Switch therapy: the theory and practice of early change from parenteral to non-parenteral antibiotic administration

Annual consumption of parenteral antibiotics in a tertiary hospital of Nepal, 2017-2019: a cross-sectional study

SETTING

Patan Hospital, a tertiary care hospital in Lalitpur District, Nepal.

OBJECTIVES

To describe the annual parenteral antibiotic consumption in 1) defined daily dose (DDD) and DDD per 100 admissions; 2) calculate DDD per 100 admissions and proportions by pharmacological subgroup, chemical subgroup and AWaRe categories; and 3) describe patient expenditure on parenteral antibiotics as a proportion of the total patient expenditure on drugs and consumables between 2017 and 2019.

DESIGN

This was a cross-sectional study.

RESULTS

Total DDD of parenteral antibiotics increased by 23% from 39,639.7 in 2017 to 48,947.7 in 2019. DDD per 100 admissions increased by 10% from 172.1 in 2017 to 190.2 in 2019. Other beta-lactam antibacterials comprised the most frequently consumed pharmacological subgroup. The chemical substance most often consumed was ceftriaxone, with an increasing trend in the consumption of vancomycin and meropenem. Parenteral antibiotics in 'Watch' category were the most consumed over the study period, with a decreasing trend in 'Access' and increasing trend in 'Reserve' categories.

CONCLUSION

We aimed to understand the consumption of parenteral antibiotics at a tertiary care hospital and found that Watch antibiotics comprised the bulk of antibiotic consumption. Overconsumption of antibiotics from the 'Watch' and 'Reserve' categories can promote antimicrobial resistance; recommendations were therefore made for their rational use.

Oral meropenem for superbugs: challenges and opportunities

An increase in the number of multidrug-resistant microbial strains is the biggest threat to global health and is projected to cause >10 million deaths by 2055. The carbapenem family of antibacterial drugs are an important class of last-resort treatment of infections caused by drug-resistant bacteria and are only available as an injectable formulation. Given their instability within the gut and poor permeability across the gut wall, oral carbapenem formulations show poor bioavailability. Meropenem (MER), a carbapenem antibiotic, has broad-spectrum antibacterial activity, but suffers from the above-mentioned issues. In this review, we discuss strategies for improving the oral bioavailability of MER, such as inhibiting tubular secretion, prodrug formulations, and use of nanomedicine. We also highlight challenges and emerging approaches for the development of oral MER.

Is Early Oral Antimicrobial Switch Useful for Less Critically Ill Adults with Community-Onset Bacteraemia in Emergency Departments?

To compare prognoses and adverse events between bacteraemic patients in the emergency department (ED) who received an early antimicrobial IV-to-PO switch and those treated with late or no IV-to-PO switch, an 8-year multicentre cohort consisting of adults with community-onset bacteraemia was conducted. The clinical characteristics and outcomes were compared in matched cohorts by the closest propensity score calculated based on the independent determinants of 30-day mortality identified by the multivariate regression model. Of the 6664 hospitalised patients who received no or late IV-to-PO switch, 2410 were appropriately matched with 482 patients treated with early IV-to-PO switch and discharged from the ED. There were no significant differences between the two matched groups in their baseline characteristics, including the patient demographics, severity and types of comorbidities, severity and sources of bacteraemia, and the 15- and 30-day mortality rates. Notably, in addition to the shorter lengths of intravenous antimicrobial administration and hospital stay, less phlebitis and lower antimicrobial costs were observed in patients who received an early IV-to-PO switch. Similarity was observed in the clinical failure rates between the two groups. Furthermore, the inappropriate administration of empirical antibiotics and inadequate source control were identified as the only independent determinants of the post-switch 30-day crude mortality in patients who received an early IV-to-PO switch. In conclusion, for less critically ill adults with community-onset bacteraemia who received appropriate empirical antimicrobial therapy and adequate source control, an early IV-to-PO switch might be safe and cost-effective after a short course of intravenous antimicrobial therapy.

