Treatment of chronic rhinosinusitis with low-dose, long-term macrolide antibiotics: an evolving paradigm

Safety review of current systemic treatments for severe chronic rhinosinusitis with nasal polyps and future directions

Introduction: Chronic rhinosinusitis is a common condition characterized by inflammation of the nasal and sinus linings, rhinorrhea, nasal blockage, facial pain, and loss of sense of smell for longer than 12 weeks. CRS can occur with or without nasal polyps.Areas covered: First-line treatment in chronic rhinosinusitis with nasal polyps is long-term intranasal corticosteroids, which have few adverse events associated with their use, as second-generation intranasal corticosteroids having a bioavailability of <0.5%. Systemic corticosteroids are used when intranasal steroids fail to achieve symptom control. However, the repeated use of oral corticosteroids is associated with numerous adverse events and the benefit from a course of oral corticosteroids is lost within three to six months.Expert opinion: Antibiotics are commonly prescribed in nasal polyposis although there is also very little evidence for their use outside of acute infection. Macrolide antibiotics are also associated with a transient increase in the risk of arrhythmias. Biologics offer a steroid-sparing alternative to the treatment of severe nasal polyposis. They have shown to be relatively well tolerated in studies to date; however, studies suggest that there is no disease modifying effect and that any benefit is lost within weeks of finishing treatment.

Systemic and topical antibiotics for chronic rhinosinusitis

BACKGROUND

This review is one of six looking at the primary medical management options for patients with chronic rhinosinusitis.Chronic rhinosinusitis is common and is characterised by inflammation of the lining of the nose and paranasal sinuses leading to nasal blockage, nasal discharge, facial pressure/pain and loss of sense of smell. The condition can occur with or without nasal polyps. Systemic and topical antibiotics are used with the aim of eliminating infection in the short term (and some to reduce inflammation in the long term), in order to normalise nasal mucus and improve symptoms.

OBJECTIVES

To assess the effects of systemic and topical antibiotics in people with chronic rhinosinusitis.

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Trials Register; CENTRAL (2015, Issue 8); MEDLINE; EMBASE; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 29 September 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) with a follow-up period of at least three months comparing systemic or topical antibiotic treatment to (a) placebo or (b) no treatment or (c) other pharmacological interventions.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Our primary outcomes were disease-specific health-related quality of life (HRQL), patient-reported disease severity and the commonest adverse event - gastrointestinal disturbance. Secondary outcomes included general HRQL, endoscopic nasal polyp score, computerised tomography (CT) scan score and the adverse events of suspected allergic reaction (rash or skin irritation) and anaphylaxis or other very serious reactions. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics.

