Clarithromycin Extended-Release Tablet

Temporal dynamics of the soil resistome and microbiome irrigated with treated wastewater containing clarithromycin

Clarithromycin, a common antibiotic found in domestic wastewater, persists even after treatment and can transfer to soils when treated wastewater (TWW) is used for irrigation. This residual antibiotic may exert selection pressure, promoting the spread of antibiotic resistance. While Predicted No Effect Concentrations (PNECs) are used in liquid media to predict resistance risks, PNEC values for soils, especially for clarithromycin, are lacking. Thus, this study aimed to assess clarithromycin's fate and its concentration threshold affecting soil microbial communities and macrolide resistance genes. The study used a soil microcosm approach with TWW containing clarithromycin at concentrations of 0, 0.01, 0.1, 0.5, and 1 mg/kgdry soil over a three-month period. Results showed clarithromycin persisted with limited degradation, likely due to strong adsorption to soil particles. Two transformation products were identified: decladinose-CLA (abiotic degradation) and phosphate-CLA (bacterial phosphotransferase activity). Soil bacterial communities were more influenced by TWW than by clarithromycin itself, as its antimicrobial effect was reduced due to adsorption. While clarithromycin did not significantly affect the abundance of resistance genes like intl1, mphA, and ereA, concentrations above 0.01 mg/kg increased the ermB gene abundance during the first week. The mefA gene (macrolide efflux pump) showed a hormetic effect: low doses (<0.1 mg/kg) increased gene abundance, while higher doses (>0.5 mg/kg) inhibited gene transfer or the bacteria carrying it. This study performed under controlled conditions provided insights into antibiotic resistance dynamics in soils exposed to clarithromycin, highlighting key concentration thresholds influencing resistance spread in soils.

Short-course versus long-course therapy of the same antibiotic for community-acquired pneumonia in adolescent and adult outpatients

BACKGROUND

Community-acquired pneumonia (CAP) is a lung infection that can be acquired during day-to-day activities in the community (not while receiving care in a hospital). Community-acquired pneumonia poses a significant public health burden in terms of mortality, morbidity, and costs. Shorter antibiotic courses for CAP may limit treatment costs and adverse effects, but the optimal duration of antibiotic treatment is uncertain.

OBJECTIVES

To evaluate the efficacy and safety of short-course versus longer-course treatment with the same antibiotic at the same daily dosage for CAP in non-hospitalised adolescents and adults (outpatients). We planned to investigate non-inferiority of short-course versus longer-term course treatment for efficacy outcomes, and superiority of short-course treatment for safety outcomes.

SEARCH METHODS

We searched CENTRAL, which contains the Cochrane Acute Respiratory Infections Group Specialised Register, MEDLINE, Embase, five other databases, and three trials registers on 28 September 2017 together with conference proceedings, reference checking, and contact with experts and pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing short- and long-courses of the same antibiotic for CAP in adolescent and adult outpatients.

DATA COLLECTION AND ANALYSIS

We planned to use standard Cochrane methods.

MAIN RESULTS

Our searches identified 5260 records. We did not identify any RCTs that compared short- and longer-courses of the same antibiotic for the treatment of adolescents and adult outpatients with CAP.We excluded two RCTs that compared short courses (five compared to seven days) of the same antibiotic at the same daily dose because they evaluated antibiotics (gemifloxacin and telithromycin) not commonly used in practice for the treatment of CAP. In particular, gemifloxacin is no longer approved for the treatment of mild-to-moderate CAP due to its questionable risk-benefit balance, and reported adverse effects. Moreover, the safety profile of telithromycin is also cause for concern.We found one ongoing study that we will assess for inclusion in future updates of the review.

AUTHORS' CONCLUSIONS

We found no eligible RCTs that studied a short-course of antibiotic compared to a longer-course (with the same antibiotic at the same daily dosage) for CAP in adolescent and adult outpatients. The effects of antibiotic therapy duration for CAP in adolescent and adult outpatients remains unclear.

Generic versus non-generic formulation of extended-release clarithromycin in patients with community-acquired respiratory tract infections: a prospective, randomized, comparative, investigator-blind, multicentre study

BACKGROUND AND OBJECTIVE

There is a general concern about the use of multisource (generic) antibacterials in the clinical setting with registration based solely on bioequivalence data. In order to address this concern, two modified-release formulations of clarithromycin (i.e. the originator Klacid XL and the generic Klarithran MR) were compared in patients with acute community-acquired respiratory tract infections.

METHODS

Patients presenting with tonsillopharyngitis, sinusitis or pneumonia were randomized to receive either of the test drugs provided they clinically qualified for empirical clarithromycin treatment. The study endpoints were clinical and bacteriological cure rates, tolerability and safety. The study was designed to test for non-inferiority with regard to cure rates.