Electronic Alerts with Automated Consultations Promote Appropriate Antimicrobial Prescriptions

Background

To promote appropriate antimicrobial use in bloodstream infections (BSIs), we initiated an intervention program consisting of electronic alerts and automated infectious diseases consultations in which the identification and antimicrobial susceptibility test (ID/AST) results were reported.

Methods

We compared the appropriateness of antimicrobial prescriptions and clinical outcomes in BSIs before and after initiation of the program. Appropriateness was assessed in terms of effective therapy, optimal therapy, de-escalation therapy, and intravenous to oral switch therapy.

Results

There were 648 BSI episodes in the pre-program period and 678 in the program period. The proportion of effective, optimal, and de-escalation therapies assessed 24 hours after the reporting of the ID/AST results increased from 87.8% (95% confidence interval [CI] 85.5–90.5), 64.4% (95% CI 60.8–68.1), and 10.0% (95% CI 7.5–12.6) in the pre-program period, respectively, to 94.4% (95% CI 92.7–96.1), 81.4% (95% CI 78.4–84.3), and 18.6% (95% CI 15.3–21.9) in the program period, respectively. Kaplan-Meier analyses and log-rank tests revealed that the time to effective (p<0.001), optimal (p<0.001), and de-escalation (p = 0.017) therapies were significantly different in the two periods. Segmented linear regression analysis showed the increase in the proportion of effective (p = 0.015), optimal (p<0.001), and de-escalation (p = 0.010) therapies at 24 hours after reporting, immediately after program initiation. No significant baseline trends or changes in trends were identified. There were no significant differences in time to intravenous to oral switch therapy, length of stay, and 30-day mortality rate.

Conclusion

This novel form of stewardship program based on intervention by infectious disease specialists and information technology improved antimicrobial prescriptions in BSIs.

Switch over from intravenous to oral therapy: A concise overview

Majority of the patients admitted to a hospital with severe infections are initially started with intravenous medications. Short intravenous course of therapy for 2-3 days followed by oral medications for the remainder of the course is found to be beneficial to many patients. This switch over from intravenous to oral therapy is widely practiced in the case of antibiotics in many developed countries. Even though intravenous to oral therapy conversion is inappropriate for a patient who is critically ill or who has inability to absorb oral medications, every hospital will have a certain number of patients who are eligible for switch over from intravenous to oral therapy. Among the various routes of administration of medications, oral administration is considered to be the most acceptable and economical method of administration. The main obstacle limiting intravenous to oral conversion is the belief that oral medications do not achieve the same bioavailability as that of intravenous medications and that the same agent must be used both intravenously and orally. The advent of newer, more potent or broad spectrum oral agents that achieve higher and more consistent serum and tissue concentration has paved the way for the popularity of intravenous to oral medication conversion. In this review, the advantages of intravenous to oral switch over therapy, the various methods of intravenous to oral conversion, bioavailability of various oral medications for the switch over program, the patient selection criteria for conversion from parenteral to oral route and application of intravenous to oral switch over through case studies are exemplified.

Improving quinolone use in hospitals by using a bundle of interventions in an interrupted time series analysis

The objectives of the present study were to determine the effects of multiple targeted interventions on the level of use of quinolones and the observed rates of resistance to quinolones in Escherichia coli isolates from hospitalized patients. A bundle consisting of four interventions to improve the use of quinolones was implemented. The outcome was measured from the monthly levels of use of intravenous (i.v.) and oral quinolones and the susceptibility patterns for E. coli isolates from hospitalized patients. Statistical analyses were performed using segmented regression analysis and segmented Poisson regression models. Before the bundle was implemented, the annual use of quinolones was 2.7 defined daily doses (DDDs)/100 patient days. After the interventions, in 2007, this was reduced to 1.7 DDDs/100 patient days. The first intervention, a switch from i.v. to oral medication, was associated with a stepwise reduction in i.v. quinolone use of 71 prescribed daily doses (PDDs) per month (95% confidence interval [CI] = 47 to 95 PDDs/month, P < 0.001). Intervention 2, introduction of a new antibiotic guideline and education program, was associated with a stepwise reduction in the overall use of quinolones (reduction, 107 PDDs/month [95% CI = 58 to 156 PDDs/month). Before the interventions the quinolone resistance rate was increasing, on average, by 4.6% (95% CI = 2.6 to 6.1%) per year. This increase leveled off, which was associated with intervention 2 and intervention 4, active monitoring of prescriptions and feedback. Trends in resistance to other antimicrobial agents did not change. This study showed that the hospital-wide use of quinolones can be significantly reduced by an active policy consisting of multiple interventions. There was also a stepwise reduction in the rate of quinolone resistance associated with the bundle of interventions.

