Comparison of linezolid with oxacillin or vancomycin in the empiric treatment of cellulitis in US hospitals

In this decision-model analysis, the authors compared overall clinical efficacy and total cost of empiric treatment of hospitalized cellulitis patients prescribed linezolid and oxacillin or vancomycin. The authors hypothesized that, when used appropriately, empiric linezolid treatment is an effective, potentially cost-saving antibiotic compared with treatment initiated with oxacillin or vancomycin. Data on efficacy, duration of antibiotic treatment, and hospital stay for first-line treatment success were obtained from two clinical trials. Other medical resource use data were obtained from an expert panel of clinicians. US hospital direct medical costs were determined using standard costing techniques. Overall efficacy and total cost of treatment were estimated for combinations of the risk of being infected with methicillin-resistant pathogens. Sensitivity analyses were performed to test the impact of changes in major assumptions. Overall first-line efficacy is better for empiric treatment initiated with linezolid than with oxacillin or vancomycin across the spectrum of the risk of being infected with methicillin-resistant bacteria. The average total cost of treatment is lower for treatment initiated with linezolid than with vancomycin across the spectrum, or than with oxacillin when the risk of being infected with methicillin-resistant pathogens is 18.7 % or higher. Linezolid appears to be at least as effective as vancomycin or oxacillin for empiric treatment of hospitalized cellulitis patients. Linezolid is likely to be less costly compared with vancomycin at all resistance rates and with oxacillin when the risk of infection with methicillin-resistant pathogens is greater than 18.7 %, a resistance rate commonly seen in US hospitals.

Early switch and early discharge opportunities in intravenous vancomycin treatment of suspected methicillin-resistant staphylococcal species infections

BACKGROUND

Patients with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase negative staphylococci (MR-CoNS) infections are usually treated with intravenous (IV) vancomycin and remain hospitalized for the duration of IV therapy. Oral linezolid has excellent bioavailability and activity against MRSA and MR-CoNS and offers the potential for outpatient treatment of MRSA and MR-CoNS infections.

OBJECTIVE

To determine the potential for early switch (ES) from IV vancomycin to oral linezolid and subsequent early discharge (ED) in hospitalized, adult patients treated for an MRSA or MR-CoNS infection.

METHODS

We conducted a retrospective cohort study at the Veterans Administration Greater Los Angeles Healthcare System from January 1 through December 31, 2000. Potential reductions in vancomycin use, hospital length of stay (LOS), and economic savings were determined.

RESULTS

A total of 103 of 177 (58%) treatment courses for MRSA or MR-CoNS infections were potentially eligible for ES, with annual and mean decreases in vancomycin use of 535 defined daily doses and 5.2 days per event. Of the ES cohort, 55 of 103 (53%) courses were potentially eligible for ED, with an annual and mean reduction in LOS of 181 days and 3.3 days per event. The total potential savings was $220,181, at an average of $3,478 per event.

CONCLUSION

Early switch to oral linezolid for treatment of MRSA or MR-CoNS infections could reduce vancomycin use, hospital length of stay, and economic costs.

Mississippi mud no more: cost-effectiveness of pharmacokinetic dosage adjustment of vancomycin to prevent nephrotoxicity

OBJECTIVE

To determine the cost-effectiveness of pharmacokinetic dosage adjustment of vancomycin to prevent nephrotoxicity. An analysis was performed for subpopulations of patients receiving nephrotoxic agents (aminoglycosides, amphotericin, and acyclovir), those in the intensive care unit, and those on the oncology service.

METHODS

Decision analysis was used to model the cost-effectiveness of pharmacokinetic dosage adjustment of vancomycin. The reference case was determined, in part, by a retrospective review of 200 patients randomly selected from our clinical pharmacology consultation service. Patients were aged 18 years or older and had received intravenous vancomycin for at least 48 hours, with at least two--one peak and one trough--vancomycin serum concentrations obtained during therapy. Results of published clinical trials were used to determine the probability of vancomycin-induced nephrotoxicity.

RESULTS

The mean cost of treating nephrotoxicity was 11,233 dollars at our institution. The mean cost for all patients was 25,166 dollars (sensitivity analysis 15,000-27,500 dollars)/nephrotoxic episode prevented. The subgroup analysis revealed a cost of 8,363 dollars (sensitivity analysis 4,368-10,500 dollars)/nephrotoxic episode prevented in intensive care patients, 5,000 dollars (sensitivity analysis 1,687-13,250 dollars ) in oncology patients, and a dominant strategy showing a cost savings of 5,564 dollars (sensitivity analysis 2,724-12,428 dollars) in those receiving concomitant nephrotoxins.

CONCLUSION

Although pharmacokinetic monitoring and dosage adjustment are effective methods for reducing the toxicity of many drugs, controversy exists regarding the necessity of such monitoring with vancomycin. Evaluation by decision analysis over a range of assumptions, varying probabilities, and costs reveals that pharmacokinetic monitoring and vancomycin dosage adjustment to prevent nephrotoxicity are not cost-effective for all patients. However, such dosage adjustment demonstrates cost-effectiveness for patients receiving concomitant nephrotoxins, intensive care patients, and probably oncology patients.

Cost effect of managing methicillin-resistant Staphylococcus aureus in a long-term care facility

OBJECTIVES

The purpose of this study was to measure the total consumption of resources involved in the care of a long-term care facility (LTCF) resident infected with methicillin-resistant Staphylococcus aureus (MRSA).

DESIGN

A retrospective cohort study.

SETTING

A 375-bed LTCF that provides two levels of care.

PARTICIPANTS

Ninety LTCF residents infected with Staphylococcus aureus (mean age +/- standard deviation for methicillin-sensitive Staphylococcus aureus (MSSA) patients = 85 +/- 8.8, for MRSA patients = 82 +/- 9.5, P =.127; 49 MSSA and 41 MRSA patients). Inclusion criteria consisted of identification of a positive S. aureus culture in addition to symptoms/signs consistent with infection. Patients colonized with S. aureus were excluded.

MEASUREMENTS

A standardized data collection tool was used to conduct chart and database review throughout the defined infection period. The type of information collected included demographic, infection characterization, antibiotic regimen, resource assessment, and cost data. The cost data were further categorized into total pharmaceutical, infection management, physician care, nursing care, and total infection cost.

