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Biomedical subjects

D N Fish

Publications and source records attributed to D N Fish.

At least 37 records · Page 2Linked to original sources
PubMed1997

The clinical pharmacokinetics of levofloxacin.

Levofloxacin is a fluoroquinolone antibiotic and is the optical S-(-) isomer of the racemic drug substance ofloxacin. It has a broad spectrum of in vitro activity against Gram-positive and Gram-negative bacteria, as well as certain other pathogens such as Mycoplasma, Chlamydia, Legionella and Mycobacteria spp. Levofloxacin is significantly more active against bacterial pathogens than R-(+)-ofloxacin. Levofloxacin hemihydrate, the commercially formulated product, is 97.6% levofloxacin by weight. Levofloxacin pharmacokinetics are described by a linear 2-compartment open model with first-order elimination. Plasma concentrations in healthy volunteers reach a mean peak drug plasma concentration (Cmax) of approximately 2.8 and 5.2 mg/L within 1 to 2 hours after oral administration of levofloxacin 250 and 500mg tablets, respectively. The bioavailability of oral levofloxacin approaches 100% and is little affected by the administration with food. Oral absorption is very rapid and complete, with little difference in the serum concentration-time profiles following 500mg oral or intravenous (infused over 60 minutes) doses. Single oral doses of levofloxacin 50 to 1000mg produce a mean Cmax and area under the concentration-time curve (AUC) ranging from approximately 0.6 to 9.4 mg/L and 4.7 to 108 mg.h/L, respectively, both increasing linearly in a dose-proportional fashion. The pharmacokinetics of levofloxacin are similar during multiple-dose regimens to those following single doses. Levofloxacin is widely distributed throughout the body, with a mean volume of distribution of 1.1 L/kg, and penetrates well into most body tissues and fluids. Drug concentrations in tissues and fluids are generally greater than those observed in plasma, but penetration into the cerebrospinal fluid is relatively poor (concentrations approximately 16% of simultaneous plasma values). Levofloxacin is approximately 24 to 38% bound to serum plasma proteins (primarily albumin); serum protein binding is independent of serum drug concentrations. The plasma elimination half-life (t1/2 beta) ranges from 6 to 8 hours in individuals with normal renal function. Approximately 80% of levofloxacin is eliminated as unchanged drug in the urine through glomerular filtration and tubular secretion; minimal metabolism occurs with the formation of no metabolites possessing relevant pharmacological activity. Renal clearance and total body clearance are highly correlated with creatinine clearance (CLCR), and dosage adjustments are required in patients with significant renal dysfunction. Levofloxacin pharmacokinetics are not appreciably affected by age, gender or race when differences in renal function, and body mass and composition are taken into account. Important drug interactions exist with aluminium- and magnesium-containing antacids and ferrous sulfate, as with other fluoroquinolones, resulting in significantly decreased levofloxacin absorption when administered concurrently. These agents should be administered at least 2 hours before or after levofloxacin administration. Cimetidine and probenecid decrease levofloxacin renal clearance and increase t1/2 beta; the magnitudes of these interactions are not clinically significant. Levofloxacin appears to have only minor potential for significantly altering the pharmacokinetics of theophylline, warfarin, zidovudine, ranitidine, digoxin or cyclosporin; however, patients receiving these drugs concurrently should be monitored closely for signs of enhanced pharmacological effect or toxicity. Levofloxacin pharmacokinetics are not significantly altered by sucralfate when administration of these drugs is separated by at least 2 hours.

Anti-Infective Agents↗
PubMed1995

Safety and cost of rapid i.v. injection of famotidine in critically ill patients.