Outcomes of early switching from intravenous to oral antibiotics on medical wards

Objectives

To evaluate outcomes following implementation of a checklist with criteria for switching from intravenous (iv) to oral antibiotics on unselected patients on two general medical wards.

Methods

During a 12 month intervention study, a printed checklist of criteria for switching on the third day of iv treatment was placed in the medical charts. The decision to switch was left to the discretion of the attending physician. Outcome parameters of a 4 month control phase before intervention were compared with the equivalent 4 month period during the intervention phase to control for seasonal confounding (before–after study; April to July of 2006 and 2007, respectively): 250 episodes (215 patients) during the intervention period were compared with the control group of 176 episodes (162 patients). The main outcome measure was the duration of iv therapy. Additionally, safety, adherence to the checklist, reasons against switching patients and antibiotic cost were analysed during the whole year of the intervention (n = 698 episodes).

Results

In 38% (246/646) of episodes of continued iv antibiotic therapy, patients met all criteria for switching to oral antibiotics on the third day, and 151/246 (61.4%) were switched. The number of days of iv antibiotic treatment were reduced by 19% (95% confidence interval 9%–29%, P = 0.001; 6.0–5.0 days in median) with no increase in complications. The main reasons against switching were persisting fever (41%, n = 187) and absence of clinical improvement (41%, n = 185).

Conclusions

On general medical wards, a checklist with bedside criteria for switching to oral antibiotics can shorten the duration of iv therapy without any negative effect on treatment outcome. The criteria were successfully applied to all patients on the wards, independently of the indication (empirical or directed treatment), the type of (presumed) infection, the underlying disease or the group of antibiotics being used.

Evaluation of an algorithm for switching from IV to PO therapy in clinical practice in patients with community-acquired pneumonia

BACKGROUND

In patients with community-acquired pneumonia (CAP), switching from IV to PO antibiotics offers advantages over IV therapy alone, including improved cost-effectiveness through reductions in the length of hospital stay and treatment costs.

OBJECTIVE

The aim of this study was to determine whether a method for switching therapy in clinical practice could be used in patients with CAP and whether differences were found in the duration of IV treatment and length of hospital stay between the 5 risk classes of the Pneumonia Severity Index (PSI) after the therapy switch.

METHODS

This was a prospective, observational study of patients aged >/=18 years presenting with CAP at our teaching hospital between December 1998 and November 2000. Microbiological and serological tests were performed, and signs and symptoms of CAP, C-reactive protein levels, and white blood cell counts were assessed throughout treatment and at the 1-month follow-up. Patients were stratified by PSI risk class. When the patient's temperature had been normalized for 72 hours and respiratory symptoms (dyspnea, coughing, and thoracal pain) had improved, patients were switched from IV to PO therapy (same drug).

RESULTS

The study included 180 patients with CAP Clinical cure was seen in 174 (97%) patients. No significant difference between the 5 risk classes was found in duration of therapy. Patients in risk class V remained hospitalized for a significantly longer period than patients in risk classes I through IV (P < 0.001). Furthermore, after patients were switched to PO antibiotics, the level of C-reactive protein decreased in patients in all risk classes and was normalized by follow-up.

CONCLUSIONS

In the population studied, use of specific criteria (ie, absence of fever for 72 hours and reduction in respiratory symptoms) allowed successful switch from IV to PO antibiotic therapy for the treatment of CAP Duration of therapy was not affected by PSI risk class, but those in risk class V were hospitalized longer than other risk classes.