RESULTS

The main outcome of this study was that both agents had similar clinical (non-inferior) and bacteriological cure rates and demonstrated no difference in tolerability in patients. The study also demonstrated the clinical efficacy of clarithromycin when used as empirical treatment in patients with respiratory tract infections in community practice (i.e. 95% clinical cure rate).

CONCLUSION

The clarithromycin extended-release multisource product (Klarithran MR) does not differ significantly from the originator (Klacid XL) and the clinical cure rate of the generic formulation is non-inferior to that of the originator. The two formulations are tolerated similarly.

Macrolides beyond the conventional antimicrobials: a class of potent immunomodulators

The historical change in the natural course of diffuse panbronchiolitis (DPB), a fatal disorder of the airways, following the introduction of erythromycin in its treatment has focused attention of researchers on the anti-inflammatory properties of macrolides. Chronic inflammation of the airways accompanied by infiltration by neutrophils and overproduction of mucus and pro-inflammatory cytokines is observed in bronchial asthma, cystic fibrosis (CF), DPB, chronic obstructive pulmonary disease (COPD) and bronchiectasis. The airways of these patients are often colonised by mucoid Pseudomonas aeruginosa attached to epithelium by a biofilm. Bacteria intercommunicate for biofilm formation by a system of lactones known as quorum sensing. Macrolides inhibit mobility and quorum sensing of P. aeruginosa; they also decrease production of mucus by epithelial cells and biosynthesis of pro-inflammatory cytokines from monocytes and epithelial cells by inhibiting nuclear factor-kappaB. Large, randomised clinical trials for the management of these disorders with macrolides are not available, with the sole exception of four trials denoting benefit following long-term administration of azithromycin in patients with CF. That benefit is consistent with an increase in forced expiratory volume in 1s (FEV(1)) and a decrease in the rate of bacterial exacerbations. Studies with small numbers of patients with COPD revealed attenuation of the inflammatory reaction by macrolides. Experimental studies of Gram-negative sepsis have shown considerable attenuation of the systemic inflammatory response following intravenous administration of clarithromycin. Results of the effects of clarithromycin in patients with ventilator-associated pneumonia and sepsis in a large, randomised study of 200 patients are awaited.

Clinical pharmacokinetics and gastrointestinal tolerability of a novel extended-release microsphere formulation of azithromycin

BACKGROUND AND OBJECTIVE

A novel oral, extended-release, microsphere formulation of azithromycin (AZSR) was developed to improve the gastrointestinal tolerability profile while allowing administration of an entire treatment course of azithromycin in a single dose. Several phase I clinical pharmacology studies were conducted to (i) identify a well-tolerated single-dose formulation that met a predefined exposure target; and (ii) evaluate the effect of food and antacid on the absorption of this formulation. Of these, five pivotal studies are described here.

METHODS

The pharmacokinetic profile of AZSR was compared with that of the commercially available immediate-release azithromycin formulation (AZM) in an open-label, crossover, single-dose study (Study A), and their gastrointestinal tolerability profiles were compared in an observer-blind, parallel group, single-dose study (Study B). The effects of food (a high-fat meal and a standard meal) and antacid (a single 20 mL dose of Maalox Regular Strength, containing magnesium hydroxide, aluminium hydroxide and simethicone) on the absorption of azithromycin from AZSR were evaluated in three separate open-label, crossover, single-dose studies (Studies C, D and E). Healthy adult subjects were enrolled in all five studies, and all subjects were evaluable for tolerability. The dose used for all azithromycin formulations was 2.0 g. Serum azithromycin concentrations were determined using a validated high-performance liquid chromatography/electrochemical detection method, and pharmacokinetic parameters were analysed using noncompartmental methods.

RESULTS

377 subjects received a single 2.0 g dose of azithromycin as AZSR and/or AZM in the five studies. Compared with AZM, AZSR had a slower absorption rate (57% decrease in the mean peak concentration [C(max)] and an approximate 2.5-hour delay in the time to reach C(max) [t(max)]), with a mean relative bioavailability of 82.8%, which met the predefined exposure target (at least 80% bioavailability relative to AZM). Compared with AZM, AZSR was associated with significantly lower rates of nausea and vomiting. A high-fat meal increased the mean area under the serum concentration-time curve [AUC] from time zero to 72 hours post-dose (AUC(72 h)) by 23% and increased the C(max) of azithromycin by 115%. A standard meal increased the mean C(max) by 119% but had no clinically significant effect on the AUC(72 h). AZSR appeared to be better tolerated in the fasted state than in the fed state. The AUC(72 h) and C(max) of AZSR were not significantly affected by co-administration with a single dose of antacid.