The safety and cost of famotidine in intensive care patients given the drug by rapid i.v. injection or slow i.v. infusion were studied. All patients admitted to the medical-coronary care and surgical intensive care units (ICUs) at a university teaching hospital over a two-month period who had orders for at least one dose of famotidine injection for any indication were randomly assigned to receive the drug by rapid i.v. injection or slow i.v. infusion via volumetric chamber. Data on patient demographics, drug administration time, adverse effects, cardiovascular variables, and costs (including drug acquisition, supply, and nursing personnel costs) were collected prospectively. Fifty-three patients received famotidine by i.v. injection (a total of 1041 doses) and 52 by i.v. infusion (1006 doses). The mean +/- S.D. duration of famotidine administration was 44 +/- 12 seconds in the i.v.-injection group and 19 +/- 5 minutes in the i.v.-infusion group. Adverse effects possibly related to famotidine occurred in three injection-group patients and two infusion-group patients. No significant difference between the groups in cardiovascular variables (mean arterial pressure, heart rate, and respiratory rate) was noted. Cost savings for the injection group relative to the infusion group totaled $2886 for the two-month study period. Half of the savings came from reduced supply costs and half from reduced personnel costs. The annualized savings to the institution would be about $17,300. Rapid i.v. injection of famotidine appeared to be as safe in ICU patients as giving the drug by slow i.v. infusion and was less costly.

Costs and Cost Analysis↗
PubMed1994

Penetration of clarithromycin into lung tissues from patients undergoing lung resection.

The concentrations of clarithromycin and its active principal metabolite, 14-(R)-hydroxy-clarithromycin, were determined in lung tissue obtained during lung resection and compared with concomitant concentrations in plasma. Concentrations of the parent and metabolite were determined by high-performance liquid chromatography. The 15 patients studied were given 500 mg orally every 12 h for a minimum of five doses to achieve steady-state concentrations. The mean concentrations of clarithromycin and 14-(R)-hydroxy-clarithromycin in plasma just prior to the final dose were 1.38 and 0.67 micrograms/ml, respectively, and those 4 h after the final dose (at the time of lung resection) were 1.89 and 0.80 microgram/mL, respectively. The concentrations of the parent and metabolite in lung tissue at the time of lung resection averaged 54.3 and 5.12 micrograms/g, respectively, with a mean calculated ratio of concentrations of the parent to metabolite being 11.3 in lung tissue and 2.4 in plasma. Clarithromycin and its active metabolite are extensively distributed into human lung tissue.

Adolescent↗
PubMed1993

Applicability of the Greulich and Pyle skeletal age standards to black and white children of today.

OBJECTIVE: The Greulich and Pyle skeletal age atlas was derived from white children of upper socioeconomic level during the 1930s. To our knowledge, the Greulich and Pyle standards have not been reassessed for both black and white children; it was the purpose of this study to reassess the applicability of these standards to today's children. DESIGN: A "blinded" review of hand roentgenograms taken for the evaluation of trauma was performed. Age of the subjects was evenly distributed between 0 and 18 years. The roentgenograms were scored for bone age by five individuals from different disciplines and levels of training. The difference between the median bone age and the child's chronologic age was calculated for each roentgenogram and stratified into four age groups: early childhood (0 to 4 years), middle childhood (4 to 8 years), late childhood (8 to 13 years), and adolescence (13 to 18 years). SETTING: The roentgenograms were obtained from four hospital emergency rooms in the Lake Erie basin area, the same geographic area from which the Greulich and Pyle standards originated. PATIENTS: There were 841 children: 452 boys and 389 girls, 461 black and 380 white children. RESULTS: The bone ages and chronologic ages were similar for white girls of all ages. Black girls were skeletally advanced by 0.4 to 0.7 year (P < .001), except during middle childhood. White boys were skeletally delayed during middle childhood by 0.9 year (P < .001) and during late childhood by 0.4 year (P < .01), but they were advanced during the adolescent years by 0.5 year (P < .01). Black boys showed no difference except for the adolescent group, which was skeletally advanced by 0.4 year (P < .02). CONCLUSIONS: The Greulich and Pyle atlas is not applicable to all children today, especially black girls. We should be aware of this information when making clinical decisions requiring accurate bone ages.

Adolescent↗
PubMed1993

Hand manifestations of oxalosis.