RESULTS

One hundred eleven cases were identified, with 90 cases eligible for evaluation. No difference in population demographics was noted between groups. A significantly higher number of patients in the MRSA group had an indwelling device (P <.001), pressure ulcer(s) (P =.028), or diabetes mellitus (P =.007). There was a significantly higher number of patients with congestive heart failure in the MSSA group (P =.047), but no difference existed in the primary infection site (P =.297) or the incidence of patients with more than two comorbidities (P =.509). The infection characterization variables included were also similar between groups. The most prevalent infection site was the urinary tract (48%) followed by skin/skin structure (38%). Because the majority of patients (82%) developed infection at least 30 days after their LTCF admission, the infections may be considered to have been largely LTCF acquired. The median infection management cost of an MRSA infection was six times greater than that of a MSSA infection (P <.001), whereas the median associated nursing care cost was two times greater (P =.001). The median overall infection cost associated with MRSA was 1.95 times greater than that of MSSA (median (range): MSSA 1,332 US dollars (268-7,265 US dollars) vs MRSA 2,607 US dollars (849-8,895 US dollars), P <.001). Nursing care cost constituted the major portion of the overall infection cost in both groups (MSSA 51%, MRSA 48%). Evaluation of antimicrobial management revealed that infected residents were treated with a wide array of combination therapies (65% of patients received combination therapy).

CONCLUSIONS

The management of a resident infected with MRSA was much more costly to the LTCF than that of an MSSA-infected patient. The general care of the patient and not the specific antibiotic regimen influenced the large difference in cost between groups. The approach to the antibiotic management of these patients was variable. A more streamlined approach to infection management that facilitates a faster cure rate may dramatically lower resource consumption and improve patient outcomes.

Comparison of vancomycin versus cefazolin as initial therapy for peritonitis in peritoneal dialysis patients

The incidence of peritonitis ranges from 1 episode every 24 patient treatment months to 1 episode every 60 patient treatment months [Keane WF, et al. ISPD Guidelines/Recommendations. Adult peritoneal dialysis-related peritonitis treatment recommendations: 2000 update. Perit Dial Int 2000; 20:396-411.]. Gram-positive organisms account for over 80% of continuous ambulatory peritoneal dialysis (PD)-associated peritonitis. Recent fear of vancomycin-resistant enterococci (VRE) has prompted suggestions of limiting vancomycin use. Fifty-one episodes of peritonitis in 30 patients studied over 2 years were evaluated. Cloudiness of the PD fluid and/or abdominal pain were considered suggestive of peritonitis and were confirmed by cell count and culture. Baseline cell count, Gram stain, and cultures were obtained, with periodic follow-up. Patients were randomized to receive either vancomycin 1 g/L intraperitoneally (IP) as loading dose, repeated on day 5 or day 8, depending on residual renal function, for 2 weeks, or cefazolin 1 g in the first PD bag and continued with 125 mg/L every exchange for 2 or 3 weeks, depending on culture results. All patients also received gentamicin 40 mg IP every day until the culture results were available. A similar randomized trial comparing vancomycin and cefazolin in the past used a lower concentration of cefazolin 50 mg/L [Flanigan MJ, Lim VS. Initial treatment of dialysis associated peritonitis: a controlled trial of vancomycin versus cefazolin. Perit Dial /nt 1991; 11:31-7.]. Peritoneal dialysate fluid cultures revealed 31(60.7%) gram-positive organisms, 7(13.7%) gram-negative organisms, and 2 (3.9%) cultured yeast; 11 (21.5%) cultures yielded no growth. The incidence of peritonitis at our center was 1 episode every 42 patient treatment months. No case of VRE was noted. There was no statistical difference in clinical response or relapse rate for the two protocols. It was the authors' and nurses' observation that patient compliance and satisfaction was better with vancomycin, and the cost per treatment was 23% less than cefazolin. Based on these data we believe vancomycin should still be considered for first-line treatment of PD-associated peritonitis.

Use of insurance claims data to assess outpatient antimicrobial therapy for gram-positive infections

With the increasing frequency of antibiotic-resistant gram-positive infections in the United States, many patients are being treated outside the hospital setting. The majority of studies on the cost of outpatient antimicrobial therapy involve retrospective medical record review or prospective data collection. These methods tend to be expensive and time consuming, and often fail to produce a sufficiently large sample size. Analysis of insurance claims data offers a convenient approach for studying the costs associated with outpatient therapy for gram-positive infections. To demonstrate this approach, a study of the cost of intravenous vancomycin home care therapy was conducted using claims data from a large insurance company.

Cost perspectives for outpatient intravenous antimicrobial therapy

Intravenous antimicrobial therapy often continues after a patient is discharged from the hospital or it begins in the outpatient setting. Reimbursement for this therapy varies by payer. The United States Outpatient Parenteral Antibiotic Therapy (OPAT) Outcomes Registry is a valuable resource for quantifying cost by payer, as well as for describing practice patterns and adverse events related to intravenous antimicrobial therapy. To describe the reimbursement structure and cost of intravenous vancomycin home care therapy for four different types of payers, a survey of home infusion companies was done. Also surveyed were infusion programs participating in the OPAT Outcomes Registry, representing four different types of payers, to determine the cost of outpatient intravenous therapy. A retrospective cohort study of these infusion programs was conducted to describe practice patterns and to identify adverse events that resulted from intravenous vancomycin. We found that the cost of outpatient therapy was substantial, although nonuniform, across payer types. Alternative outpatient therapies associated with lower risks for adverse events and lower costs should be considered.

