Gender and asthma-chronic obstructive pulmonary disease overlap syndrome

OBJECTIVE

To assess relationships between obstructive lung diseases, respiratory symptoms, and comorbidities by gender.

METHODS

Data from 12 594 adult respondents to the 2012 South Carolina Behavioral Risk Factor Surveillance System telephone survey were used. Five categories of chronic obstructive airway disease (OAD) were defined: former asthma only, current asthma only, chronic obstructive pulmonary disease (COPD) only, asthma-COPD overlap syndrome (ACOS), and none. Associations of these categories with respiratory symptoms (frequent productive cough, shortness of breath, and impaired physical activities due to breathing problems), overall health, and comorbidities were assessed using multivariable logistic regression for men and women.

RESULTS

Overall, 16.2% of men and 18.7% of women reported a physician diagnosis of COPD and/or asthma. Former asthma only was higher among men than women (4.9% vs. 3.2%, t-test p = 0.008). Current asthma only was more prevalent among women than men (7.2% vs. 4.7%, p < 0.001), as was ACOS (4.0% vs. 2.2%, p < 0.001). Having COPD only did not differ between women (4.3%) and men (4.4%). Adults with ACOS were most likely to report the 3 respiratory symptoms. COPD only and ACOS were associated with higher likelihoods of poor health and most comorbidities for men and women. Current asthma only was also associated with these outcomes among women, but not among men.

CONCLUSIONS

In this large population-based sample, women were more likely than men to report ACOS and current asthma, but not COPD alone. Gender differences were evident between the OAD groups in sociodemographic characteristics, respiratory symptoms, and comorbidities, as well as overall health.

Targeting Persons With or At High Risk for Chronic Obstructive Pulmonary Disease by State-based Surveillance

The Behavioral Risk Factor Surveillance System (BRFSS) survey is used to estimate chronic obstructive pulmonary disease (COPD) prevalence and could be expanded to describe respiratory symptoms in the general population and to characterize persons with or at high risk for the disease. Tobacco duration and respiratory symptom questions were added to the 2012 South Carolina BRFSS. Data concerning sociodemographics, chronic illnesses, health behaviors, and respiratory symptoms were collected in 9438 adults ≥ 35 years-old. Respondents were categorized as having COPD, high risk, or low risk for the disease. High risk was defined as no self-reported COPD, ≥ 10 years' tobacco use, and ≥ 1 respiratory symptom (frequent productive cough or shortness of breath (SOB), or breathing problems affecting activities). Prevalence of self-reported and high-risk COPD were 9.1% and 8.0%, respectively. Overall, 17.3%, 10.6%, and 5.2% of all respondents reported activities limited by breathing problems, frequent productive cough, and frequent SOB, respectively. The high-risk group was more likely than the COPD group to report a productive cough and breathing problems limiting activities as well as being current smokers, male, and African-American. Health impairment was more severe in the COPD than the high-risk group, and both were worse than the low-risk group.

CONCLUSIONS

Persons at high risk for COPD share many, but not all, of the characteristics of persons diagnosed with the disease. Additional questions addressing smoking duration and respiratory symptoms in the BRFSS identifies groups at high risk for having or developing COPD who may benefit from smoking cessation and case-finding interventions.

Smoking duration, respiratory symptoms, and COPD in adults aged ≥45 years with a smoking history

BACKGROUND

The purpose of this study was to assess the relationship of smoking duration with respiratory symptoms and history of chronic obstructive pulmonary disease (COPD) in the South Carolina Behavioral Risk Factor Surveillance System survey in 2012.

METHODS

Data from 4,135 adults aged ≥45 years with a smoking history were analyzed using multivariable logistic regression that accounted for sex, age, race/ethnicity, education, and current smoking status, as well as the complex sampling design.

