Stability of Ampicillin plus Ceftriaxone Combined in Elastomeric Infusion Devices for Outpatient Parenteral Antimicrobial Therapy

[Translated article] Retrospective study of home antibiotic infusion therapy using elastomeric infusion pumps

OBJECTIVES

To describe the experience of home antibiotic infusion therapy using elastomeric infusion pumps, administered to patients admitted to the Home Hospitalisation Unit of a tertiary hospital for 3 years and to analyse clinical evolution and mortality.

METHOD

Retrospective observational study. The medical history of the patients included in the study was reviewed. Information was obtained on personal history, antimicrobial therapy received, and clinical evolution. Statistical analysis was performed using SPSS® 19 software.

RESULTS

81 patients were included, 61.7% men, with a mean age of 73.5±17.5 years. The most frequent comorbidities were diabetes mellitus (30.9%) and chronic kidney disease (28.4%). Patients received a mean of 11.9±8.5 days of antibiotic treatment in an elastomeric infusion pump. The main focus of infection was respiratory (27.2%), followed by bacteremia (16%) and skin and soft tissue infections (12.3%). Of the infections, 65.4% were monomicrobial, with Pseudomonas aeruginosa being the main microorganism involved (39.6%). The most commonly used antimicrobial was piperacillin/tazobactam (33.3%). The clinical course was good in 85.2% of the patients, but the mortality rate in the 30 days following the end of treatment was 24.7%. In the univariate analysis, a history of neoplasia in the last 5 years (p=.01) and having received fewer days of antibiotic therapy prior to the start of outpatient antimicrobial therapy in infusion pump (p=.04) were associated with worse clinical outcome. Age over 80 years was associated with better outcome (p=.03). The diagnosis of heart failure was associated with higher mortality (p=.026) and patients from surgical services, with lower mortality (p=.047). In the multivariate analysis, the presence of neoplasia was associated with unfavourable evolution (p=.012) and heart failure with higher mortality (p=.027).

CONCLUSIONS

Outpatient antimicrobial therapy in elastomeric infusion pumps is an alternative in patients requiring prolonged intravenous treatment, and age is not a conditioning factor for inclusion in these programs. However, the presence of certain comorbidities can negatively affect the clinical course and mortality of patients.

Retrospective study of home antibiotic infusion therapy in elastomeric infusion pumps

OBJECTIVES

To describe the experience of home antibiotic infusion therapy using elastomeric infusion pumps, administered to patients admitted to the Home Hospitalization Unit of a tertiary hospital for three years and to analyse clinical evolution and mortality.

METHOD

Retrospective observational study. The medical history of the patients included in the study was reviewed. Information was obtained on personal history, antimicrobial therapy received and clinical evolution. Statistical analysis was performed using SPSS® 19 software.

RESULTS

Eighty-one patients were included, 61.7% men, with a mean age of 73.5 ± 17.5 years. The most frequent comorbidities were diabetes mellitus (30.9%) and chronic kidney disease (28.4%). Patients received a mean of 11.9 ± 8.5 days of antibiotic treatment in an elastomeric infusion pump. The main focus of infection was respiratory (27.2%), followed by bacteremia (16%) and skin and soft tissue infections (12.3%). Of the infections, 65.4% were monomicrobial, with Pseudomonas aeruginosa being the main microorganism involved (39.6%). The most commonly used antimicrobial was piperacillin/tazobactam (33.3%). The clinical course was good in 85.2% of the patients, but the mortality rate in the 30 days following the end of treatment was 24.7%. In the univariate analysis, a history of neoplasia in the last 5 years (p = 0.01) and having received fewer days of antibiotic therapy prior to the start of outpatient antimicrobial therapy in infusion pump (p = 0.04) were associated with worse clinical outcome. Age over 80 years was associated with better outcome (p = 0.03). The diagnosis of heart failure was associated with higher mortality (p = 0.026) and patients from surgical services, with lower mortality (p = 0.047). In the multivariate analysis, the presence of neoplasia was associated with unfavorable evolution (p = 0.012) and heart failure with higher mortality (p = 0.027).

CONCLUSIONS

Outpatient antimicrobial therapy in elastomeric infusion pumps is an alternative in patients requiring prolonged intravenous treatment, and age is not a conditioning factor for inclusion in these programs. However, the presence of certain comorbidities can negatively affect the clinical course and mortality of patients.

Ampicillin Stability in a Portable Elastomeric Infusion Pump: A Step Forward in Outpatient Parenteral Antimicrobial Therapy

Outpatient parenteral antimicrobial therapy (OPAT) with continuous infusion pumps is postulated as a very promising solution to treat complicated infections, such as endocarditis or osteomyelitis, that require patients to stay in hospital during extended periods of time, thus reducing their quality of life and increasing the risk of complications. However, stability studies of drugs in elastomeric devices are scarce, which limits their use in OPAT. Therefore, we evaluated the stability of ampicillin in sodium chloride 0.9% at two different concentrations, 50 and 15 mg/mL, in an elastomeric infusion pump when stored in the refrigerator and subsequently in real-life conditions at two different temperatures, 25 and 32 °C, with and without the use of a cooling device. The 15 mg/mL ampicillin is stable for up to 72 h under refrigeration, allowing subsequent dosing at 25 °C for 24 h with and without a cooling device, but at 32 °C its concentration drops below 90% after 8 h. In contrast, 50 mg/mL ampicillin only remains stable for the first 24 h under refrigeration, and subsequent administration at room temperature is not possible, even with the use of a cooling system. Our data support that 15 mg/mL AMP is suitable for use in OPAT if the volume and rate of infusion are tailored to the dosage needs of antimicrobial treatments.

Treatment of Enterococcus faecalis Infective Endocarditis: A Continuing Challenge

Today, Enterococcus faecalis is one of the main causes of infective endocarditis in the world, generally affecting an elderly and fragile population, with a high mortality rate. Enterococci are partially resistant to many commonly used antimicrobial agents such as penicillin and ampicillin, as well as high-level resistance to most cephalosporins and sometimes carbapenems, because of low-affinity penicillin-binding proteins, that lead to an unacceptable number of therapeutic failures with monotherapy. For many years, the synergistic combination of penicillins and aminoglycosides has been the cornerstone of treatment, but the emergence of strains with high resistance to aminoglycosides led to the search for new alternatives, like dual beta-lactam therapy. The development of multi-drug resistant strains of Enterococcus faecium is a matter of considerable concern due to its probable spread to E. faecalis and have necessitated the search of new guidelines with the combination of daptomycin, fosfomycin or tigecycline. Some of them have scarce clinical experience and others are still under investigation and will be analyzed in this review. In addition, the need for prolonged treatment (6–8 weeks) to avoid relapses has forced to the consideration of other viable options as outpatient parenteral strategies, long-acting administrations with the new lipoglycopeptides (dalbavancin or oritavancin), and sequential oral treatments, which will also be discussed.