Oxalosis is an unusual metabolic disease that results either from an inherited hepatic enzyme deficiency or as the result of poor oxalate clearance during chronic hemodialysis. We present two cases of oxalosis and describe the hand manifestations of this condition and their treatment. One patient had painful, progressive gangrene, whereas in the other the disease took an indolent course with small palmar crystalline deposits.

Adult↗
PubMed1993

Pull-out strength of five suture anchors.

Five commercially available suture anchor devices were tested to failure in human cadaveric proximal tibiae. A total of 198 trials were completed. Insertion was uncomplicated for all anchors, with the exception of the Acufex Rod TAG device, with five of 22 (23%) of these breaking upon insertion into thicker cortical bone. Overall, the anchors performed significantly (p < 0.05) better when placed in thicker cortical bone, further away from the joint surface, and when loaded in a direction parallel to the bone surface. The Mitek GII anchor failed (pulled out of bone) less often than the other anchors (19% vs. 46%). In loading perpendicular to the bone surface, the Mitek GII and Statak were the strongest (p < 0.05), with mean loads at failure of 82.5 and 90.2 N, respectively. The Acufex Rod TAG, Acufex Wedge TAG, and Mitek GI failed at 67.2, 65.5, and 49.4 N respectively.

Aged↗
PubMed1993

Prophylaxis of HIV infection following occupational exposure.

OBJECTIVE: To review the risk of HIV infection following occupational exposure, the theoretical basis for chemoprophylaxis, investigative experience with chemoprophylaxis in animals and humans, and the economic aspects of postexposure chemoprophylaxis. DATA SOURCES: English-language articles and conference proceedings pertaining to the risk of occupational HIV infection and to postexposure chemoprophylaxis. STUDY SELECTION: Studies evaluating chemoprophylaxis of HIV infection following occupational exposure were selected for review. Abstracts reporting ongoing clinical trials were also included. DATA EXTRACTION: In vitro studies are discussed to provide the immunologic rationale for chemoprophylaxis. Animal studies examining the efficacy of chemoprophylaxis in preventing non-HIV retroviral infection are reviewed, and their applicability to human HIV infection is critically evaluated. Human studies and case reports describing attempts at chemoprophylaxis of HIV infection following occupational exposure are discussed. DATA SYNTHESIS: Chemoprophylaxis of HIV infection following occupational exposure has focused on the use of zidovudine (ZDV) because it was previously the only antiretroviral agent approved for treating HIV infection. Animal models of retroviral infection provide conflicting data regarding the efficacy of ZDV chemoprophylaxis, and there are important questions about the applicability of animal data to human HIV infection because of differences in natural histories of non-HIV retroviral infections, inoculum size, dosing of ZDV, and routes of infection. Human surveillance studies are thus far inadequate to determine the efficacy of ZDV prophylaxis because of the very low HIV seroconversion rates following occupational exposure. ZDV is well tolerated during short-term administration in people without HIV infection, but long-term safety is unknown. In addition, the true cost-benefit ratio of ZDV chemoprophylaxis is uncertain. CONCLUSIONS: Current data from in vitro, animal, and human studies are inadequate to define the appropriate role of ZDV in preventing HIV infection following occupational exposure. Limited toxicity data and the high cost of treatment must be weighed against the theoretical benefits of ZDV use in this setting. The decision to employ ZDV for postexposure prophylaxis must ultimately be based on existing institutional policies, the attitude of the responsible physician regarding such practice, and/or the desires of the exposed healthcare worker after being properly informed of potential risks and benefits.

Animals↗
PubMed1992

Antibiotic-impregnated cement use in U.S. hospitals.