RESULTS

The distribution of smoking duration ranged from 19.2% (1-9 years) to 36.2% (≥30 years). Among 1,454 respondents who had smoked for ≥30 years, 58.3% were current smokers, 25.0% had frequent productive cough, 11.2% had frequent shortness of breath, 16.7% strongly agreed that shortness of breath affected physical activity, and 25.6% had been diagnosed with COPD. Prevalence of COPD and each respiratory symptom was lower among former smokers who quit ≥10 years earlier compared with current smokers. Smoking duration had a linear relationship with COPD (P<0.001) and all three respiratory symptoms (P<0.001) after adjusting for smoking status and other covariates. While COPD prevalence increased with prolonged smoking duration in both men and women, women had a higher age-adjusted prevalence of COPD in the 1-9 years, 20-29 years, and ≥30 years duration periods.

CONCLUSION

These state population data confirm that prolonged tobacco use is associated with respiratory symptoms and COPD after controlling for current smoking behavior.

Body mass index, respiratory conditions, asthma, and chronic obstructive pulmonary disease

BACKGROUND

This study aims to assess the relationship of body mass index (BMI) status with respiratory conditions, asthma, and chronic obstructive pulmonary disease (COPD) in a state population.

METHODS

Self-reported data from 11,868 adults aged ≥18 years in the 2012 South Carolina Behavioral Risk Factor Surveillance System telephone survey were analyzed using multivariable logistic regression that accounted for the complex sampling design and adjusted for sex, age, race/ethnicity, education, smoking status, physical inactivity, and cancer history.

RESULTS

The distribution of BMI (kg/m(2)) was 1.5% for underweight (<18.5), 32.3% for normal weight (18.5-24.9), 34.6% for overweight (25.0-29.9), 26.5% for obese (30.0-39.9), and 5.1% for morbidly obese (≥40.0). Among respondents, 10.0% had frequent productive cough, 4.3% had frequent shortness of breath (SOB), 7.3% strongly agreed that SOB affected physical activity, 8.4% had current asthma, and 7.4% had COPD. Adults at extremes of body weight were more likely to report having asthma or COPD, and to report respiratory conditions. Age-adjusted U-shaped relationships of BMI categories with current asthma and strongly agreeing that SOB affected physical activity, but not U-shaped relationship with COPD, persisted after controlling for the covariates (p < 0.001). Morbidly obese but not underweight or obese respondents were significantly more likely to have frequent productive cough and frequent SOB than normal weight adults after adjustment.

CONCLUSION

Our data confirm that both underweight and obesity are associated with current asthma and obesity with COPD. Increased emphasis on exercise and nutrition may improve respiratory conditions.

Role of the fixed combination of fluticasone and salmeterol in adult Chinese patients with asthma and COPD

Chronic obstructive pulmonary disease (COPD) and asthma are common airway disorders characterized by chronic airway inflammation and airflow obstruction, and are a leading cause of morbidity and mortality in the People's Republic of China. These two diseases pose a high economic burden on the family and the whole of society. Despite evidence-based Global Initiative for Chronic Obstructive Lung Disease and Global Initiative for Asthma guidelines being available for the diagnosis and management of COPD and asthma, many of these patients are not properly diagnosed or managed in the People's Republic of China. The value of combination therapy with inhaled corticosteroids and long-acting β2-agonists has been established in the management of asthma and COPD globally. Combinations of inhaled corticosteroids and long-acting β2-agonists such as fluticasone and salmeterol, have been shown to be effective for improving symptoms, health status, and reducing exacerbations in both diseases. In this review, we discuss the efficacy and safety of this combination therapy from key studies, particularly in the People's Republic of China.

Chronic obstructive pulmonary disease and asthma-patient characteristics and health impairment

Abstract Background: Persons with chronic obstructive pulmonary disease (COPD) and/or asthma have great risk for morbidity. There has been sparse state-specific surveillance data to estimate the impact of COPD or COPD with concomitant asthma (overlap syndrome) on health-related impairment.