Economic evaluation of linezolid, flucloxacillin and vancomycin in the empirical treatment of cellulitis in UK hospitals: a decision analytical model

Standard antibiotic treatment of infections has become more difficult and costly due to treatment failure associated with the rise in bacterial resistance. New antibiotics that can overcome such resistant pathogens have the potential for great clinical and economic impact. Linezolid is a new antibiotic that is effective in the treatment of both antibiotic-susceptible and antibiotic-resistant Gram-positive bacterial infections, including those resistant to other available antibiotics. This breadth of activity is unique in existing antibiotics for Gram-positive bacteria and serves as the rationale for exploring the hypothesis that linezolid is an appropriate choice when considering empirical treatment of cellulitis in complicated or compromised patients in the nosocomial setting. A decision-modelling approach was used to compare the predicted first-line treatment efficacy and direct medical costs of linezolid with standard treatment of cellulitis among hospitalized patients. For the purposes of this analysis, standard care is defined along two main pathways: (1) initiating care with intravenous (iv) flucloxacillin, switching to vancomycin if the pathogen is found to be resistant to flucloxacillin, or maintaining flucloxacillin if the pathogen is found susceptible, or when culture and sensitivity analysis is inconclusive; or (2) initiating care with vancomycin, switching to iv flucloxacillin if the pathogen is found susceptible to flucloxacillin, maintaining vancomycin if the infection is found resistant, or when culture and sensitivity are inconclusive. For those patients taking iv flucloxacillin, a switch to oral flucloxacillin was allowed when clinically appropriate. We hypothesized that the cost of care of initiating treatment with linezolid would be less than that for both vancomycin and flucloxacillin in resistance risk ranges typically encountered in UK hospitals. In addition, while the registration trials showed equivalence of linezolid with the comparators in known or suspected methicillin-resistant Staphylococcus aureus (MRSA) and in known or suspected methicillin-susceptible Staphylococcus aureus (MSSA) (vancomycin and oxacillin) respectively, we hypothesized that first-line success rates would be higher in empiric treatment with linezolid. Efficacy data were obtained from recent clinical trials with linezolid and standard treatment, and medical resource utilization was obtained from an expert panel of clinicians who were questioned regarding resistant and susceptible infections separately. UK hospital direct medical costs of treatment were determined using standard costing techniques. Base case analyses assumed a residual 80% unknown pathogen rate after culture and susceptibility based on a physician survey and supported in the literature. The analysis in this model predicts that initiating empirical treatment of cellulitis with linezolid will (1) result in higher overall success rates than flucloxacillin for first-line treatment, regardless of resistance risk and (2) be less costly than initiating treatment with flucloxacillin when the likelihood of a patient being infected by a resistant pathogen is greater than 24.1%. Furthermore, initiating treatment with linezolid is predicted to result in higher overall success rates and be less costly than vancomycin across the entire spectrum of the patients' risk of being infected by a resistant pathogen.

[The comparative costs of vancomycin treatment versus teicoplanin in osteoarticular infection caused by methicillin-resistant staphylococci]

This clinical and economical study compared two glycopeptides regimen i.e., vancomycin and teicoplanin in the treatment of osteoarticular infection involving methicillin-resistant staphylococcus. After randomization, 15 patients (group 1) received vancomycin (23 F per gram) in continuous infusion through a central venous catheter and 15 others (group 2) intramuscular teicoplanin (311-357 F a 400 mg vial). The clinical study focused on treatment tolerance in an in-patient setting as well as in a non in-patient one. The cost analysis focused on total expenses including those of antibiotics, those of medical devices for antibiotic administration and those of the complications caused by the antibiotics use. Total expenses per patient averaged 8744 F with vancomycin and 8555 F with teicoplanin (NS). The apparent money saving by using a cheap antibiotic (i.e. vancomycin) was illusionary as one took in account the expenses for medical devices e.g., central venous catheters required to administer vancomycin and the complications due to the use of these devices.

Continuous versus intermittent infusion of vancomycin in severe Staphylococcal infections: prospective multicenter randomized study

A continuous infusion of vancomycin (CIV) may provide an alternative mode of infusion in severe hospital-acquired methicillin-resistant staphylococcal (MRS) infections. A multicenter, prospective, randomized study was designed to compare CIV (targeted plateau drug serum concentrations of 20 to 25 mg/liter) and intermittent infusions of vancomycin (IIV; targeted trough drug serum concentrations of 10 to 15 mg/liter) in 119 critically ill patients with MRS infections (bacteremic infections, 35%; pneumonia, 45%). Microbiological and clinical outcomes, safety, pharmacokinetics, ease of treatment adjustment, and cost were compared. Microbiological and clinical outcomes and safety were similar. CIV patients reached the targeted concentrations faster (36 +/- 31 versus 51 +/- 39 h, P = 0.029) and fewer samples were required for treatment monitoring than with IIV patients (7.7 +/- 2.2 versus 11.8 +/- 3.9 per treatment, P < 0.0001). The variability between patients in both the area under the serum concentration-time curve (AUC(24h)) and the daily dose given over 10 days of treatment was lower with CIV than with IIV (variances, 14,621 versus 53,975 mg(2)/liter(2)/h(2) [P = 0.026] and 414 versus 818 g(2) [P = 0.057], respectively). The 10-day treatment cost per patient was $454 +/- 137 in the IIV group and was 23% lower in the CIV group ($321 +/- 81: P < 0.0001). In summary, for comparable efficacy and tolerance, CIV may be a cost-effective alternative to IIV.

Clinical consequences and cost of limiting use of vancomycin for perioperative prophylaxis: example of coronary artery bypass surgery

Routine us of vancomycin for perioperative prophylaxis is discouraged, principally to minimize microbial resistance to it. However, outcomes and costs of this recommendation have not been assessed. We used decision-analytic models to compare clinical results and cost-effectiveness of no prophylaxis, cefazolin, and vancomycin, in coronary artery bypass graft surgery. In the base case, vancomycin resulted in 7% fewer surgical site infections and 1% lower all-cause mortality and saved $117 per procedure, compared with cefazolin. Cefazolin, in turn, resulted in substantially fewer infections and deaths and lower costs than no prophylaxis. We conclude that perioperative antibiotic prophylaxis with vancomycin is usually more effective and less expensive than cefazolin. Data on vancomycin's impact on resistance are needed to quantify the trade-off between individual patients' improved clinical outcomes and lower costs and the future long-term consequences to society.