CONCLUSIONS

The extended-release microsphere formulation of azithromycin, AZSR, allows administration of an entire therapeutic course of azithromycin as a well-tolerated single 2.0 g dose. This formulation should be administered on an empty stomach and can be co-administered with antacids.

Efficacité et tolérance de la clarithromycine, forme à libération modifiée en traitement court de cinq jours dans les exacerbations aiguës de bronchite chronique, comparativement à la télithromycine

BACKGROUND

The extended-release formulation of clarithromycin (CLA-ER) allows using this macrolide as a single daily dose. The purpose of this study was to evaluate the efficacy and safety of the CLA-ER formulation (500 mgx2) vs telithromycin (TELI) (400 mgx2) as a short course 5-day treatment, once a day, in patients with AECB.

METHOD

This randomized double-blind study was conducted in patients with AECB without severe airflow limitation (FEV1>35%), with sputum purulence (mandatory criterion), and with either increased sputum volume or increased dyspnea, or both (Anthonisen criteria I or II).

RESULTS

Three hundred sixty-two patients were assessed (62.6 years of age+/-12.9, men: 58.8%) positive culture on inclusion for 53.8%, with Haemophilus influenzae (N=57), Moraxella catarrhalis (N=42), and Streptococcus pneumoniae (N=41). In the per protocol population, the clinical success rate at day 8 was 97% (161/166) vs 97% (146/151), 97.5% CI=[-4.12 -4.71], the clinical cure rate at day 30 was 78% (129/166) versus 77% (116/151), P=0.85, and mean time without recurrence was 62 days versus 61 days (P=0.51), in CLA-ER and TELI groups, respectively. Fourteen patients in the CLA-ER group (8.2%) and 20 patients in the TELI group (12.4%) experienced at least one treatment-related adverse event (P=0.21), upon which gastrointestinal events were the most commonly reported treatment-related ones.

CONCLUSION

CLA-ER (1000 mg once a day) for 5 days is at least as effective as telithromycin in the treatment of AECB without severe airflow limitation and is well tolerated.

Once daily clarithromycin extended-release vs twice-daily amoxicillin/clavulanate in patients with acute bacterial sinusitis: a randomized, investigator-blinded study

OBJECTIVE

To compare the efficacy and tolerability of clarithromycin extended-release (ER) to amoxicillin/ clavulanate in patients diagnosed with acute bacterial sinusitis.

RESEARCH DESIGN AND METHODS

In a controlled, multicenter, investigator-blinded study, 437 ambulatory patients at least 12 years old with signs/symptoms and radiographic findings of acute sinusitis were randomized to receive clarithromycin ER 1000 mg once daily or amoxicillin/ clavulanate 875 mg/l25 mg twice daily for 14 days.

MAIN OUTCOME MEASURES

Clinical and bacteriological response rates were determined at a test-of-cure visit, which was conducted up to 10 days following the completion of treatment. Radiological response was assessed at a follow-up visit.

RESULTS

The clinical cure rate in clinically evaluable patients was 98% (184/188) in the clarithromycin ER group and 97% (179/185) in the amoxicillin/clavulanate group (95% CI for the difference in rates [-2.4%, 4.7%]). Clinical cure was sustained at the follow-up visit (96% for each treatment group). The pathogen eradication rates were 94% (61/65) in the clarithromycin ER group and 98% (61/62) in the amoxicillin/clavulanate group (95% CI for difference in rates [-12.0%, 2.9%]). The radiological success rate was 94% (172/183) in both the clarithromycin ER and amoxicillin/clavulanate groups (95% CI for difference in rates [-4.9%, 4.9%]). Symptomatic improvement or relief was observed as early as 2 days-5 days after the initiation of study drug, with a statistically significantly higher resolution rate of sinus pressure (p = 0.027) and improvement/resolution rate of nasal congestion (p = 0.035) during treatment with clarithromycin ER. The resolution/improvement rate at the test-of-cure visit for each treatment group was > or = 94% for the primary acute sinusitis signs/symptoms, with a statistically significantly higher resolution/improvement rate of purulent nasal discharge with clarithromycin ER (p = 0.010). Both study drugs had a positive and rapid impact on quality of life. Patients reported a high level of satisfaction and probability of using either study antibiotic again, and health care resource use was low, with slightly fewer sinusitis-related physician and outpatient visits required by patients in the clarithromycin ER group (p = 0.055). The treatment groups were comparable with respect to incidence of drug-related adverse events.

CONCLUSION

In this multinational population of patients with acute bacterial sinusitis, clarithromycin ER was comparable, and for selected measures superior, to amoxicillin/clavulanate based on clinical, bacteriological, and radiological responses as well as quality of life measures, satisfaction with antibiotic therapy, and health care resource utilization.