Serum and sputum antibiotic levels after ampicillin, amoxycillin and bacampicillin chronic bronchitis patients

Systematic review: the bioavailability of orally administered antibiotics during the initial phase of a systemic infection in non-ICU patients

Background

The systemic response to an infection might influence the pharmacokinetics of antibiotics. To evaluate the desired possibility of an earlier (< 24 h) IV-to-oral switch therapy in febrile non-ICU, hospitalized patients, a systematic review was performed to assess the effect of the initial phase of a systemic infection on the bioavailability of orally administered antibiotics in such patients.

Methods

An electronic search was conducted in MEDLINE and Embase up to July 2020. Studies were selected when outcome data were collected during the initial stage of a febrile disease. Outcome data were (maximum) serum concentrations, time of achieving maximum serum concentration, and the area-under-the-plasma-concentration-time curve or bioavailability of orally administered antibiotics. Risk of bias was assessed.

Results

We identified 9 studies on 6 antibiotics. Ciprofloxacin was the most frequently studied drug. Outcomes of the studies were heterogeneous and generally had a high risk of bias. Three small studies, two on ciprofloxacin and one on clarithromycin, compared the pharmacokinetics of febrile patients with those of clinically recovered patients and suggested that bioavailability was not altered in these patients. Other studies either compared the pharmacokinetics in febrile patients with reported pharmacokinetic values from earlier studies in healthy volunteers (n = 2), or provided no comparison at all and were non-conclusive (n = 4).

Conclusion

There is a clear knowledge gap regarding the bioavailability of orally administered antibiotics in non-ICU patients during the initial phase of a systemic infection. Well-designed studies on this topic are necessary to elucidate whether patients can benefit from the advantages of an earlier IV-to-oral switch.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05919-w.

A copper-dependent compound restores ampicillin sensitivity in multidrug-resistant Staphylococcus aureus

Multi-drug resistant Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), has become a worldwide, major health care problem. While initially restricted to clinical settings, drug resistant S. aureus is now one of the key causative agents of community-acquired infections. We have previously demonstrated that copper dependent inhibitors (CDIs), a class of antibiotics that are only active in the presence of copper ions, are effective bactericidal agents against MRSA. A second-generation CDI, APT-6K, exerted bactericidal activity at nanomolar concentrations. At sub-bactericidal concentrations, it effectively synergized with ampicillin to reverse drug resistance in multiple MRSA strains. APT-6K had a favorable therapeutic index when tested on eukaryotic cells (TI: > 30) and, unlike some previously reported CDIs, did not affect mitochondrial activity. These results further establish inhibitors that are activated by the binding of transition metal ions as a promising class of antibiotics, and for the first time, describe their ability to reverse existing drug resistance against clinically relevant antibiotics.

Amoxicillin concentrations in relation to beta-lactamase activity in sputum during exacerbations of chronic obstructive pulmonary disease

Background

Acute exacerbations of chronic obstructive pulmonary disease (COPD) are often treated with antibiotics. Theoretically, to be maximally effective, the antibiotic concentration at sites of infection should exceed the minimum inhibitory concentration at which 90% of the growth of potential pathogens is inhibited (MIC₉₀). A previous study showed that most hospitalized COPD patients had sputum amoxicillin concentrations <LMIC₉₀ when treated with amoxicillin/clavulanic acid. Those with adequate sputum concentrations had better clinical outcomes. Low amoxicillin concentrations can be caused by beta-lactamase activity in the lungs. This study investigated whether patients with sputum amoxicillin concentrations <MIC₉₀ had higher beta-lactamase activity in sputum than patients with a concentration ≥MIC₉₀.

Methods

In total, 23 patients hospitalized for acute exacerbations of COPD and treated with amoxicillin/clavulanic acid were included. Sputum and serum samples were collected at day 3 of treatment to determine beta-lactamase activity in sputum and amoxicillin concentrations in both sputum and serum.