Growing problem of methicillin resistant staphylococci--Indian scenario

In the present study MRSA prevalence increased from 12% in 1992 to 80.83% in 1999. Indian literature shows that MRSA incidence was as low as 6.9% in 1988 and reached to 24% and 32.6% in Vellore and Lucknow in 1994 and was of the same order in Mumbai, Delhi and Bangalore in 1996 and in Rohtak and Mangalore in 1999. However, in some of the centres it was as high as 87%. All the MRSA isolates in India including in the present study were sensitive to vancomycin and resistance to netilmycin appears to be low among MRSA isolates in India. All the MRSA isolates were also found to be sensitive to teicoplanin in the present study. Like in other Indian studies, resistance to cotrimoxazole, erythromycin, gentamicin, other penicillins and cephalosporins appeared to be a common feature for MRSA isolates in the present study.

[Vancomycin and teicoplanin use as antibiotic prophylaxis in cardiac surgery: pharmacoeconomic study]

BACKGROUND

To assess the economical impact of vancomycin use versus teicoplanin use as antibiotic prophylaxis for patients undergoing cardiac surgery for valve replacement (VR) and coronary artery by-pass (CABS) procedures.

PATIENTS AND METHODS

This is an ancillary cost minimization analysis of a double blinded, parallel groups, randomised clinical trial (RCT), with the main objective of comparing the safety and efficacy of these antibiotics. 500 patients were included in the study; 267 in the CABS group and 233 in the VR group. The CABS patients received 1 g vancomicin or 400 mg teicoplanin, plus 150 mg netilmicin. The VR group received a second dose of each drug after extracorporeal circulation. In order to calculate the costs we considered the direct cost of the drug, the i.v. mix and the administration costs, together with personnel and structure costs. We considered two different situations: the administration of drugs within the surgical room theatre and in the medical ward.

RESULTS

The demographic data of both groups were comparable. The frequency of severe adverse drug reactions (ADR) were similar (0.4%) in both groups, as well as the post-operative infection rates (8.6%). Differences were seen in the frequencies of low severity ADRs: 20.4% in the vancomycin group and 1.6% in the teicoplanin group. When the antibiotics were administered in the surgical room, among CABS patients the costs were 8,265 pts. for the teicoplanin group and 12,005 pts. for the vancomycin group; while among VR patients, costs were respectively 11,661 pts. and 14,528 pts. Administration costs of teicoplanin and vancomycin within a medical ward setting, however, the costs were 6,740 pts. and 2,809 pts. for CABS patients, and 5,308 pts. and 10,140 pts. for VR patients, respectively.

CONCLUSIONS

The costs of antibiotic prophylaxis among cardiac surgery patients heavily depends on the setting and circumstances of drug administration. The minimization cost analysis indicates that teicoplanin is the most cost-effective option if the drug is administered within the surgical area, while vancomycin is the less costly option when administered within the medical ward. However, if the second option is to be chosen, it is necessary to assure the right plasmatic drug levels of the antibiotic at the beginning of the surgical procedure.

[Cost of antibiotic therapy in neutropenic patients undergoing peripheral blood stem cell transplantation for breast cancer]

The increase in pharmaceutical costs, especially for expensive procedures such as bone marrow transplants, has led to the study of the economic impact of febrile neutropenia in peripheral blood stem cell transplantation (PBSCT). We analyzed 89 consecutive patients with breast cancer who underwent PBSCT. All patients developed febrile neutropenia and were administered an empirical intravenous regimen based on the combination of piperacillin-tazobactam and amikacin. We analyzed the direct costs of this treatment and grouped them into drug acquisition cost, administration costs (cost of the additional material), and preparation costs (time employed for the preparation and administration of the drug). We found that the overall cost was $1,110, 65% of which corresponded to the initial therapy and the rest (35%) to the use of additional antibiotics. This higher cost was especially related to the use of vancomycin or teicoplanin (50%). The acquisition costs accounted for 90% of the overall treatment costs. Thirty-six patients (40%) did not need additional antibiotics and the cost in this group was less ($663). We concluded that knowledge of the costs of pharmacological therapy for infection in PBSCT is indispensable for the appropriate development of treatment units, especially in terms of optimizing resources and comparing different therapeutic or prophylactic approaches.

Comparative pharmacoeconomic study of vancomycin and teicoplanin in intensive care patients

Randomized clinical trials and meta-analyses have not demonstrated any statistically significant differences between teicoplanin and vancomycin with regard to efficacy. A cost-minimization analysis was conducted to compare the economical impact of the treatment with vancomycin and teicoplanin in intensive care patients. Information on resource utilization was retrospectively collected from 100 consecutive clinical histories of patients hospitalized in a Spanish Intensive Care Unit, who had been given a glycopeptide antibiotic (50 teicoplanin and 50 vancomycin) for the treatment of a suspected or proven infection. Although personnel, material, and monitoring costs were higher in the vancomycin group, the acquisition costs and the total costs were much lower in this group, so the resulting total costs per day were 5508 ptas (33 euros) for vancomycin-treated patients and 9893 ptas (59.5 euros) for teicoplanin-treated patients. The savings with vancomycin for a 10-day course of treatment would be approximately 40697 ptas (244.5 euros) per patient. Results were consistent for a variety of conditions that were included in the sensitivity analysis.

Cost-effectiveness analysis of six strategies for cardiovascular surgery prophylaxis in patients labeled penicillin allergic

The cost-effectiveness of different approaches to antimicrobial prophylaxis for cardiovascular surgery patients labeled penicillin allergic was studied. A decision-analytic model was used to examine the cost-effectiveness of six strategies for antimicrobial prophylaxis in cardiovascular surgery patients at a tertiary care hospital. The strategies consisted of (1) giving vancomycin to all patients labeled penicillin allergic, (2) giving cefazolin to all patients labeled penicillin allergic, (3) giving vancomycin to all patients with a history suggesting an immunoglobulin E (IgE)-mediated reaction to penicillin and cefazolin to patients without such a history, (4) administering a penicillin skin test to patients with a history suggesting an IgE-mediated reaction to penicillin and giving vancomycin to patients with positive results and cefazolin to all others, (5) skin testing all patients labeled penicillin allergic and giving vancomycin to those with positive results and cefazolin to those with negative results, regardless of history, and (6) skin testing all patients and giving vancomycin to those with positive results or a history suggesting an IgE-mediated reaction to penicillin and cefazolin to all others. Giving cefazolin to all patients labeled penicillin allergic was the least expensive strategy but was associated with the highest rate of both anaphylactic and non-life-threatening serious reactions. Selective use of vancomycin in patients with a history suggesting an IgE-mediated reaction to penicillin was associated with an added cost and a slightly lower rate of anaphylaxis. Although skin-testing strategies may decrease both non-life-threatening and anaphylactic reactions, the incremental cost was high. When vancomycin was given to all patients labeled penicillin allergic, the incremental cost was very high. A decision-analytic model indicated that selective use of vancomycin is more cost-effective than indiscriminate use of vancomycin for surgical prophylaxis in cardiovascular surgery patients labeled penicillin allergic.