Bioavailability of gatifloxacin by gastric tube administration with and without concomitant enteral feeding in critically ill patients

OBJECTIVE

Sequential intravenous-to-oral antimicrobial therapy with highly bioavailable antiinfective agents such as the fluoroquinolones may improve patient safety and decrease cost of infection management. However, physiologic changes associated with critical illness may alter drug absorption, distribution, and clearance, and concomitant enteral feeding may decrease fluoroquinolone bioavailability. We evaluated the effect of critical illness and concomitant gastric tube feeding on gatifloxacin bioavailability.

DESIGN

Prospective, randomized, single-dose, two-way crossover, pharmacokinetic study. SETTINGA tertiary, level-one, trauma center.

PATIENTS

Sixteen critically ill patients (baseline Acute Physiology and Chronic Health Evaluation II score >or=16) tolerating enteral nutrition administered by gastric tube (NG) for >or=12 hrs were randomized to receive gatifloxacin concurrently with continuous tube feeding or with interrupted tube feeds. Patients with renal insufficiency or those receiving concomitant fluoroquinolone therapy or postpyloric feeding were excluded. Patients received gatifloxacin 400 mg either by the intravenous or NG route followed by the alternative dosage form after a 72-hr washout period.

MEASUREMENTS AND MAIN RESULTS

Serial serum gatifloxacin concentrations (from 5 mins to 24 hrs) were analyzed using a validated high-performance liquid chromatography method. Bioavailability was determined as the ratio of NG/intravenous area under the concentration-time curve (AUC infinity ) measured by the trapezoidal method. Although there was no difference in the bioavailability between NG (AUC infinity : 38.0 [range 20.1 to 48.5] microg x h/mL) and intravenous (AUC infinity : 39.5 [range 24.1 to 63.1] microg x h/mL, p =.60) gatifloxacin (bioavailability: 98.5% [range 61.1% to 119.7%]), a wide variability was observed in three of eight patients (>30% reduction in bioavailability). Concomitant gastric tube feeding did not affect gatifloxacin bioavailability (interrupted tube feeds: 98.5% [range 61.1% to 119.7%]; continuous tube feeding: 109.0% [range 86.2% to 142.1%]; p =.42). Neither a period nor differential carryover effect was observed.

CONCLUSIONS

Although concomitant tube feeding did not affect gatifloxacin bioavailability, critical illness resulted in significant variability that may complicate the role of gatifloxacin in sequential intravenous-to-oral therapy. More research is needed to identify those patients in whom gatifloxacin bioavailability is reduced and for whom an empirical increase in gatifloxacin dose should be considered.

Sequential antibiotic therapy for cost containment in the hospital setting: why not?

Antibiotic cost represents a significant part of hospital budgets all over the world. Restriction policies, however and other similar programmes intervening in antimicrobial prescribing have not always been successful in lowering antibiotic expenditure. Timely switch or sequential therapy from initial intravenous to subsequent equivalent oral treatment has been implemented in many institutions for the same purpose. Using strict criteria for optimum patient selection, switch therapy has been proven both effective as antimicrobial treatment and cost saving. As healthcare resources remain lower than needed, cost-saving policies become very desirable. Thus, switch therapy is expected to be more widely used, since it is a cost containing policy which does not compromise treatment outcome.

