioavailability of levoleucovorin (74%) was not significantly different from that of leucovorin (65%).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1987

Oral ciprofloxacin in the treatment of serious soft tissue and bone infections. Efficacy, safety, and pharmacokinetics.

Forty-eight patients were enrolled in a clinical study of oral ciprofloxacin for the treatment of soft tissue or bone infections. Patients received 500 to 750 mg of ciprofloxacin every 12 hours. In the predominantly older population studied, there were 13 patients with osteomyelitis, 24 diabetic patients with soft tissue infection and probable osteomyelitis, and 11 patients with other soft tissue infections. Infecting pathogens included Pseudomonas aeruginosa in 25 patients, Serratia species in nine patients, Staphylococcus aureus in 13 patients, and other aerobic gram-negative rods in 21 patients. Clinical response (defined as resolution or improvement) was noted in 84 percent of patients with non-diabetic osteomyelitis, in 79 percent of patients with diabetic infections, and in 91 percent of patients with soft tissue infections. Microbiologic outcome was very favorable in 75 percent of cases, and Pseudomonas responded as well as any other pathogen. Pharmacokinetic properties of ciprofloxacin were evaluated in 12 patients, and the data were analyzed using both compartmental and non-compartmental analyses. Mean values for compartmental rate constants (hours-1) were as follows: absorption rate constant = 1.15; intercompartmental rate constants, k12 = 0.48, and k21 = 0.58; elimination rate constant = 0.46; distribution rate constant = 1.31; and terminal elimination rate constant = 0.19. The apparent volume of distribution at steady state/bioavailability was 196 liters and total body clearance/bioavailability was 45.9 liters/hour. The mean time to peak concentration was 1.3 hours. The mean peak concentration as determined by compartmental fitting (2.4 micrograms/ml) underestimated the observed peak (3.2 micrograms/ml) by 24.8 percent. Clearance of ciprofloxacin was similar regardless of the method used to fit the data, whereas the volume of distribution was significantly different when the two analysis techniques were compared. Ciprofloxacin was well tolerated, with the most frequent adverse reactions being rash, gastrointestinal intolerance, and increased levels of liver enzymes, each of which occurred in five patients.

Administration, Oral↗
PubMed1987

Effect of multiple dose oral ciprofloxacin on the pharmacokinetics of theophylline and indocyanine green.

Interaction between ciprofloxacin and theophylline was studied in eight male volunteers, who were randomly divided into two groups. All subjects were given intravenous theophylline and indocyanine green (ICG) on study days 0, 7 and 14. Group I subjects received ciprofloxacin 750 mg orally every 12 h on days 1-7. Group II subjects received ciprofloxacin 750 mg every 12 h on days 6-14. No significant changes in ICG clearance or half-life were noted. A significant increase in theophylline half-life and volume of distribution was observed (P less than 0.05); however, clearance was not significantly decreased (P = 0.1). A potentially clinically significant interaction was detected in three subjects whose theophylline clearance decreased by 42-113%. Until further clinical experience is gained, we advise caution when these agents are coadministered. Some adjustment in theophylline dosage may be required; therefore, these patients should have serum theophylline concentration measurements and careful clinical assessment for theophylline toxicity.

Administration, Oral↗
PubMed1987

Lack of apparent effect of assay methodology on the pharmacokinetics of digoxin.

The purpose of this study was to determine if serum digoxin concentration data using three different automated immunoassay methods would produce similar pharmacokinetic values in normal volunteer subjects. Area under the curve (AUC), steady-state volume of distribution/bioavailability ratio (Vd/F), terminal elimination rate constant (beta), clearance/bioavailability ratio (CL/F), maximum digoxin concentration (Cmax), minimum digoxin concentration (Cmin), and time of peak (Tp) were evaluated. Ten healthy volunteers received digoxin capsules 0.2 mg daily for 10 days. On day 10, 16 serial blood samples were collected over a 24-h dosing interval and analyzed by radioimmunoassay (RIA) (Concept 4, Micromedic Systems), fluorescence polarization immunoassay (FPIA) (TDx, Abbott Laboratories), and affinity column-mediated immunoassay (ACMIA), (aca, duPont Instruments). When comparing RIA and FPIA, the mean of the percent differences for AUC, Vd/F, beta, and CL/F were 9, 4, 10, and 6%, respectively. The mean of the percent differences were 2, 3, 44, and 6%, respectively, when comparing RIA and ACMIA. However, none of these differences were statistically significant. Although a trend toward higher Cmax values by RIA was noted, there was no statistical difference in Cmax, Cmin, and Tp. Orthogonal regression of all serum digoxin concentrations showed that FPIA = 0.76 RIA + 0.19, r = 0.967 (p less than 0.001); and ACMIA = 0.92 RIA + 0.04, r = 0.943 (p less than 0.001). At serum digoxin concentrations less than 1 ng/ml, FPIA overestimated RIA results (p less than 0.005), while ACMIA was approximately equal to the RIA results.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Proteins↗
PubMed1987

Ciprofloxacin and norfloxacin, two fluoroquinolone antimicrobials.