Vancomycin use in a university medical center: effect of a vancomycin continuation form

OBJECTIVE

To examine the impact of a new policy to ensure appropriate use of vancomycin in a 461-bed tertiary-care hospital.

DESIGN

We instituted a policy that allowed physicians to prescribe vancomycin but that required them to complete a vancomycin continuation form and document that use conformed to Hospital Infection Control Practices Advisory Committee (HICPAC) guidelines if they wished to continue the drug beyond 72 hours. Vancomycin was stopped automatically at 72 hours if use was not consistent with guidelines, if an infectious diseases consultant did not approve the drug, or if the form was not completed. A pharmacist and infectious diseases specialist monitored use of vancomycin prospectively and interacted with prescribers when indicated. Educational efforts were limited to printing the HICPAC guidelines on the form and providing information about the policy in a newsletter. Patterns of prescribing and the economic impact of the form were evaluated over a 6-month period.

RESULTS

Only 29% to 48% of vancomycin orders initially met HICPAC guidelines, but 77% to 96% of use was appropriate after 72 hours when the form was used. Inappropriate surgical prophylaxis, empirical therapy of intensive-care unit and transplant patients, and therapy for inadequately documented coagulase-negative staphylococcal infections remained problems. Vancomycin use fell from a mean of 136 (+/-52) g/1,000 patient days in the 12 months before the form to 78 (+/-22) g/1,000 patient days in the 9 months after institution of the form (P<.05). Net vancomycin acquisition costs and costs of ordering vancomycin serum levels fell by $357 and $19 per 1,000 patient days, respectively (P<.05). This represented annualized saving of approximately $47,000 in drug and monitoring costs. No adverse patient outcomes were seen as a result of the program.

CONCLUSIONS

A vancomycin continuation form can decrease inappropriate vancomycin use and may save money. Additional educational efforts may be required to increase compliance with HICPAC guidelines during initial prescribing.

Randomized prospective study comparing cost-effectiveness of teicoplanin and vancomycin as second-line empiric therapy for infection in neutropenic patients

BACKGROUND AND OBJECTIVE

The current health-care philosophy dictates that new therapies should always be evaluated for their economic impact. Along with acquisition cost, the cost of delivery, monitoring, adverse effects and treatment failure must also be considered when determining the total cost of therapy. These auxiliary costs can be significant and greatly alter the overall cost of a drug treatment. We conducted a prospective randomized study to evaluate the efficacy, safety and cost of vancomycin and teicoplanin therapy in patients with neutropenia, after the failure of empirical treatment with a combination of piperacillin/tazobactam and amikacin.

DESIGN AND METHODS

Seventy-six febrile episodes from 66 patients with hematologic malignancies under treatment, neutropenia (neutrophils <500/mm3) and fever (38 degrees C twice or 38.5 degrees C once) resistant to the combination piperacillin/tazobactam and amikacin were included in the study.

RESULTS

Primary success of second-line therapy was obtained in 35 cases (46%) with no significant difference between vancomycin (17/38) and teicoplanin arms (18/38). No difference in renal or hepatic toxicity related to the antibiotic therapy was observed. The average cost per patient according to glycopeptide used was $450+/-180 for the teicoplanin group and $473+/-347 for the vancomycin group. Interestingly, in the teicoplanin arm, drug acquisition accounted for 97% of the total cost, while in the vancomycin arm administration and monitoring play an important role in overall costs.

INTERPRETATION AND CONCLUSIONS

In conclusion, our pharmacoeconomic analysis demonstrates that teicoplanin and vancomycin can be administered in neutropenic hematologic patients with similar efficacy and direct costs.

Outcome assessment of minimizing vancomycin monitoring and dosing adjustments

An approach to minimize monitoring of vancomycin therapy was evaluated in 120 patients, and results were compared with data from 120 patients in whom vancomycin therapy was monitored and adjusted based on serum peak and trough concentrations and traditional pharmacokinetic methods. Patients dosed by the nomogram (NM) had regimens adjusted based on actual body weight, estimated creatinine clearance, and a targeted trough concentration of 5-20 microg/ml. A single trough serum concentration was drawn only after 5 or more days of therapy. Overall, the average length of therapy was similar between groups (9.9 +/- 9.4 days NM and 8.6 +/- 7.2 days pharmacokinetic). The most common regimen for both groups was 1 g every 12 hours, although NM patients received significantly fewer grams/day (1.9 +/- 0.7 g/day) than the pharmacokinetic group (2.2 +/- 1.0 g/day, p<0.04). Patients dosed by NM also had significantly fewer regimen changes (0.63 +/- 0.96 vs pharmacokinetic 0.92 +/- 0.97, p=0.02) as well as significantly fewer serum concentrations measured/patient (1.08 +/- 1.9 vs 1.96 +/- 2.0, p=0.001). In addition, serum concentrations for NM patients were drawn later in therapy (5.4 +/- 2.5 vs 3.8 +/- 3.4 days, p=0.004). Of patients dosed by NM guidelines, 77 had trough concentrations drawn; these data were used to validate the nomogram. Seventy-two patients (94%) had trough concentrations in the target range of 5-20 microg/ml. No differences were found between groups with respect to cure, improvement, failure, or days to eradication, or with respect to nephrotoxicity. Finally, total drug cost/patient was not different between groups. A considerable cost savings to our institution was noted for patients dosed by NM compared with pharmacokinetics ($232.5 +/- 50.74 vs $403.75 +/- 70.97/mo, p=0.009) based on levels saved. Caution should be applied when generalizing our results to other patient populations.