Place of parenteral cephalosporins in the ambulatory setting: clinical evidence

During the last decade, 6 parenteral third generation cephalosporins have been introduced into clinical practice. The three most frequently used agents are cefotaxime, ceftazidime and ceftriaxone. Although primarily used in hospitals, these agents are increasingly employed in the ambulatory setting. In particular, ceftriaxone, because of its favourable pharmacokinetic profile allowing once-daily administration by a bolus injection, has demonstrated both tolerability and efficacy in the ambulatory setting during extensive worldwide use. Sophisticated parenteral infusion systems enable cephalosporins that require more frequent administration to be delivered in this setting. In noncomparative studies involving a range of patient populations and serious infections (mostly bone, joint and soft tissue, and pneumonia and febrile episodes in neutropenia), these cephalosporins achieved equivalent efficacy and tolerability, and considerable cost savings, since patients were able to receive all or part of their treatment in the home or outpatient setting. However, more comparative studies of ambulatory parenteral therapy in the inpatient setting or ambulatory oral therapy are necessary to further clarify the true cost effectiveness of this type of healthcare delivery. This is increasingly relevant in countries where parenteral antimicrobials are not the 'standard of care' in managing many serious infections. Published experience to date confirms that third generation cephalosporins, particularly ceftriaxone, should have an essential place in the therapeutic formulary of any ambulatory parenteral antibiotic programme.

Strategies for study of the role of cycling on antimicrobial use and resistance

Resistant bacteria usually are seen first in the intensive care unit and other acute-care areas. Thus, strategies to control these organisms often are first tested in these healthcare settings. Frequent among these strategies are attempts to improve antimicrobial use. One proposed method to decrease resistance in special settings like the intensive care unit is the cycling or rotation of antimicrobials. This intervention must be evaluated in the context of other concomitant attempts to improve antimicrobial usage and must take into account other factors influencing resistance. Until such studies are done, the value of cycling and other efforts to limit prescribers' choices of drugs in endemic settings will be unclear. Studies to evaluate cycling will have to be of large scale to produce useful data. It is unlikely that many hospitals or healthcare systems will have sufficient resources on their own to develop studies of sufficient power to be applied widely. Thus, cooperative studies to provide data on this important issue should be an international priority.

Early switch from intravenous to oral antibiotics: guidelines and implementation in a large teaching hospital

In recent years 'switch therapy' has been advocated: short intravenous antibiotic therapy, for 2-3 days, followed by oral treatment for the remainder of the course. Little is known about the number of patients that could benefit from early switch therapy and the consequences of introducing this strategy in everyday practice. We prospectively registered all antibiotic courses on wards for Internal Medicine, Surgery, and Pulmonology during a 2 month period, before (n = 362, inventorial phase) and after (n = 281, implementation phase) the introduction of guidelines for switching therapy. Approximately 40% of all patients who started on iv antibiotics were candidates for an early iv-oral switch. During the inventorial phase, 54% (52/97) of eligible patients were switched to oral treatment, after a median of 6 days (range 2-28 days). After implementation of the guidelines, this percentage rose to 83% (66/80) (difference 29%, 95% CI 16-42%; P < 0.001). Therapy was also switched earlier, after a median of 4 days (range 2 to 16 days). In the 6 weeks after completion of the oral course, recurrence of infections, or readmissions due to reinfections did not occur. Compared with the inventorial phase, 43% of iv administrations could be avoided, that is >6000 per year. This means a potential annual reduction of dfl.60,000 (c. US$30,000) of administration costs. The potential savings in purchase costs of the antibiotics were dfl.54,000 (US$27,000) annually. In conclusion, a substantial number of patients starting on iv antibiotics were candidates for an early iv-oral switch. The guidelines were well accepted by the physicians and substantial savings in costs and nursing time were achieved.

Implementation of sequential therapy programmes--a pharmacist's view

Sequential antibiotic therapy has a number of advantages in terms of patient benefit and value for money in drug use. Introduction and maintenance of a process to ensure sequential therapy is multidisciplinary, involving clinicians, pharmacists, microbiologists and possibly nurses. The contribution of pharmacists is multi-faceted and involves senior and junior pharmacists working in a number of areas. Pharmacy managers will be involved at policy setting level through the Drug and Therapeutics committee and similar bodies. Purchasing and formulary pharmacists will be involved in negotiating purchasing agreements while clinical pharmacists provide data on the costs and outcomes of treatment. The drug information pharmacist is a valuable resource in searching and interpreting the available literature. Whatever system is used, clinical pharmacists have an important role in identifying patients and monitoring prescribing. In many schemes described in the literature, pharmacists have had an important role in auditing the effectiveness of sequential therapy. There may be scope for developing the clinical pharmacist's role further by devolving, under protocol, increased decision making and medicines management responsibilities.