Results

We found no difference in beta-lactamase activity between patients with sputum amoxicillin concentrations <MIC₉₀ and ≥MIC₉₀ (P=0.79). Multivariate logistic regression analysis showed no significant relationship between beta-lactamase activity and sputum amoxicillin concentrations <MIC₉₀ or ≥MIC₉₀ (odds ratio 0.53; 95% confidence interval 0.23–1.2; P=0.13). Amoxicillin concentrations were <MIC₉₀ in 78% of sputum samples and in 30% of serum samples.

Conclusion

In patients treated with amoxicillin/clavulanic acid for an acute exacerbation of COPD, sputum beta-lactamase activity did not differ between those with sputum amoxicillin concentrations <MIC₉₀ or ≥MIC₉₀. The finding that the majority of patients had sputum amoxicillin concentrations <MIC₉₀ suggests that current treatment with antibiotics for acute exacerbations of COPD should be optimized.

Evaluation of amoxicillin plasma and tissue levels in pediatric patients undergoing tonsillectomy

OBJECTIVE

Tonsillectomy is the most common surgery performed in the pediatric and young adult populations. Although recent guidelines based on meta-analysis suggest that perioperative chemoprophylaxis plays a role in reducing bacteraemia-related post-tonsillectomy complications, there is no evidence or agreement upon which specific antibiotic, dosage or administration route should be preferred. Since few previous studies have assessed the effectiveness of prophylaxis by direct measurement of antibiotic levels both in plasma and tissue, we designed an experimental study to quantitatively evaluate amoxicillin concentrations in children ready for tonsillectomy and compare these plasma and tissue levels with the Minimal Inhibitory Concentrations (MIC) of the bacteria more commonly involved in the upper airway infections.

METHODS

Thirty-three pediatric patients under 14 years of age (median 5.0, IQR 4-7, range 3-11; M:F 18:15) with recurrent tonsillitis were treated with 3 doses (established on patient's weight) of amoxicillin-clavulanic acid given orally the day before plus a further dose 2h before tonsillectomy. Amoxicillin concentrations on both homogenated tonsillar cores and plasma were measured by HPLC-UV. Bacterial epidemiology and susceptibility were derived respectively from survey data collected by Microbiology Unit and MIC according to the National Committee for Clinical Laboratory Standards (NCCLS).

RESULTS

Median plasma and tissue amoxicillin concentrations were respectively 4.7 microg/ml (IQR 2.1-8.0; min-max 0.4-14.3) and 1.1 microg/g (IQR 0.4-2.1; min-max 0.4-12.9), considerably below the selected target MIC of pathogens involved in the upper respiratory tract infections (S. aureus, H. influenzae, M. catarrhalis). 20 Children showed undetectable amoxicillin levels in one or both tonsils. Interestingly, 7 out of these patients (35%) had plasma concentrations higher than the target MIC (8 microg/ml). No patient displayed plasma concentrations under the limit of sensitivity of the method. Poor core-plasma and left-right core correlation was observed among patients, suggesting that fibrosis developed after recurrent tonsillitis may hamper antibiotic penetration.

CONCLUSIONS

Based upon direct measurement of antibiotic levels in plasma and tissue, this study suggests that a revision of the oral prophylaxis in children is required in order to reduce microbial charge in the operative field and accordingly improve the recovery after tonsillectomy.

Comparative activities of antibiotics against intracellular non-typeable Haemophilus influenzae

INTRODUCTION

Non-typeable Haemophilus influenzae (NTHi) is a major bacterial pathogen of community-acquired respiratory tract infection and is usually found extracellularly, although studies have revealed that NTHi may possess the ability to invade human epithelial cells where it is then protected against attack by the local immune system and partly against the effect of antibiotics. The aim of the present study was to assess the ability of ampicillin, azithromycin, telithromycin, ciprofloxacin and moxifloxacin, five antibiotics in common clinical use, to kill NTHi within bronchial epithelial cells.

METHODS

Confluent human bronchial epithelial cells were infected with NTHi 77, a particularly invasive clinical strain. Extracellular bacterial cells were killed with gentamicin and the intracellular bacteria were incubated with antibiotics at concentrations of 1 mg/l or 10 mg/l for 4 h or 8 h. Viable intracellular bacteria were counted after lysis of the epithelial cells.