Analysis of the value of empiric vancomycin administration in febrile neutropenia occurring after autologous peripheral blood stem cell transplants

We conducted a retrospective review of 125 patients undergoing high-dose therapy and stem cell rescue in order to evaluate the incidence of documented infection and the utility of the administration of vancomycin empirically. All patients received prophylactic oral quinolone therapy. Because neutropenia in this setting is relatively brief, 21 patients never manifested fever, and no patient died of infection. Of the remaining 104 patients, positive blood cultures were obtained in only 10, nine with a gram stain positive and one with a gram stain negative organism. Sixty-two patients without any evidence of gram positive infection received vancomycin according to the existing algorithm for care of neutropenic fevers. In this population of patients, empiric administration of vancomycin for neutropenic fevers without culture documentation appears to be unnecessary, could be discontinued safely and at substantial cost savings, and might slow the appearance of vancomycin-resistant organisms.

Clostridium difficile infection

Clostridium difficile infection is associated with broad-spectrum antibiotic therapy and is the most common cause of infectious diarrhea in hospital patients. Pathogenic strains of C. difficile produce two protein exotoxins, toxin A and toxin B, which cause colonic mucosal injury and inflammation. Infection may be asymptomatic, cause mild diarrhea, or result in severe pseudomembranous colitis. Diagnosis depends on the demonstration of C. difficile toxins in the stool. The first step in management is to discontinue the antibiotic that caused diarrhea. If diarrhea and colitis are severe or persistent, oral metronidazole is the treatment of choice. Oral vancomycin is also effective, but it is more expensive than metronidazole and its widespread use may encourage the proliferation of vancomycin-resistant nosocomial bacteria. Diarrhea and colitis usually improve within three days after a patient starts taking metronidazole or vancomycin, but 20% suffer a relapse of diarrhea when these agents are discontinued.

Impact of a vancomycin restriction policy on use and cost of vancomycin and incidence of vancomycin-resistant Enterococcus

OBJECTIVE

To review the appropriateness of vancomycin therapy, changes in vancomycin use, and the incidence of vancomycin-resistant Enterococcus (VRE) after implementation of a limited restriction policy requiring approval from the Infectious Diseases Approval service to continue vancomycin therapy beyond 72 hours.

DESIGN

A prospective chart review was conducted in April 1995. Pharmacy billing data and infection control data were compared before and after policy implementation.

SETTING

A 725-bed university teaching institution.

PATIENTS

All patients receiving vancomycin during April 1995.

MAIN OUTCOME MEASURES

Appropriateness of use was based on the Centers for Disease Control and Prevention (CDC) recommendations for prudent vancomycin use.

RESULTS

A total of 333 courses of vancomycin therapy were reviewed. Vancomycin use was appropriate in 219 (66%) courses. Of the 114 courses that did not meet the CDC guidelines, 76 (67%) were for empiric use, 35 (31%) were for prophylactic use, and 3 (3%) were for therapeutic use. Overall, the total number of grams used decreased 9%, grams per 1000 patient-days decreased by 10, and the total number of patients exposed to vancomycin decreased 0.5%. Several services had large decreases in vancomycin use. Vancomycin expenditures decreased by $15788 for the 7-month time period. The incidence of VRE remained unchanged, at 30% of all enterococcal isolates 2 years after policy implementation.

CONCLUSIONS

The limited restriction policy was effective in decreasing the total grams of vancomycin used. However, one-third of vancomycin therapy was inappropriate and the incidence of VRE was unchanged. A more stringent restriction policy could potentially increase appropriate use, further decrease the amount of vancomycin used, and decrease the incidence of VRE.

Epidemiology of vancomycin usage at a children's hospital, 1993 through 1995

OBJECTIVE

To describe the epidemiology of vancomycin usage at a children's hospital.

METHODS

A cohort study of patients at Egleston Children's Hospital who were charged for the receipt of vancomycin from October, 1992, through October, 1995, was performed. Data were obtained from pharmacy charge records in the hospital's medical records information system.

RESULTS

During the study period there were 3589 patient hospitalizations in which vancomycin was used. Patients receiving vancomycin were predominantly male (56.6%) and white (62.4%), ranged in age from 0 to 31 (median, 3.8) years and had an average length of stay of 6.0 days. The total number of vancomycin doses was 105,704; the median number of vancomycin doses during each patient hospitalization was 11.0 (range, 1 to 1215). The total charge for vancomycin used was $2,009,746; the median charge for vancomycin per patient was $297.50 (range, $11 to 19,864). The majority (75.7%) of vancomycin doses were given on the hematology (27.6%), neurosurgery (17.9%), cardiothoracic surgery (13.4%), neonatology (9.7%) or general pediatrics (7.1%) services. Overall surgery service patients were significantly more likely to receive vancomycin than were medicine service patients (1267 doses/6221 admissions vs. 1954/19,446; relative risk, 2.03; P < 0.001). During the study period the number of vancomycin doses decreased significantly (P < 0.001).

CONCLUSIONS

This study shows the value of evaluating antimicrobial use through a pharmacy database. Although vancomycin use decreased during the study period, large amounts of vancomycin are still being prescribed primarily on subspecialty service patients. Interventions to reduce vancomycin use should focus on these groups.

Cost-effectiveness analysis of serum vancomycin concentration monitoring in patients with hematologic malignancies

OBJECTIVE

This study evaluates the cost-effectiveness of vancomycin serum concentration monitoring in patients with hematologic malignancies.

METHODS

The study was designed as a prospective randomized study. Seventy immunocompromised febrile patients with hematologic malignancies were randomly assigned to either a vancomycin therapeutic drug monitoring group (TDM group; n = 37) or to a control group (n = 33). Intervention in the TDM group involved patient follow-up by a clinical pharmacist to obtain and pharmacokinetically interpret serum vancomycin concentrations for dosage individualization.

RESULTS

Evaluation of all patients included global clinical response and nephrotoxicity, as well as the economic costs and effectiveness derived from the vancomycin monitoring program. There were no significant differences between the TDM and control groups in the outcome measures, except for the incidence of nephrotoxicity: the rates of minor nephrotoxicity were 33.3% and 13.5% in the control and TDM groups, respectively. The corresponding figures for moderate nephrotoxicity were 9.1% and 0%. Logistic regression analysis confirmed that TDM independently reduced the incidence of nephrotoxicity in this patient population. On the basis of this reduced nephrotoxicity, a incremental cost of $435 per case of nephrotoxicity prevented was found for vancomycin serum concentration monitoring.