METHODS

The North Carolina (NC) Behavioral Risk Factor Surveillance System (BRFSS) was used to assess relationships between COPD and asthma with health impairment indicators. Five categories [COPD, current asthma, former asthma, overlap syndrome, and neither] were defined for 24,073 respondents. Associations of these categories with health impairments (physical or mental disability, use of special equipment, mental or physical distress) and with co-morbidities (diabetes, coronary heart disease, stroke, arthritis, and high blood pressure) were assessed.

RESULTS

Fifteen percent of NC adults reported a COPD and/or asthma history. The overall age-adjusted prevalence of any self-reported COPD and current asthma were 5.6% and 7.6%, respectively; 2.4% reported both. In multivariable analyses, adults with overlap syndrome, current asthma only, and COPD only were twice as likely as those with neither disease to report health impairments (p < 0.05). Compared to those with neither disease, adults with overlap syndrome and COPD were more likely to have co-morbidities (p < 0.05). The prevalence of the five co-morbid conditions was highest in overlap syndrome; comparisons with the other groups were significant (p < 0.05) only for diabetes, stroke, and arthritis.

CONCLUSIONS

The BRFSS demonstrates different levels of health impairment among persons with COPD, asthma, overlap syndrome, and those with neither disease. Persons reporting overlap syndrome had the most impairment and highest prevalence of co-morbidities.

The prevalence, characteristics, and impact of chronic obstructive pulmonary disease in North Carolina

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality. We describe the prevalence, characteristics, and impact of COPD in North Carolina.

METHODS

We determined the prevalence of self-reported COPD and characteristics of affected persons using data from the 2009 North Carolina Behavioral Risk Factor Surveillance System (BRFSS) survey. We also determined the number of persons with COPD in nursing homes and adult care or family care homes. We drew conclusions about the impact of COPD from data regarding mortality, hospitalizations, emergency department visits, prednisone use, and health impairment.

RESULTS

The age-adjusted prevalence of COPD among BRFSS survey respondents was 5.6%, and about 10,000 adults in nursing homes, adult care homes, or family care homes had COPD; thus we estimate that nearly 408,000 adults in North Carolina had COPD in 2009. Rates of self-reported COPD were highest among elderly individuals, smokers, individuals with less education, and those with lower incomes. Mental and physical impairment were significantly worse in those with COPD, two-thirds of whom reported that dyspnea affected their quality of life. Prednisone use was reported by 27.4% of persons with COPD, 11.4% of respondents with COPD had been hospitalized for this condition within the preceding year, and COPD admissions accounted for 1.44% of all hospital charges. Asthma, heart disease, stroke, and diabetes mellitus were significantly more common in persons with COPD. In terms of mortality, COPD was the fourth leading cause of death (n = 4,324); 77% of COPD deaths were among persons who had no education beyond high school, and 53% of those who died were women. COPD was reported in 17.1% of deaths from all causes, 21% of deaths from asthma, 10.1% of deaths from lung cancer, and 6.7% of deaths from heart disease.

LIMITATIONS

These data are based on population and health care database estimates and are approximations.

CONCLUSION

COPD has substantial effects on the health of North Carolinians.

Review of guidelines and the literature in the treatment of acute bronchospasm in chronic obstructive pulmonary disease

In 2002, an estimated 11.2 million adults in the United States had chronic obstructive pulmonary disease (COPD). Guidelines for the management of the disease have been published by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the American Thoracic Society-European Respiratory Society. Several other organizations are in the process of preparing guidelines for COPD, most based on the GOLD report. The most important pharmacologic intervention in COPD is treatment with bronchodilator drugs. This intervention applies not only to stable COPD, but also to exacerbations (flares) of the disease. Prevention strategies have been developed for acute exacerbations, and management strategies include using short-acting beta(2)-agonists, systemic corticosteroids, and antibiotics, in both at home and hospital settings.