MAIN RESULTS

We included five RCTs (293 participants), all of which compared systemic antibiotics with placebo or another pharmacological intervention.The varying study characteristics made comparison difficult. Four studies recruited only adults and one only children. Three used macrolide, one tetracycline and one a cephalosporin-type antibiotic. Three recruited only patients with chronic rhinosinusitis without nasal polyps, one recruited patients with chronic rhinosinusitis with nasal polyps and one had a mixed population. Three followed up patients for 10 to 12 weeks after treatment had finished. Systemic antibiotics versus placebo Three studies compared antibiotics with placebo (176 participants).One study (64 participants, without polyps) reported disease-specific HRQL using the SNOT-20 (0 to 5, 0 = best quality of life). At the end of treatment (three months) the SNOT-20 score was lower in the group receiving macrolide antibiotics than the placebo group (mean difference (MD) -0.54 points, 95% confidence interval (CI) -0.98 to -0.10), corresponding to a moderate effect size favouring antibiotics (moderate quality evidence). Three months after treatment, it is uncertain if there was a difference between groups.One study (33 participants, with polyps) provided information on gastrointestinal disturbances and suspected allergic reaction (rash or skin irritation) after a short course of tetracycline antibiotic compared with placebo. We are very uncertain if antibiotics were associated with an increase in gastrointestinal disturbances (risk ratio (RR) 1.36, 95% CI 0.22 to 8.50) or skin irritation (RR 6.67, 95% CI 0.34 to 128.86) (very low quality evidence). Systemic antibiotics plus saline irrigation and intranasal corticosteroids versus placebo plus saline irrigation and intranasal corticosteroids One study (60 participants, some with and some without polyps) compared a three-month course of macrolide antibiotic with placebo; all participants also used saline irrigation and 70% used intranasal corticosteroids. Disease-specific HRQL was reported using SNOT-22 (0 to 110, 0 = best quality of life). Data were difficult to interpret (highly skewed and baseline imbalances) and it is unclear if there was an important difference at any time point (low quality evidence). To assess patient-reported disease severity participants rated the effect of treatment on a five-point scale (-2 for "desperately worse" to 2 for "cured") at the end of treatment (three months). For improvement in symptoms there was no difference between the antibiotics and placebo groups; the RR was 1.50 (95% CI 0.81 to 2.79; very low quality evidence), although there were also slightly more people who felt worse after treatment in the antibiotics group. There was no demonstrable difference in the rate of gastrointestinal disturbances between the groups (RR 1.07, 95% CI 0.16 to 7.10). General HRQL was measured using the SF-36. The authors stated that there was no difference between groups at the end of treatment (12 weeks) or two weeks later. Systemic antibiotics versus intranasal corticosteroids One study (43 participants, without polyps) compared a three-month course of macrolide antibiotic with intranasal corticosteroids. Patient-reported disease severity was assessed using a composite symptom score (0 to 40; 0 = no symptoms). It is very uncertain if there was a difference as patient-reported disease severity was similar between groups (MD -0.32, 95% CI -2.11 to 1.47; low quality evidence). Systemic antibiotics versus oral corticosteroids One study (28 participants, with polyps) compared a short course of tetracycline antibiotic (unclear duration, ˜20 days) with a 20-day course of oral corticosteroids. We were unable to extract data on any of the primary efficacy outcomes. It is uncertain if there was a difference ingastrointestinal disturbances (RR 1.00, 95% CI 0.16 to 6.14) or skin irritation (RR 2.00, 95% CI 0.20 to 19.62) as the results for these outcomes were similar between groups (very low quality evidence).

AUTHORS' CONCLUSIONS

We found very little evidence that systemic antibiotics are effective in patients with chronic rhinosinusitis. We did find moderate quality evidence of a modest improvement in disease-specific quality of life in adults with chronic rhinosinusitis without polyps receiving three months of a macrolide antibiotic. The size of improvement was moderate (0.5 points on a five-point scale) and only seen at the end of the three-month treatment; by three months later no difference was found.Despite a general understanding that antibiotics can be associated with adverse effects, including gastrointestinal disturbances, the results in this review were very uncertain because the studies were small and few events were reported.No RCTs of topical antibiotics met the inclusion criteria.More research in this area, particularly evaluating longer-term outcomes and adverse effects, is required.

WITHDRAWN: Systemic antibiotics for chronic rhinosinusitis without nasal polyps in adults

Review withdrawn from Issue 4, 2016. Review replaced by 'Systemic and topical antibiotics for chronic rhinosinusitis' (Head 2016).

The editorial group responsible for this previously published document have withdrawn it from publication.

Pathogen- and host-directed anti-inflammatory activities of macrolide antibiotics

Macrolide antibiotics possess several, beneficial, secondary properties which complement their primary antimicrobial activity. In addition to high levels of tissue penetration, which may counteract seemingly macrolide-resistant bacterial pathogens, these agents also possess anti-inflammatory properties, unrelated to their primary antimicrobial activity. Macrolides target cells of both the innate and adaptive immune systems, as well as structural cells, and are beneficial in controlling harmful inflammatory responses during acute and chronic bacterial infection. These secondary anti-inflammatory activities of macrolides appear to be particularly effective in attenuating neutrophil-mediated inflammation. This, in turn, may contribute to the usefulness of these agents in the treatment of acute and chronic inflammatory disorders of both microbial and nonmicrobial origin, predominantly of the airways. This paper is focused on the various mechanisms of macrolide-mediated anti-inflammatory activity which target both microbial pathogens and the cells of the innate and adaptive immune systems, with emphasis on their clinical relevance.