The results of a survey of the use of antibiotic-impregnated bone cement and cement beads in U.S. hospitals are reported. A random sample of hospitals was selected from all hospitals registered with the American Hospital Association. A questionnaire designed to characterize the extent of use of the products and the degree of pharmacy involvement was mailed to the pharmacy directors at 547 hospitals nationwide. The response rate was 61.7% (336 evaluable returns). Ninety hospitals (26.9%) reported using antibiotic-impregnated bone cement or cement beads. Product use was significantly greater in urban hospitals, hospitals larger than 200 beds, teaching hospitals, and hospitals with pharmaceutical services in the operating rooms. Most facilities using the products were community hospitals. Total hip arthroplasty, total knee arthroplasty, and chronic osteomyelitis were the most common indications for use. Systemic antibiotics were also administered in the great majority of hospitals reporting use of the products. The products were generally used in fewer than one procedure per month. Aminoglycosides and various cephalosporins were the antibiotics most commonly used; most have not been adequately studied for this use. Although nearly all the hospital pharmacies purchased antibiotics for these products, none mixed cement and only two premanufactured antibiotic beads. About one fourth of the hospitals surveyed reported using antibiotic-impregnated bone cement and cement beads, although the total number of patients being treated was small.

Anti-Bacterial Agents↗
PubMed1991

Treatment of delirium in the critically ill patient.

The clinical use of neuroleptics, benzodiazepines, narcotic analgesics, barbiturates, and neuromuscular blockers to manage delirium and agitation in the intensive-care setting is reviewed. Delirium is the most commonly encountered mental disturbance in critically ill patients and may be precipitated by factors such as physical illness, medications, pain, and emotional stress. If agitation cannot be controlled through nonpharmacologic means, pharmacologic intervention may be necessary. Haloperidol is the neuroleptic of choice for rapid control of delirium and agitation in the critically ill patient. It has few adverse effects in most patients, even at high doses, although it can cause extrapyramidal symptoms. Among the benzodiazepines, lorazepam should be considered a first-line agent. It may be used alone or in combination with haloperidol (or another neuroleptic). Midazolam is suitable for administration by continuous i.v. infusion in the intensive-care setting because of its water solubility, short half-life, and short duration of action. The sedative effects of narcotics may be advantageous in patients with both agitation and pain. Barbiturates are not recommended for routine use in the treatment of delirium and agitation. The use of neuromuscular blocking agents such as pancuronium bromide and metocurine iodide may be necessary when other therapies have failed. Haloperidol and the benzodiazepines, alone or in combination, are the drugs of choice for treatment of acute agitation and delirium in critically ill patients.

Anti-Anxiety Agents↗
PubMedDate not supplied

Current practice in use of prereduction traction for congenital dislocation of the hip.

To define the current application of preliminary traction for congenital dislocation of the hip (CDH), 335 members of the Pediatric Orthopaedic Society were surveyed, with an 87% response rate. Most respondents believe that traction reduces the incidence of avascular necrosis (AVN) and enables easier reduction. Only 5% of those surveyed do not use traction, but it is used more frequently in the Northeastern United States. Home traction, favored by 31% of the respondents, is used longer than hospital traction. Although traction is commonly used, a consensus to use preliminary traction has not been achieved. Practice patterns should not be used to determine effectiveness of a treatment.

Canada↗
PubMedDate not supplied

Cidofovir.

Explore the source record for details and available documents.

Anti-HIV Agents↗
PubMedDate not supplied

Variable disposition of ciprofloxacin in critically ill patients undergoing continuous arteriovenous hemodiafiltration.

Continuous arteriovenous hemodiafiltration (CAVHD) is being used increasingly in critically ill patients with acute renal failure (ARF). We prospectively evaluated extracorporeal and total systemic clearances (ClCAVHD and Cls) of ciprofloxacin during CAVHD in four patients with severe ARF to assess the adequacy of drug dosing. Ciprofloxacin serum and ultrafiltrate concentrations were measured by high-performance liquid chromatography. The ClCAVHD accounted for approximately 5.9% (range 2.8-11.6%) of Cls of ciprofloxacin. However, large variability in serum concentrations was observed with the normally recommended dose of 400 mg/day, and doses of up to 800 mg/day were required to maintain concentrations suitable for treatment of serious infections. High daily doses of ciprofloxacin required in these patients are likely related to altered pharmacokinetics in serious illness as well as to the increased extracorporeal clearance during CAVHD. Clinical studies to define appropriate dosing recommendations for ciprofloxacin during CAVHD are necessary to guide clinicians in optimum drug use.

Acute Kidney Injury↗