The chemistry, mechanism of action, antimicrobial spectrum, pharmacokinetics, clinical efficacy, adverse effects, and dosage and administration of ciprofloxacin and norfloxacin are reviewed, and mechanisms of antimicrobial resistance and drug and laboratory interactions are described. Norfloxacin is the first antimicrobial in the fluoroquinolone class to be marketed in the United States; ciprofloxacin is under investigation in clinical trials. The fluoroquinolones are structurally related to nalidixic acid. The activity and spectrum are enhanced by the addition of 6-fluoro and 7-piperazino substituents. Quinolone antimicrobials appear to inhibit DNA gyrase, an enzyme specific and essential for all bacteria, as their primary mechanism of action. As a result, DNA synthesis is inhibited. Ciprofloxacin and norfloxacin are active against gram-negative enteric bacteria, Pseudomonas aeruginosa, Haemophilus influenzae, and Neisseria gonorrhoeae. Ciprofloxacin has good activity against Staphylcoccus spp., including methicillin-resistant Staph. aureus. Norfloxacin generally is less potent than ciprofloxacin, particularly against Ps. aeruginosa and Staph. aureus. Peak concentrations occur about one to two hours after an oral administration of either drug. Both drugs are widely distributed in body fluids and tissues and are eliminated by renal excretion, metabolism, and biliary excretion. Dosage reductions are required in severe renal dysfunction. Ciprofloxacin and norfloxacin are effective agents for treating urinary-tract infections, including infections caused by Ps. aeruginosa. The recommended dosage of norfloxacin for urinary-tract infections in adults is 400 mg orally every 12 hours; the drug should be given for 7 to 10 days in uncomplicated infections and for 10 to 21 days in complicated ones. The fluoroquinolones may be useful for treating chronic bacterial prostatitis. Ciprofloxacin is potentially useful for treating sexually transmitted diseases. Ciprofloxacin is active against N. gonorrhoeae, including beta-lactamase-producing strains and strains that are resistant to tetracycline, and Chlamydia spp. Use of ciprofloxacin for treating gastrointestinal infections and for selective decontamination of the gastrointestinal tract is promising. In open studies, ciprofloxacin has been effective against a variety of infections caused by susceptible organisms. Resistance to ciprofloxacin has developed during treatment of infections caused by Ps. aeruginosa, Staph. aureus, and Serratia marcescens. The most frequently reported adverse effects of either drug are gastrointestinal complaints, headache, and dizziness.(ABSTRACT TRUNCATED AT 400 WORDS)

Ciprofloxacin↗
PubMed1986

In vitro evaluation of nasogastric administration methods for phenytoin.

The effect on phenytoin recovery of various methods of nasogastric administration of phenytoin suspension was studied. Phenytoin acid suspension 4 mL (100 mg) was administered through a nasogastric (NG) tube using 10 methods designed to simulate clinical situations. The suspension was given either undiluted or diluted, with or without irrigation of the NG tube. Solutions of 5% dextrose injection, 0.9% sodium chloride injection, sterile water for irrigation, and lactated Ringer's injection were used as diluents or irrigants. After each administration, 40 mL of air was forced through the NG tube to expel any remaining suspension. Phenytoin concentration was assayed by high-performance liquid chromatography before and after administration through the NG tube. In the method that used no diluent or irrigation, 75.5 +/- 5.3% of the initial dose volume was lost, significantly more loss than with any of the other methods. The mean dose volume lost for all of the other nine methods was 6.4 +/- 3.4%. The type of fluid used for dilution or irrigation had little influence on phenytoin recovery. Until other methods can be evaluated, phenytoin suspension should be diluted and irrigated with at least 20 mL of fluid when given by nasogastric tube. Evacuation of the tube with 40 mL of air after phenytoin administration is also recommended.

Humans↗
PubMed1985

Effect of formulary restriction of cefotaxime usage.

Cefotaxime sodium was assigned to the open formulary for 12 months and then was placed on formulary restriction to evaluate the restriction's effect on rate of use by services and appropriateness of use. Over 18 months, 187 cases (72 before and 115 after restriction) were reviewed. The majority of use (prerestriction and postrestriction) was in the medicine, pediatrics, and surgery services. The postrestriction usage rate for the three services increased significantly. Cefotaxime was used appropriately in 85% of cases during both periods and was not used prophylactically. Appropriateness of use was independent of formulary restriction. During both periods, approximately 76% of patients received cefotaxime for pneumonia, sepsis, meningitis, or immunosuppression. Of 205 infections, gram-negative bacilli accounted for over half of the pathogens isolated. Thus, formulary restriction was ineffective in reducing the rate of cefotaxime usage and had no effect on the appropriateness of usage.

Adolescent↗