RESULTS

With the exception of ampicillin, all the antibiotics caused significant reduction of intracellular bacteria at concentrations of 10 mg/l and exposure for 4 h or at 1 mg/l for 8 h. At 1 mg/l, moxifloxacin eliminated 94% of intracellular NTHi after 4 h and 98% after 8 h; ciprofloxacin, azithromycin and telithromycin only achieved killing indices below 75 after 4 h but 86-90% killing after 8 h. At 10 mg/l, moxifloxacin, ciprofloxacin, telithromycin and azithromycin were able to achieve 99.7%, 96.3%, 86.7% and 74.7% eradication of intracellular bacteria, respectively, after exposure for 4 h.

CONCLUSION

These results demonstrate the rapid antibacterial efficacy of moxifloxacin against intracellular NTHi in vitro. Moxifloxacin, which combines high extracellular and intracellular activities, could be an important tool in the treatment of recurrent respiratory tract infections.

Treatment of acute exacerbations of chronic bronchitis: state of the art

Effective treatment of acute bacterial exacerbations of chronic bronchitis (ABE) reduces the number of such exacerbations in such patients and may decrease or eliminate background symptoms and improve pulmonary function. The pathologic and physiologic abnormalities of the bronchial system in chronic bronchitis that predispose to bacterial infection probably include impaired mucociliary clearance, obstructed bronchioles, and bacterial infections of the bronchial epithelium. Exacerbations of bronchopulmonary symptoms are usually observed with ABE, although these symptoms are not unique to ABE. While culture and sensitivity testing is not usually required, microscopic examination of sputum is critical to determine the presence of bacterial infection. Bacteria in numbers significantly above the levels present when the patient's condition is stable and at least a doubling of the sputum neutrophil inflammatory level are essential criteria. Bacterial species observed with ABE include Haemophilus influenzae, Haemophilus parainfluenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Neisseria species, with a lesser incidence of Klebsiella and Pseudomonas species. One or more elements of background therapy for ABE should accompany antimicrobial therapy, for example, physiotherapy, bronchodilators, and so forth. Ampicillin is effective, safe, economical, and thus remains the drug of choice for ABE. Quinolones are an effective alternative when ampicillin cannot be tolerated or if organisms are resistant. Dosing is at the upper range of recommendations, and the chosen drug should be given for a 10-14-day regimen. Patients should be reevaluated if symptoms and physical findings do not return to baseline after 5-7 days.

Ciprofloxacin in the treatment of acute exacerbations of chronic bronchitis

Eighty hospital patients with acute purulent exacerbations of chronic bronchitis associated with Haemophilus influenzae, Streptococcus pneumoniae, Branhamella catarrhalis or Pseudomonas aeruginosa were treated with ciprofloxacin. The patients were divided into four groups of 20 patients each and administered either 500 mg, 750 mg (two different batches of tablets) or 1000 mg twice daily for ten days. Most of the patients with Haemophilus influenzae and Branhamella catarrhalis infections were treated successfully but the results in patients with Streptococcus pneumoniae and Pseudomonas aeruginosa infections were less satisfactory. Although the ciprofloxacin MICs for the latter organisms were relatively low, mean serum and sputum concentrations measured on the first day of treatment did not exceed 2-3 mg/l and 1-2.3 mg/l respectively. The overall clinical results for all dosage regimes were only fair, mainly due to failure to eradicate Streptococcus pneumoniae and Pseudomonas aeruginosa. Adverse effects (nausea, stomach pain or hallucinations) were seen in eight patients, causing treatment to be discontinued in five. It is concluded that ciprofloxacin is only of limited use in the treatment of respiratory tract infections unless Streptococcus pneumoniae is absent.