CONCLUSIONS

A decreased incidence of nephrotoxicity provides evidence of a real clinical benefit to patient management in patients with hematologic malignancies. The TDM for vancomycin therapy in this high-risk population has been shown to be a cost-effective procedure.

Pharmacoeconomics: disease-based management applications

Pharmacoeconomic information is rapidly becoming an accepted format for evaluating and comparing various treatment options. Such information may either supplement or replace standard methods for evaluating new drugs for possible inclusion on the formulary. It is important to recognize the pitfalls that may accompany different methods of collecting and evaluating pharmacoeconomic studies. Such information is important because drug use and outcomes in a real-world setting may differ substantially from those within the confines of a clinical trial setting.

Impact of glycopeptide therapy after hospital discharge on inpatient costs: a comparison of teicoplanin and vancomycin

Data were collected prospectively from 59 patients receiving vancomycin and 20 patients receiving teicoplanin. The mean daily drug cost was 52.40 pounds for teicoplanin and 31.13 pounds for vancomycin; the 95% Confidence Intervals (CI) for the difference in mean drug costs varied between 14.40 pounds and 28.10 pounds in favour of vancomycin. Use of a loading dose of teicoplanin significantly increased mean daily drug costs if the duration of treatment was less than 10 days. Costs of preparation, administration and monitoring were consistently higher for vancomycin than for teicoplanin and inclusion of these costs reduced the difference in mean daily costs to 13.01 pounds (95% CI 6.10 to 19.90 pounds). In Dundee 11 of 20 patients who received teicoplanin had received some of their treatment after discharge from the hospital and a survey of UK hospitals confirmed that teicoplanin treatment after discharge is being used in a wide range of conditions. The median proportion of teicoplanin treatment in Dundee given after discharge was 28.4% for each patient who received the drug: the median proportion of non-inpatient therapy was 50% per patient of those who received any teicoplanin treatment after discharge. Assuming that teicoplanin costs 20 pounds per day more than vancomycin, use of teicoplanin implies an investment of 70.42 pounds to gain one hospital day through earlier discharge of patients receiving teicoplanin.

Use of benchmarking techniques to justify the evolution of antibiotic management programs in healthcare systems

OBJECTIVE

To apply basic benchmarking techniques to hospital antibiotic expenditures and clinical pharmacy personnel and their duties, to identify cost savings strategies for clinical pharmacy services.

DESIGN

Prospective survey of 18 hospitals ranging in size from 201 to 942 beds. Each was asked to provide antibiotic expenditures, an overview of their clinical pharmacy services, and to describe the duties of clinical pharmacists involved in antibiotic management activities. Specific information was sought on the use of pharmacokinetic dosing services, antibiotic streamlining, and oral switch in each of the hospitals.

RESULTS

Most smaller hospitals (< 300 beds) did not employ clinical pharmacists with the specific duties of antibiotic management or streamlining. At these institutions, antibiotic management services consisted of formulary enforcement and aminoglycoside and/or vancomycin dosing services. The larger hospitals we surveyed employed clinical pharmacists designated as antibiotic management specialists, but their usual activities were aminoglycoside and/or vancomycin dosing services and formulary enforcement. In virtually all hospitals, the yearly expenses for antibiotics exceeded those of Millard Fillmore Hospitals by $2,000-3,000 per occupied bed. In a 500-bed hospital, this difference in expenditures would exceed $1.5 million yearly. Millard Fillmore Health System has similar types of patients, but employs clinical pharmacists to perform streamlining and/or switch functions at days 2-4, when cultures come back from the laboratory.

CONCLUSIONS

The antibiotic streamlining and oral switch duties of clinical pharmacy specialists are associated with the majority of cost savings in hospital antibiotic management programs. The savings are considerable to the extent that most hospitals with 200-300 beds could readily cost-justify a full-time clinical pharmacist to perform these activities on a daily basis. Expenses of the program would be offset entirely by the reduction in the actual pharmacy expenditures on antibiotics.

Teicoplanin. A pharmacoeconomic evaluation of its use in the treatment of gram-positive infections

Teicoplanin, a glycopeptide antibiotic, is active against Gram-positive organisms, including methicillin-resistant staphylococci. It has demonstrated similar efficacy to vancomycin in the treatment of Gram-positive infections in febrile patients with neutropenia; fewer comparative data are available in patients with other infection types. Compared with vancomycin, teicoplanin is associated with less nephrotoxicity, appears to cause fewer anaphylactoid reactions, requires less monitoring and is more convenient to administer (once daily by intravenous bolus or intramuscular injection vs 2 to 4 times daily by intravenous infusion). Two European cost-minimisation studies have demonstrated that while the acquisition cost per dose of teicoplanin was approximately twice that of vancomycin, the cost of 2 weeks' therapy with either agent was similar (difference of 1 to 2%). However, in order to fully explore potential differences between these agents, a full economic analysis which considers all treatment-related costs is needed. Home therapy of Gram-positive infections, a setting in which teicoplanin may be preferred over vancomycin because of its tolerability profile and ease of administration, is particularly worthy of future economic study. Thus, there are a number of areas needing further study before the optimum formulary positioning of teicoplanin can be definitely stated. Nevertheless, present evidence suggests that teicoplanin is likely to have pharmacoeconomic advantages over vancomycin in at least some situations.