An update on chronic obstructive pulmonary disease

OBJECTIVE

Provide an update on the diagnosis and management of chronic obstructive pulmonary disease (COPD) based on new international and national guidelines. COPD affects approximately 5% to 7% of adults in the United States, with a higher prevalence in elderly persons (10% in elderly males).

DATA SOURCE

A Medline search of relevant articles and the Global Initiative for Obstructive Lung Disease and the American Thoracic Society/European Respiratory Society COPD Guidelines.

STUDY SELECTION

Articles and current guidelines relevant to pharmacists working with COPD patients in extended-care facilities.

DATA SYNTHESIS

COPD is a chronically progressive disease that ultimately leads to major health impairment. New international and national guidelines recently have become available; these guidelines provide extensive insight into many aspects of the disease. Key interventions include early diagnosis, use of pulmonary-function testing, smoking cessation, supplemental oxygen, pulmonary rehabilitation, optimization of pharmacological therapies, and preventing--as well as minimizing--the impact of acute exacerbations of COPD. Optimizing the use of bronchodilators and, in selected patients, the use of corticosteroids are especially important pharmacological interventions in the management of COPD. Patients are started on short-acting bronchodilators; long-acting agents can be added and, in some patients, inhaled corticosteroids can be added as well. Other pharmacological interventions include smoking cessation therapies and the use of anti-infective and mucolytics/expectorants.

CONCLUSION

Pharmacists can assist in proper drug selection and administration in COPD patients in long-term care facilities. In addition, they can assist in preventing complications of drug therapy such as steroid-induced osteoporosis.

Outcomes associated with initiation of different controller therapies in a Medicaid asthmatic population: a retrospective data analysis

BACKGROUND

Outcomes in asthmatic patients may vary depending on the controller medication used. Observational studies of outcomes of asthma therapy are needed to understand the implications of choice of controller in different populations.

OBJECTIVES

To determine whether there are differences in health care use and costs of asthma treatment in asthma patients treated with montelukast compared with fluticasone proponiate 44 microg.

METHOD

Using data from the North Carolina Medicaid program, we compared continuously enrolled asthmatic patients starting either fluticasone propionate 44 microg (FP44), an inhaled corticosteroid (ICS) (n = 312), or montelukast 5 and 10 mg, an oral leukotriene modifier (LM) (n = 398) between the years 1998 and 1999. A secondary analysis compared continuously enrolled asthmatic patients already using ICS as controller therapy initiating either salmeterol (long-acting beta-agonist) (n = 97) or montelukast (n = 101) in the year 1998. Patients were followed for 1 year pre- and postcontroller or additional controller initiation for health care service use, medication refill patterns, and costs.

RESULTS

There were no significant differences in the adjusted asthma-related health care costs between the montelukast and FP44 groups. In both groups, physician visits were significantly higher in year 2 (p < 0.01) than in year 1. We found montelukast users to be more adherent with prescription refills (using measures of medication possession) even after allowing for a wider adherence range for FP (RR = 2.53; 95% CI = 1.50-4.26), although patients using montelukast were more likely than patients with fluticasone to switch controller pharmacotherapy (RR = 1.53; 95% CI = 1.12-2.09). Similarly, there were no differences in health care service use and costs between the montelukast and salmeterol groups, with the exception of a 33% reduction (p < 0.01) in number of inhaled corticosteroid refills in the second year in the salmeterol group.

CONCLUSION

There were no cost and major health care use differences between the two primary or secondary controller therapies in the postinitiation year. Although FP was associated with lower rate of controller switch, montelukast use was associated with significantly better treatment adherence in patients with treatment persistence in this population of Medicaid-enrolled asthmatic patients. The addition of salmeterol as additional controller was associated with a significant decrease in inhaled corticosteroid use, suggesting decreased adherence in patients on the two-drug regimen.

