Characteristics of gram-negative urinary tract infections caused by extended spectrum beta lactamases: pivmecillinam as a treatment option within South Dublin, Ireland

Safety, pharmacokinetics, and food-effect of pivmecillinam after single- and multiple-dose in healthy Chinese subjects: a phase I study

Urinary tract infection (UTI) is one of the most prevalent bacterial infectious diseases worldwide. However, the resistance of urinary pathogens to other UTI antibiotics such as trimethoprim and trimethoprim/sulphamethoxazole increased. Pivmecillinam is a prodrug of mecillinam, which is effective for the treatment of urinary tract infections. The purpose of this study was to assess the safety, and pharmacokinetics of pivmecillinam and mecillinam after single- and multiple-dose oral administration of pivmecillinam tablets in healthy Chinese subjects. The study also investigated the profile of urinary excretion of mecillinam, as well as the effect of food and gender on the pharmacokinetics of pivmecillinam and mecillinam. This study was a single-center, open-label phase I study carried out in three groups. In total, 34 subjects were included in the study: group 1-food effect study with pivmecillinam 200 mg (n = 12); group 2-single- and multiple-dose study with pivmecillinam 400 mg (n = 12); group 3-single dose study with pivmecillinam 600 mg (n = 10). The plasma and urine concentrations of pivmecillinam and mecillinam were measured, and their pharmacokinetics were calculated. Treatment-emergent adverse events were evaluated and recorded in safety assessments for three groups. No severe adverse events were found in this study. After a single dose of pivmecillinam was taken orally, the maximum plasma concentration (Cmax) and the area under the concentration-time curve (AUC) of pivmecillinam increased in a dose-proportional manner, nor did mecillinam. Food had significant effects on Cmax and AUC0-t of pivmecillinam and Cmax of mecillinam. The mean cumulative percentage of urine excretion of mecillinam at 0 to 24 h ranged from 35.5 to 44.0%. Urinary cumulative excretion is relative to the drug dose, but the diet and multiple-dose administration did not affect the urinary cumulative excretion rate. The safety and pharmacokinetics of pivmecillinam and mecillinam after single- (200/400/600 mg) or multiple-dose (400 mg) administration were demonstrated in healthy Chinese subjects. Food affected the pharmacokinetics of pivmecillinam and mecillinam.

Activity of mecillinam against USA urinary tract clinical isolates from 2017 to 2020 including isolates resistant to comparator antibiotics

OBJECTIVES

To support the clinical development of mecillinam and pivmecillinam in the United States for the treatment of complicated and uncomplicated urinary tract infections (UTIs), this study investigated the activity of mecillinam compared with other antibiotics against Enterobacterales isolates from patients with UTIs in the United States during 2017 to 2020. Mecillinam is a first-in-class amidinopenicillin antibiotic, being the only β-lactam to exert its antibacterial activity through exclusive binding to penicillin-binding protein 2. Pivmecillinam is the oral prodrug of mecillinam and is recommended as a first-line therapy by the Infectious Disease Society of America guidelines for uncomplicated UTIs and is approved for the treatment of uncomplicated UTIs in Europe, Canada, and the United States.

METHODS

A total of 3303 isolates were collected and antimicrobial susceptibility determined according to Clinical Laboratory and Standards Institute (CLSI) guidelines.

RESULTS

Susceptibility was highest for fosfomycin (97.1% susceptible) and mecillinam (94.9% susceptible). Against extended-spectrum beta-lactamase (ESBL)-positive bacteria susceptibilities were highest for mecillinam (98.2% susceptible) and fosfomycin (97.3% susceptible) and against ESBL-positive K. pneumoniae only mecillinam and fosfomycin had > 80% susceptibility. Resistance to comparator antibiotics was highest for trimethoprim-sulfamethoxazole (27.1%), followed by ciprofloxacin (19.3%), ceftriaxone (19.2%), and nitrofurantoin (12.1%). Multi-drug-resistant isolates were most susceptible to mecillinam and fosfomycin.

CONCLUSION

The data further support the clinical development and clinical utility of mecillinam. © 2024 The Author(s). Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy.