Update on Clostridium difficile-induced colitis, Part 2

Clostridium difficile is a nosocomial pathogen able to survive unfavorable environments by sporulation; when conditions advantageous for rapid growth appear, the vegetative form is regenerated. Lack of conscientious hand washing and failure of health care providers to use disposable gloves facilitate transmission within institutions. Exposure to certain antimicrobials expedites C. difficile overgrowth within the colon by altering the composition of the normal gut microflora. Antineoplastic agents may also precipitate CDIC. The characteristics of the colonizing strain, the properties of the inciting drug, and individual host factors collectively seem to govern the expression of the disorder. Clinical presentations range from self-limiting diarrhea to severe diarrhea accompanied by abdominal pain, fever, and leukocytosis to potentially life-threatening PMC. A preponderance of data supports the interpretation that oral metronidazole and oral vancomycin are therapeutically equivalent for the treatment of all but the most severe cases of CDIC. Whether the two drugs are equivalent in severe CDIC is controversial and will probably remain so in the absence of a well-designed trial to expand on the findings of the study by Teasley et al. Because of the cost difference and therapeutic equivalence, oral metronidazole should be the preferred routine treatment for CDIC; oral vancomycin should be reserved for severe cases and cases that fail to respond to at least six days of oral metronidazole therapy. Another important argument, albeit a hypothetical one, for limiting institutional use of oral vancomycin is to minimize selective environmental pressure for the emergence and dissemination of vancomycin-resistant enterococci. An epidemic outbreak of CDIC caused by clindamycin-resistant C. difficile in an institution where clindamycin use was extremely high illustrates the possible consequences of such selective pressure. Oral metronidazole 250 mg four times daily will usually provide a satisfactory response, but clinicians may wish to consider increasing the total daily dose for some patients who have symptoms like fever and leukocytosis. For oral vancomycin, 125 mg four times daily is sufficient in virtually all circumstances. Ten days of therapy is usually adequate for either drug. CDIC in a patient unable to take medications orally presents a bit of a therapeutic dilemma. Two approaches that appear effective are rectal administration of vancomycin and intravenous administration of metronidazole, although intravenous metronidazole can fail to work, possibly because the colonic concentrations achieved are inadequate. Clinicians may wish to consider a total daily dose of intravenous metronidazole that is at the upper end of the adult dosage range, if this is feasible.(ABSTRACT TRUNCATED AT 400 WORDS)

A pharmacoeconomic model to evaluate antibiotic costs

STUDY OBJECTIVES

To characterize patient sociodemographics and health, describe vancomycin treatment parameters and clinician-rated outcomes, and determine costs associated with treatment including preparation and administration, adverse events, and toxicity.

DESIGN

A prospective study to develop a model for costs associated with antibiotic treatment (vancomycin).

SETTING

A community hospital.

PATIENTS

One hundred adults with active infections.

INTERVENTIONS

Mean duration of therapy was 10 days, and most patients received 2000 mg/day. Serum concentrations were monitored in two of three patients. Detailed cost analyses were completed on a subset of 26 patients selected at random from the overall sample.

MEASUREMENTS AND MAIN RESULTS

Sepsis and skin and skin structure infections were the most common indications for vancomycin therapy. Treatment was effective in 81 patients, failed in 9, and was not evaluable in 10. Thirty-eight percent of patients experienced adverse events attributable to the drug. Phlebitis was common, and red man syndrome, nephrotoxicity, and ototoxicity were infrequent.

CONCLUSIONS

Total cost of vancomycin treatment for 100 patients was $30,251: $23,855 for preparation and administration, $1710 for monitoring serum concentrations, and $4686 for treating adverse reactions. Drug costs accounted for only 55% of the total cost. Vancomycin is safe and effective, but phlebitis is underreported and significantly affects cost.

A vancomycin drug use evaluation and economic analysis in a cancer treatment centre

Princess Margaret Hospital is a 140-bed university affiliated cancer treatment centre. Vancomycin was the only formulary agent available for the treatment of methicillin-resistant gram-positive organisms. The high cost and potential toxicity of this drug warranted a closer examination of its use. The purpose of this study was to evaluate vancomycin use and to determine the economic impact when it was used contrary to newly developed hospital guidelines. A sample of 100 vancomycin orders was randomly selected from all prescriptions filled in 1992. The indication, dose, and duration of therapy for each order were compared against the hospital guidelines. The cost savings associated with altering the sample of prescriptions to meet hospital guidelines were then determined. Nine percent of the prescriptions were for nonapproved indications. The actual dose used did not meet criteria in 32% of cases and the length of therapy was beyond the approved duration in 45% of the orders. If the cases had been altered to meet the guidelines then a total savings of $13,581 would have been realized. The projected savings for the entire year (1992) would have been $100,907. The critical problem areas in vancomycin prescribing were the duration of therapy and dose. The results have provided the impetus to initiate a hospital wide prospective Drug Utilization Evaluation (DUE) study to optimize vancomycin prescribing. The program costs would be easily covered by the expected savings.

Teicoplanin vs vancomycin: cost-effectiveness comparisons

The rising incidence of methicillin-resistant staphylococci and resistant enterococci in recent years has led to increased use of vancomycin as an active combatant in the treatment of gram-positive infections. Teicoplanin is an investigational glycopeptide that shares a similar spectrum of activity with vancomycin and appears to have similar efficacy. Teicoplanin offers several theoretical advantages compared with vancomycin including once-daily dosing, fewer side effects, and the option for intramuscular administration. While these may be perceived as substantial advances in the glycopeptide class of antibiotics, teicoplanin will probably not replace the now generically available vancomycin on hospital formularies. If competitively priced as a once-daily dosing regimen, teicoplanin will likely gain initial acceptance as an alternative in patients with an intolerance to vancomycin infusion-related side effects or in patients placed on combination aminoglycoside therapy for extended periods of treatment, as an intramuscular antibiotic in patients with poor venous access, and for routine antibiotic prophylaxis where protection from resistant gram-positive pathogens is important. The use of teicoplanin in the hospital may become more widespread as its side effect profile and economic advantages of less frequent dosing compared with vancomycin become better understood.

Current treatment of gram-positive infections: focus on efficacy, safety, and cost minimalization analysis of teicoplanin

The current health care environment has had a significant impact on hospital Pharmacy and Therapeutics Committee formulary decisions. In evaluating a new therapy for formulary inclusion, a cost savings along with equivalent or an improvement in patient care and safety is optimal. Teicoplanin is an investigational glycopeptide antimicrobial agent with a spectrum of activity similar to vancomycin. Unlike vancomycin, however, teicoplanin has a long elimination half-life permitting administration once daily, and is well tolerated when given intramuscularly. In addition, teicoplanin is associated with a favorable safety profile. Red man syndrome does not appear to be a significant clinical problem. Results of our cost minimalization analysis using the average acquisition costs of vancomycin revealed that teicoplanin (400 mg), at an average acquisition cost of less than $28.46 when administered intravenously and $30.93 when administered intramuscularly, offers a clinically efficacious, safe, and less expensive alternative to vancomycin therapy.