Pharmacokinetics of vancomycin in adult cystic fibrosis patients

Although the depositions of many antibiotics are altered in cystic fibrosis patients, that of vancomycin has not been studied. To assess vancomycin pharmacokinetics, 10 adult cystic fibrosis patients were given a parenteral dose of vancomycin (15 mg/kg) during the first 72 h of hospitalization for acute bronchopulmonary exacerbation. Blood samples were obtained at 0, 1, 1.25, 1.5, 2, 3, 4, 6, 8, 12, 15, and 24 h. The mean (standard deviation) weight, measured creatinine clearance, and Taussig clinical score were 51 (13) kg, 130 (39) ml/min/1.73 m2, and 64 (13), respectively. Multicompartmental pharmacokinetic parameters were best described by a two-compartment model. The mean (standard deviation) volume of distribution, total body clearance, and terminal elimination rate constant were 0.58 (0.15) liter/kg, 91 (19) ml/min/1.73 m2, and 0.123 (0.05) h-1, respectively. These values were consistent with vancomycin pharmacokinetic parameters obtained in previous studies of healthy adult volunteers. Vancomycin dosages predicted by using a two-compartment Bayesian model were approximately 15 mg/kg every 8 to 12 h. There were poor correlations between clinical score or creatinine clearance and any pharmacokinetic parameter (r values of < 0.32). The coefficient of correlation between urine flow rate and total body clearance was 0.7 (P < 0.05). Adult cystic fibrosis patients exhibit a disposition of vancomycin similar to that exhibited by healthy adults, and thus cystic fibrosis does not alter vancomycin pharmacokinetics.

Allergic reactions to parenteral beta-lactam antibiotics in patients with cystic fibrosis

Certain antibiotics, particularly piperacillin, have been reported to be associated with a high incidence of allergic reactions in patients with cystic fibrosis. We initiated a study to determine the relative frequency of allergic reactions, ie, drug-induced fever and rash, to parenteral beta-lactam antibiotics in adult patients with cystic fibrosis. Charts of 111 patients were reviewed for each hospitalization to assess allergic reactions. Of 90 evaluable patients, 26 patients developed one or more allergic reactions to beta-lactam antibiotics. The number of allergic reactions per number of patients receiving specific antibiotics were carbenicillin (4/56), mezlocillin (7/42), piperacillin (11/31), ticarcillin (1/20), cefazolin (0/24), ceftazidime (1/35), imipenem/cilastatin (4/16), and nafcillin (3/36). The mean time to onset of drug-induced fever or of rash was 9.1 days. As a group penicillins had a higher frequency of allergic reactions than cephalosporins. The frequency of reactions was greatest with acylaminopenicillins (mezlocillin and piperacillin) and imipenem/cilastatin. The results of this study indicate that in addition to piperacillin, mezlocillin and imipenem/cilastatin may be associated with a high incidence of allergic reactions in patients with CF.

Arthropathy secondary to ciprofloxacin in an adult cystic fibrosis patient

OBJECTIVE

To report a case of possible ciprofloxacin-induced arthropathy in an adult patient with cystic fibrosis (CF).

CASE SUMMARY

A 25-year-old man with CF received three separate courses of ciprofloxacin therapy at usual doses for acute pulmonary exacerbations of his disease. During the second and third courses, the patient experienced bilateral swelling of his knees between two to three weeks after initiation of each course. Both times symptoms markedly decreased after discontinuation of the drug. The patient had no prior history of arthropathy. Furthermore, during the last two acute exacerbations of his CF, he did not receive ciprofloxacin and did not experience any symptoms of arthropathy.

DISCUSSION

Prior cases of quinolone-induced arthropathy involving pediatric CF patients or adult patients without CF have been reported in the literature. We report the first case of such an arthropathy in an adult patient with CF. The findings are supported by a rechallenge with the drug.

CONCLUSIONS

It is likely that ciprofloxacin may produce arthropathy in adult as well as pediatric patients with CF. Quinolones should be considered as a possible cause of arthropathy in adult CF patients.