Systemic antibiotics for chronic rhinosinusitis without nasal polyps in adults

BACKGROUND

Chronic rhinosinusitis (CRS) is a common health problem which significantly affects quality of life. A wide range of medical and surgical therapies have been used to treat CRS. Both systemic and topical antibiotics are used with the aim of eliminating infection and inflammation, altering bacterial biofilm formation, reversing ostial occlusion and improving symptoms. Various groups of systemic antibiotics have been studied; clinical cure rates reported are inconsistent and range from 50% to 95%.

OBJECTIVES

To determine the effectiveness and adverse reactions associated with systemic antibiotic therapy for CRS in adults.

SEARCH STRATEGY

We searched the Cochrane ENT Group Trials Register; CENTRAL (2010, Issue 2); PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; ISRCTN and additional sources for published and unpublished trials. The date of the most recent search was 10 June 2010.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing systemic antibiotics with placebo for chronic rhinosinusitis in adults.

DATA COLLECTION AND ANALYSIS

Two authors extracted data independently, compared results and resolved disagreements by discussion. We assessed treatment effect by calculating the risk ratio (RR) and 95% confidence intervals (CI) of cure at a specific time point for each trial. We used mean difference (MD) and 95% CI for continuous variables (severity scores, duration of symptoms, etc.).

MAIN RESULTS

We included one study involving 64 patients. We assessed the overall risk of bias in this study as high. The study reported that roxithromycin could reduce the mean response score of patients by 0.73 points on a 1 to 6-point scale (95% CI 0.32 to 1.14, P = 0.0005) compared to those on placebo at three months after the start of treatment. This study also used sinonasal outcome test-20 (SNOT-20) comparing between pre and post-treatment at six, 12 and 24 weeks. The mean change in SNOT-20 from baseline at 24 weeks in the roxithromycin group was not significantly more than in the placebo group, at 0.27 points (95% CI -0.24 to 0.78, P = 0.30) on a 0 to 5-point scale.

AUTHORS' CONCLUSIONS

There is limited evidence from one small study to support the use of systemic antibiotics for the curative treatment of chronic rhinosinusitis in adults. Further good quality trials, with large sample sizes, are needed to evaluate the use of antibiotics in chronic rhinosinusitis.

Mechanisms of action and clinical application of macrolides as immunomodulatory medications

Macrolides have diverse biological activities and an ability to modulate inflammation and immunity in eukaryotes without affecting homeostatic immunity. These properties have led to their long-term use in treating neutrophil-dominated inflammation in diffuse panbronchiolitis, bronchiectasis, rhinosinusitis, and cystic fibrosis. These immunomodulatory activities appear to be polymodal, but evidence suggests that many of these effects are due to inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and nuclear factor kappa B (NF-kappaB) activation. Macrolides accumulate within cells, suggesting that they may associate with receptors or carriers responsible for the regulation of cell cycle and immunity. A concern is that long-term use of macrolides increases the emergence of antimicrobial resistance. Nonantimicrobial macrolides are now in development as potential immunomodulatory therapies.

Management of chronic rhinosinusitis in CF

Routine CF management often does not include upper airway (UAW) assessment although CFTR defects equally affect the sinonasal mucosa. Up to 50% of CF patients have chronic rhinosinusitis (CRS) and/or nasal polyps, and almost 100% reveal UAW abnormalities on CT scan. CRS impairs quality of life. UAW dysfunction in filtering, humidifying, and warming inspired air affects lower airways and the UAW is a potential site of first colonization and a reservoir for opportunistic bacteria. Therefore, UAW pathology substantially affects overall health in CF. Standard treatments are scarce and mostly lack evidence. Nasal douche can remove mucus and crusts. Recently, delivery of dornase alfa using a vibrating aerosol has shown potential as treatment for CF-related CRS. Surgery is indicated when conservative approaches fail but postoperative relapse is frequent. In summary, upper airway involvement in CF is undertreated and requires prospective investigation and an interdisciplinary consensus on diagnosis and therapy.