Sequential antimicrobial therapy: comparison of the views of microbiologists and pharmacists

Sequential antimicrobial therapy (SAT) is arousing keen interest in microbiologists and pharmacists. In an attempt to obtain information from these groups regarding the use of SAT in hospitals, an anonymized postal survey was carried out. A SAT questionnaire was circulated to consultant medical microbiologists, clinical microbiologists, and heads of pharmacy departments within the British Isles. Four hundred and forty-seven microbiologists and pharmacists returned completed questionnaires, giving a response rate of 29%. Just over half of medical microbiologists (MM) and pharmacists (PH) indicated that SAT was used in their institution in respiratory medicine, geriatrics, surgery and, significantly, to a lesser degree in paediatrics. The most common infections treated were pneumonia, bronchitis and wound infection. However, there were significant differences between MM and PH, with MM favouring greater use of SAT in peritonitis (P=0.03), septicaemia (P<0.01), bone infection (P<0.01), pyelonephritis (UTI) (P<0.01), and PH favouring use in bronchitis (P<0.01). The ability to take oral fluids or a recognition of no potential absorption problems were key criteria in the decision process leading to the institution of SAT by MM and PH. Significantly more MM favoured employing criteria such as temperature <38 degrees C (P<0.01), no requirement for high tissue concentrations (P=0.02) and evidence of response to i.v. antimicrobial therapy (P<0.01) than PH. The most frequently "switched" antimicrobials were metronidazole, ciprofloxacin and co-amoxiclav. There were more than five times as many MM reporting the use of clindamycin than PH (P<0.01), whereas nearly twice as many PH cited use of cefuroxime (P<0.01). Of those hospitals not employing SAT, most MM and PH concurred that the commonest reason to institute SAT was financial, followed by convenience to patients and staff. However, more PH than MM indicated that protocols (P<0.01) and a reduction in i.v. complications (P<0.01) were important to them. In promoting SAT, MM and PH felt they had the major role. Significantly, each profession felt that the other had a lesser role to play; MM as judged by the PH (P<0.01) and PH as judged by MM (P<0.01). When promoting SAT, both MM and PH felt that "education for clinicians" followed by regular audit was the best way to ensure implementation. However, significant differences arose with PH regarding nurse education (P<0.01), SAT posters (P=0.02), regular review of patients (P=0.04) and patient's notes SAT stickers (P<0.01) as more important to them than MM. Significantly, less MM than PH (P<0.01) insisted that either the i.v. and PO antimicrobials were identical or were from the same group or class when "switching". This survey highlights interesting comparisons between the approaches of MM and PH towards SAT and may indicate ways in which both groups may work together to bring about change.

Sequential antimicrobial therapy: pharmacokinetic and pharmacodynamic considerations in sequential therapy

The pharmacodynamic factors important in sequential therapy are largely unknown. This is because most pharmacodynamic investigations concentrate on how bacterial populations respond to first antimicrobial exposures. However, it is likely that for B lactams T>MIC and for quinolones the antimicrobial AUC/MIC ratio will be important. Factors which reduce antimicrobial absorption will impact on these parameters and require further study.

Sequential switch therapy for lower respiratory tract infections: a European perspective

Traditionally, serious lower respiratory tract infections (LRTIs) are treated in hospital and with parenteral antibiotics. During the past decade, there has been an impetus to reduce the overall cost of antimicrobial therapy. The availability of new oral antibiotics with superior pharmacokinetics profiles and safety has enabled clinicians increasingly to consider their use in managing serious infections effectively. This article reviews the current published literature regarding the practice of switch therapy for LRTIs, examining the evidence for efficacy, safety, appropriate timing of the switch, the economic benefits, and the suitability of various antibiotics. There is an emphasis on comparing current European and US experience and examining key strategies in implementing such programs and means of assessing their impact.