Compatibility of ceftazidime and aminophylline admixtures for different methods of intravenous infusion

OBJECTIVE

Aminophylline and ceftazidime are sometimes used concurrently in patients with respiratory disorders. Parenteral aminophylline usually is administered as a constant infusion, and ceftazidime is given intermittently or less commonly as a constant infusion. We evaluated the stability and compatibility of the two drugs when aminophylline is given as a constant intravenous infusion and ceftazidime is administered simultaneously either through a y-site (piggyback method) or as a continuous infusion (constant infusion method).

DESIGN

The chemical stability of intravenous aminophylline and ceftazidime in dextrose 5% and NaCl 0.9% for both methods was studied. Three different formulations of ceftazidime from the same manufacturer were studied (minibag using reconstituted ceftazidime, premixed minibag, and ceftazidime arginine). For the piggyback and constant infusion methods, samples were collected at 0, 1, and 2 hours; and 0, 6, and 24 hours, respectively. All experiments were conducted in triplicate. Samples were analyzed in duplicate by a stability-indicating HPLC assay method.

OUTCOME MEASURE

Ceftazidime and aminophylline were considered stable if concentrations remained above 90 percent of the original concentrations over the time periods studied.

RESULTS

Ceftazidime was determined to be compatible with aminophylline in the piggyback method. In contrast, when aminophylline and ceftazidime were admixed in the same intravenous container (constant infusion method), the two drugs were not stable.

CONCLUSIONS

These data indicate that aminophylline and ceftazidime admixtures are incompatible when prepared in the same intravenous container, which may occur if both are given as a constant infusion. The two drugs are compatible when the ceftazidime is piggybacked into a primary intravenous set in which aminophylline is administered as a constant infusion.

Use of antimicrobial drugs in adults before and after removal of a restriction policy

The effects on the quantity and quality of antimicrobial drug use of removing an antimicrobial restriction policy are reported. Monthly totals for the number of courses of antimicrobial therapy and expenditures based on grams used were obtained from pharmacy records on adult inpatients for a portion (July-December 1987) of the restriction policy term and for the six months (July-December 1988) immediately after the policy ended. Data were obtained for nine restricted drugs and for three that were never restricted. Retrospective drug-use reviews were conducted for ceftazidime and imipenem-cilastatin. For the restricted agents, the total number of courses of therapy increased by 158% after the restriction policy was removed, and total expenditures increased by 103%. There were no significant changes in the number of courses of therapy or cost for the unrestricted antimicrobials. In the postrestriction period, ceftazidime and imipenem-cilastatin were used more often in patients who were less critically ill. Inappropriate use of imipenem-cilastatin occurred significantly more often after the restrictions were removed. Other factors potentially affecting the use of antimicrobials, such as patient age and the incidence of nosocomial infections, did not differ substantially between the two periods. The removal of an antimicrobial restriction policy resulted in increased use of and higher expenditures for previously restricted agents, as well as an increase in the inappropriate use of at least one agent.

Tobramycin administration and blood sampling through a dual-lumen peripheral intravenous catheter

The objective of this study was to determine if a peripheral dual-lumen catheter could be used for accurate tobramycin blood concentration measurement when drug administration and blood sampling were undertaken through separate lumens of the catheter. Eleven adult volunteers received tobramycin 1.5 mg/kg iv infused over 30 minutes through the distal lumen of the dual-lumen catheter every eight hours for two doses. Multiple blood samples were obtained concurrently from the proximal lumen of the catheter and a single-lumen catheter in the contralateral arm after each dose. Blood samples were also obtained through the distal lumen before and 30 minutes after the end of the infusion. Accurate blood samples were obtainable through the dual-lumen catheter in only 5 of 11 subjects due to either infiltration or difficulties in catheter placement. In the subjects from whom accurate blood samples were obtained, approximately 20 minutes postinfusion was the amount of time required before measured tobramycin serum concentrations were similar between the arm in which the drug was infused (site of the dual-lumen catheter) and the contralateral arm. At standard times for obtainment of trough (just prior to the infusion) and peak (30 minutes after the end of a 30-minute infusion) tobramycin serum concentrations from the proximal lumen of the dual-lumen catheter were numerically similar to those obtained from the contralateral arm. This preliminary study indicates that the dual-lumen catheter provides accurate aminoglycoside concentrations when patent relative to blood withdrawal and if peak blood samples are obtained at least 30 minutes postinfusion through the recommended lumen. However, further study in a larger number of subjects is required before routine use of this device can be recommended.