Review of the In Vitro Microbiological Activity of Mecillinam Against Common Uropathogens in Uncomplicated Urinary Tract Infection: Focus on Resistant Pathogens

Antimicrobial resistance in uropathogens commonly causing urinary tract infections (UTIs) is a growing problem internationally. Pivmecillinam, the oral prodrug of mecillinam, has been used for over 40 years, primarily in Northern Europe and Canada. It is recommended in several countries as a first-line agent for the treatment of uncomplicated UTIs (uUTIs) and is now approved in the United States. We performed a structured literature search to review the available evidence on susceptibility of common uUTI-causing uropathogens to mecillinam. Among 38 studies included in this literature review, susceptibility rates for Escherichia coli to mecillinam-including resistant phenotypes such as extended-spectrum β-lactamase-producing E. coli-exceed 90% in most studies. High rates of susceptibility were also reported among many other uropathogens including Klebsiella spp., Enterobacter spp., and Citrobacter spp. In the current prescribing climate within the United States, pivmecillinam represents a viable first-line treatment option for patients with uUTI.

General practitioners' clinical practice on the management of cystitis in Normandy, France: A clinical vignettes-based study

RATIONALE, AIMS, AND OBJECTIVES

The objective was to measure the quality of clinical practice for the management of cystitis in adult women in general practice by collaborating with quality circles and the regional centre for antibiotic counsel.

METHOD

This descriptive cross-sectional study was performed in 2018 in Normandy, France. A questionnaire composed of clinical vignettes was used to evaluate practices of general practitioners (GPs) with regard to cystitis classified into four categories: simple, at risk of complication, recurrent, and caused by multidrug-resistant bacteria. The 2017 French Infectious Diseases Society's guidelines were used as a reference.

RESULTS

A total of 142 GPs participated in the study (45.5% of the solicited). Fosfomycin-trometamol and pivmecillinam were cited as first-line treatments for simple cystitis by 134 (94%) and 38 (27%) participants, respectively. For at risk of complication cystitis, the treatments cited were cefixime by 64 participants (45%), ofloxacin by 50 (35%), pivmecillinam by 49 (35%), fosfomycin-trometamol by 38 (27%), nitrofurantoin by 36 (25%), and amoxicillin-clavulanic acid by 28 (20%). Mean compliance rates were 85% for simple cystitis, 39% for at risk of complication cystitis, 60% for recurrent cystitis and 14% for cystitis caused by multidrug-resistant bacteria. Two criteria had less than 10% of the compliant answers: comprehensive knowledge of cystitis complication risk factors (9%) and positivity thresholds of urine cultures (10%).

CONCLUSIONS

In this study, diagnostic means, follow-up testing, and simple cystitis treatment (with fosfomycin predominantly mentioned) were broadly compliant. The use of critical antibiotics was too frequent for at risk of complication cystitis. There may be a need to improve the knowledge of professionals on antibiotic resistance and appropriate antibiotic use.

Microbial risk factors for treatment failure of pivmecillinam in community-acquired urinary tract infections caused by ESBL-producing Escherichia coli

The aim of this study was to identify microbial risk factors for treatment failure of pivmecillinam in community-acquired urinary tract infections (ca-UTIs) caused by ESBL-producing Escherichia coli. Eighty-nine ESBL-producing E. coli isolated from women suffering from ca-UTIs were included. The susceptibilities to mecillinam were determined using MIC gradient strip. Whole genome sequencing was performed on a MiSeq platform, and genome assembly was performed using SPAdes v3.11.0. Neither mecillinam MICs nor ESBL genotypes were associated with treatment outcome of patients treated with pivmecillinam. Specific STs, however, showed significant differences in treatment outcome. Patients infected with ST131 were more likely to experience treatment failure compared to patients infected with non-ST131 (p 0.02) when adjusted for pivmecillinam dose, mecillinam MIC and severity of infection. Patients infected with ST69 were more often successfully treated compared to patients infected with non-ST69 (p 0.04). Patients infected with bla_CTX-M-15 ST131 strains were more likely to experience treatment failure than those infected with non-bla_CTX-M-15 ST131 strains (p 0.02). The results suggest that specific STs are associated with the clinical efficacy of pivmecillinam. Further studies with a larger number of strains, including a larger number of mecillinam resistant strains, are needed to confirm these results.