The quinolones in chronic bronchitis

Results are presented from 186 hospitalized patients treated for acute purulent exacerbations of chronic bronchitis with orally administered ciprofloxacin (80 patients), enoxacin (26 patients), ofloxacin (30 patients) or pefloxacin (50 patients). In general, good clinical results were observed in 50-70% of the patients treated, most failures being due to relapses or reinfections with Streptococcus pneumoniae or Pseudomonas aeruginosa. Studies on blood and sputum concentration suggested that gastro-intestinal absorption was not always satisfactory. Unwanted drug effects were noted with all agents studied, generally presenting as stomach pain, nausea, hallucinations, or dizziness. Most adverse drug reactions were seen with enoxacin, often but not always during concomitant treatment with theophylline.

A comparative study of amoxycillin and pivampicillin in persistent Haemophilus influenzae infection of the lower respiratory tract in children with chronic lung disease

A double-blind cross-over study was undertaken to compare the efficacy of amoxycillin and pivampicillin on Haemophilus influenzae infection of the lower respiratory tract in children. 20 patients with cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD) due to other causes were included in the study. All patients had a history of regularly harbouring H. influenzae in sputum and repeated treatment failures with pivampicillin. 18 completed two 14-day courses in random order with equimolar doses of pivampicillin (80 mg/kg/day) and amoxycillin (62 mg/kg/day). Both drugs were well tolerated with no serious side effects, but pivampicillin was associated with more pronounced nausea. In steady state the mean serum concentrations of antibiotics 2 and 4 h after medication were 9.7 and 3.7 micrograms/ml for pivampicillin and 19.1 and 7.9 micrograms/ml for amoxycillin (p less than 0.01). Eradication of H. influenzae and clinical improvement was seen in one-third of the courses with both drugs. Betalactamase producing ampicillin-resistant strains emerged during 58% of the amoxycillin courses, but only in 16% of the pivampicillin courses (p less than 0.001). The high number of treatment failures and the development of resistant strains indicate that betalactamase inhibitors may possibly improve the efficacy of these drugs, especially of amoxycillin, in these patients.

[New oral quinolone compounds in chronic bronchitis]

Clinical, microbiological and pharmacokinetic results are presented from studies in 186 patients treated with the new quinolone antimicrobial agents enoxacin, pefloxacin, ciprofloxacin or ofloxacin. Almost all had been admitted to hospital for acute purulent exacerbations of chronic bronchitis, associated mainly with Haemophilus influenzae, Streptococcus pneumoniae, Branhamella catarrhalis or Pseudomonas aeruginosa. The H. influenzae and B. catarrhalis strains were generally very sensitive to the quinolones and sputum concentrations of 1.3 to 4.5 mg/l exceeded the MICs (geometric mean values 0.07 to 0.44 mg/l) by a factor of more than 10. In contrast, P. aeruginosa was slightly less sensitive (geometric mean MICs 0.4 to 4.4 mg/l) and S. pneumoniae much less so (with geometric mean MICs between 0.84 and 6.7 mg/l) and a number of treatment failures were noted with these organisms. Various unwanted drug effects (mostly upper gastro-intestinal) were seen, particularly with enoxacin. The best clinical results were observed with ofloxacin, even with once daily dosage, but the results with the other quinolones could only be described as moderate.

The management of elderly patients with acute lower respiratory tract infections: a comparison of pivampicillin and amoxycillin

In a randomized trial, the efficacy of pivampicillin (500 mg or 1 g twice daily) was compared with that of amoxycillin (250 mg or 500 mg 3-times daily) in 43 elderly hospitalized patients with bronchopneumonia (32 patients) or an acute exacerbation of chronic bronchitis (11 patients). Overall, 13 (57%) out of the 23 patients taking pivampicillin were cured, and the remaining 10 subjects were improved. In the amoxycillin group, there were 9 (45%) cures, 9 improved and 2 failures of treatment. One patient in each treatment group had mild side-effects. Forty (93%) out of the 43 patients in the study expressed a preference for an antibiotic that was given twice daily as opposed to one where 3 doses were taken each day.