Reassessment of cross-reactivity of spironolactone metabolites with four digoxin immunoassays

Spironolactone and one of its metabolites, canrenone, cross-react with some digoxin immunoassays to result in erroneous serum digoxin concentrations. Recently, additional compounds, 7-alpha-thiomethylspirolactone (7-a-TMS) and 6-beta-hydroxy-7-alpha-thiomethylspirolactone (6-B-OH-7-a-TMS), have been reported to be quantitatively important metabolites of spironolactone. This study was initiated to evaluate the cross-reactivity of these metabolites, canrenone, and spironolactone with four different digoxin immunoassays. Blank serum was spiked with each compound to yield concentrations reported to occur in vivo. Samples were analyzed in duplicate by each of the following immunoassays: fluorescence polarization immunoassay (FPIA); affinity-column-mediated immunoassay (ACMIA); radioimmunoassay (RIA); and enzyme immunoassay (EIA). The 7-a-TMS metabolite cross-reacted with both the RIA and ACMIA methods. Apparent digoxin concentrations were as great as 0.39 ng/ml for this metabolite at the highest concentration evaluated, 600 ng/ml. At the lowest concentrations evaluated with the 7-a-TMS metabolite, 50 ng/ml, apparent digoxin concentrations as high as 0.28 ng/ml were reported. The 6-B-OH-7-a-TMS metabolite did not cross-react to a significant extent with any of immunoassays studied. Canrenone cross-reacted with the ACMIA method at a concentration of 100 ng/ml. The EIA method exhibited no apparent cross-reactivity with any of the compounds, whereas the FPIA method exhibited minimal cross-reactivity. The results of this study indicate that the 7-a-TMS metabolite cross-reacts to a significant extent with some immunoassays; however, this is not true for the 6-B-OH-7-a-TMS metabolite.

Accuracy of tobramycin delivery by four i.v. infusion methods

The accuracy of tobramycin delivery by four methods of intermittent intravenous infusion was studied in 11 healthy male volunteers. Subjects received intravenous tobramycin (as the sulfate salt) 1.5 mg/kg by each of four infusion methods in a nonblinded, randomized, four-way crossover design. The methods used for intravenous infusion were (1) minibag via gravity flow (MG), (2) minibag with the secondary infusion tubing inserted below a volumetric infusion pump (MP), (3) metered chamber via volumetric infusion pump (MC), and (4) syringe pump (SP). Doses were diluted to a volume of 50 mL, except for the two minibag methods, for which the dilution was necessarily greater because of manufacturer overfill. Intravenous flow rates for both primary fluid and drug administration were set at 100 mL/hr, and the duration of drug infusion was documented by observation for each administered dose. The fluid volume of 12 minibags was measured to assess manufacturer overfill. Fluid remaining in the secondary i.v. tubing for the minibag methods was collected after the infusion. Seventeen blood samples were obtained before and at various time intervals after each dose and analyzed in duplicate for tobramycin content by fluorescence polarization immunoassay. A mean of 10% of each dose remained in the secondary i.v. tubing at the completion of the infusion for the minibag methods, whereas less than 1% of each dose remained in the secondary tubing for the SP method.(ABSTRACT TRUNCATED AT 250 WORDS)