Emerging clinical role of pivmecillinam in the treatment of urinary tract infections caused by Extended Spectrum βeta-lactamase (ESBL) producing Enterobacteriaceae

BACKGROUND

Extended Spectrum βeta-lactamase (ESBL)-producing Enterobacteriaceae causing urinary tract infections (UTIs) appear resistant to many common oral agents. There is a growing need to discover new antibiotics to combat with emerging antibiotic resistance problem. Until the discovery of new antimicrobials, we can bring back forgotten antibiotics to our clinical formulary. Pivmecillinam (prodrug of mecillinam), an oral antimicrobial agent is effective against ESBL producing organisms. We analysed the sensitivity rates of ESBL-producing Enterobacteriaceae from urine samples to mecillinam and to document if pivmecillinam is a suitable alternative option in the treatment of UTI.

MATERIALS/METHODS

This retrospective study was conducted from September 2015 to September 2017. Data were collected from the pathology information system. Antimicrobial sensitivity testing on ESBL-producing Enterobacteriaceae isolates was carried out by disc diffusion method in accordance with The European Committee on Antimicrobial Susceptibility Testing.

RESULTS

A total of 986 ESBL-producing Enterobacteriaceae were tested for mecillinam during the study period. Of 986 organisms, Escherichia coli was the most common organism (889); followed by Klebsiella species (71) and others Enterobacteriaceae (26). Mecillinam sensitivity was found in 96% Escherichia coli (855/889 isolates), 83% Klebsiella species (59/71 isolates) and 88% other Enterobacteriaceae (23/26 isolates). Overall 95% (935/986 isolates) of ESBL-producing urinary isolates were sensitive to mecillinam.

CONCLUSIONS

Pivmecillinam appears to be suitable option to treat ESBL-producing Enterobacteriaceae causing uncomplicated UTI. Our results showed low resistance rate to mecillinam. We recommend the use of pivmecillinam in uncomplicated UTIs because of ESBL-producing Enterobacteriaceae. More studies on in vitro activity of mecillinam against ESBL producing organism and its use and clinical outcome should be tried in future.

Mecillinam for the treatment of acute pyelonephritis and bacteremia caused by Enterobacteriaceae: a literature review

Purpose

The pharmacokinetic properties of mecillinam (MEC) for urinary tract infections are excellent, and the resistance rate in Enterobacteriaceae is low compared to other recommended antibiotics. The oral prodrug pivmecillinam (P-MEC) has been used successfully as first choice for cystitis in the Nordic countries for many years. Norwegian and Danish guidelines also recommend P-MEC for acute uncomplicated pyelonephritis (AUP) and intravenous (IV) MEC for suspected urosepsis (only in Denmark). Here, we wish to present an updated investigation on the clinical data behind these recommendations together with sparse but more current clinical data.

Methods

Prospective clinical trials evaluating MEC as monotherapy or in polytherapy with one other beta-lactam (mostly ampicillin [AMP]) for pyelonephritis or bacteremia were reviewed. Outcomes of primary interest were clinical and bacteriological success and relapse, respectively. Search databases used were PubMed, Cochrane Library, and Embase.

Results

Twelve clinical studies (1979-2015) were included in this integrated literature review. Clinical success was seen in 38/51 (75%) patients treated with MEC as monotherapy and in 152/164 (93%) patients treated with MEC and one other beta-lactam. Bacteriological success was seen in 35/47 (74%) and 117/167 (70%) patients treated with MEC alone and with one other beta-lactam, respectively. In complicated infections, bacteriological success was much lower. Clinical relapse rate was not well described. Several uropathogenic bacteremia cases were treated successfully with MEC alone (ie, 10/15 [67%] and 13/15 [87%] for clinical and bacteriological success, respectively) or with one other beta-lactam (ie, 57/65 [88%] and 53/63 [84%] for clinical and bacteriological success, respectively). However, data on bacteremia are very sparse. Adverse reactions were few and mild (73/406 [18%]) and primarily seen when AMP was co-administered (69/73 [95%]). No serious adverse reactions were reported.

Conclusion

IV MEC or oral P-MEC for 14 days may be suitable for the treatment of AUP and pediatric pyelonephritis. Randomized controlled trials using a single standardized dose of P-MEC compared to other current recommendations are warranted. Similarly, more evidence is required before MEC should be recommended for bacteremia or sepsis due to Enterobacteriaceae.