Bacampicillin hydrochloride: chemistry, pharmacology, and clinical use

Bacampicillin hydrochloride is an orally administered ester of ampicillin that is rapidly and completely hydrolyzed in vivo to ampicillin. The most notable advantage of bacampicillin over ampicillin is its superior bioavailability--bacampicillin achieves significantly higher blood and tissue levels and attains peak blood levels more rapidly than equimolar doses of oral ampicillin. In addition, the percentage of an oral dose of ampicillin that is absorbed decreases sharply as the size of the dose is increased from 500 mg to 2 g; this phenomenon is not observed with equipotent doses of bacampicillin. The enhanced absorption of bacampicillin in the upper gastrointestinal tract results in a frequency of diarrhea that appears to be markedly lower than that of ampicillin and similar to that observed with amoxicillin. Apart from the sizable differences between bacampicillin and ampicillin with regard to oral absorption, the pharmacokinetic and pharmacologic profiles of these two agents are essentially identical. Twice daily dosing (pulse dosing) with bacampicillin has been shown in numerous clinical trials to be of equivalent efficacy to ampicillin given four times daily or amoxicillin given three times daily in the treatment of infections of the upper respiratory tract, lower respiratory tract, skin and soft tissues, and urinary tract. The unanswered question is whether twice daily ampicillin or amoxicillin would yield similar results.

A review of the therapeutic efficacy of aerosolized and endotracheally instilled antibiotics

Achievement of sufficient concentrations of aerosolized antibiotic at the site of infection is limited by technical problems in antibiotic delivery and by drug inactivation. Antibiotic delivery by aerosolization is generally associated with minimal systemic absorption, whereas systemic absorption may be significant after endotracheal instillation. Methodologic problems make correlations between clinical response and sputum antibiotic concentrations difficult. Studies suggest that aerosolized antibiotics are of little value in the treatment of chronic bronchopulmonary infections. Endotracheal instillation appears to be associated with favorable clinical responses, possibly due to enhanced antibiotic delivery to the site of infection. Prophylactic aerosolized antibiotics are effective in altering sputum flora; reduction in mortality from acquired pneumonia has not been demonstrated. The development of resistant organisms may occur as a result of prophylactic treatment.

Bactericidal activity of erythromycin in the respiratory system

In vivo and in vitro studies were carried out to assess tha levels in bronchial mucus of ampicillin, amoxycillin, bacampicillin, cefotaxime and erythromycin, and to compare their minimum bactericidal concentrations and killing rate against hospital strains of Staphylococcus aureus, Streptococcus pyogenes and Haemophilus influenzae. Both the percentage ratios of serum/mucus concentration peaks and of serum/mucus area under the concentration time curve values were higher for erythromycin than for the other antibiotics. Determination of the minimum bactericidal concentrations showed that the bacterial strains were sensitive to small quantities of erythromycin, and the time necessary to sterilize inocula varied from 4 to 16 hours.

The aminopenicillins: development and comparative properties

In this review we have compared and contrasted the antibacterial and pharmacological properties of the aminopenicillins currently available. It is apparent that there is little hard evidence (except in the case of thphoid fever) that either amoxycillin or the pro-drug esters of ampicillin are significantly more effective than ampicillin itself, despite their better absorption and higher serum levels. However, amoxycillin and the ampicillin pro-drug esters do cause fewer bowel side-effects than ampicillin, which may justify their use despite the extra cost involved. The problem of susceptibility to penicillinases is unlikely to be solved by modification of the aminopenicillin molecule. A more likely solution is administration of these substances with beta-lactamase inhibitors such as clavulanic acid. Trials with such combinations are already under way.

Studies on aminopenicillin developments. Proceedings of a symposium. Concluding remarks

This symposium has focused on the bacteriological, pharmacokinetic, therapeutic, and adverse effects of the aminopenicillins. The compounds which are currently being assessed are primarily amoxycillin, ampicillin, bacampicillin, pivampicillin, and talampicillin. The three last mentioned are prodrugs which upon gastrointestinal absorption are rapidly split to yield circulating ampicillin. Pharmacokinetics and side-effects are reasons why one may narrow the selection of most suitable compounds within this group down to three. Ampicillin and amoxycillin are primary choices for parenteral dosage, and amoxycillin and bacampicillin the most suitable for oral therapy.