Clarithromycin suppresses airway hyperresponsiveness and inflammation in mouse models of asthma

Macrolide antibiotics, a class of potent antimicrobials, also possess immunomodulatory/anti-inflammatory properties. These properties are considered fundamental for the efficacy of macrolide antibiotics in the treatment of diffuse panbronchiolitis and cystic fibrosis. In patients with asthma, macrolide antibiotics have been reported to reduce airway hyperresponsiveness and improve pulmonary function. However, their beneficial actions in asthmatics possibly could be attributed to antimicrobial activity against atypical pathogens (e.g. Chlamydia pneumoniae), corticosteroid-sparing effect (inhibition of exogenous corticosteroid metabolism), and/or their anti-inflammatory/immunomodulatory effects. In order to investigate whether efficacy of macrolide antibiotics in asthma results from their immunomodulatory/anti-inflammatory activity, the influence of clarithromycin pretreatment (2 h before challenge) was examined on ovalbumin-induced airway hyperresponsiveness and airway inflammation in the mouse. Clarithromycin treatment (200 mg/kg intraperitoneally) decreased IL-4, IL-5, IL-13, CXCL2 and CCL2 concentrations in bronchoalveolar lavage fluid and markedly reduced inflammatory cell accumulation in bronchoalveolar lavage fluid and into the lungs, as revealed by histopathological examination. Furthermore, clarithromycin-induced reduction in inflammation was accompanied by normalization of airway hyperresponsiveness. In summary, in ovalbumin-induced mouse models, clarithromycin efficiently inhibited two important pathological characteristics of asthma, airway hyperresponsiveness and inflammation. These data suggest that the efficacy of clarithromycin, as well as of other macrolide antibiotics, in asthmatic patients could be attributed to their anti-inflammatory/immunomodulatory properties, and not only to their antimicrobial activity or exogenous corticosteroid-sparing effects.

Nasal and sinus disease in cystic fibrosis

Paranasal and sinus disease is present in almost every patient with cystic fibrosis. However, symptoms are rarely reported. Some aspects including polyposis and microbial flora change with patient age. Endoscopy and computerised tomography have broadened our understanding of how this disease affects the sinuses, including an increased recognition of polyposis than previously thought and identification of several disease specific entities such as abnormalities of the lateral nasal wall and uncinate process. Few randomised, controlled trials evaluating medical or surgical treatments of CF sinus disease exist. Sinus surgery may provide some benefit, though there are no established selection criteria for appropriate candidates. A link between sinus disease and lower respiratory tract function may contribute to general health and survival following lung transplantation. Complications of sinonasal disease in CF are rare and include mucoceles and periorbital abscesses.

Anti-inflammatory treatment of chronic rhinosinusitis: a shifting paradigm

Treatment of chronic rhinosinusitis still represents an unmet medical need. Presently, the US Food and Drug Administration has not approved any drugs for the treatment of this common condition. Various inflammatory processes are involved in the pathogenesis of chronic rhinosinusitis. Treatment of infection and surgical intervention to correct anatomic abnormalities often are inadequate in management when singly employed. Anti-inflammatory therapy such as topical cortico-steroids and more recently long-term, low-dose macrolide therapy has been integrated into the treatment algorithm for chronic rhinosinusitis. Better classification and point-of-care identification of inflammatory features may improve choice of anti-inflammatory therapy and thus outcome.

Macrolide antibiotics as immunomodulatory medications: proposed mechanisms of action

Macrolide antibiotics administered in sub-antimicrobial doses improve pulmonary function and decrease exacerbation frequency for persons with diffuse panbronchiolitis or cystic fibrosis. Data also suggest a beneficial effect of macrolide antibiotics in the treatment of steroid dependent asthma. Many potential immunomodulatory effects of macrolide antibiotics have been reported including the ability to down-regulate prolonged inflammation, decreasing airway mucus secretion, inhibiting bacterial biofilm, decreasing the production of reactive oxygen species, inhibiting neutrophil activation and mobilization, accelerating neutrophil apoptosis, and blocking the activation of nuclear transcription factors. Macrolides initially decrease, then increase, and have finally a sustained suppression of cytokine secretions from normal human bronchial epithelial cells through inhibition and activation of extracellular signal-regulated kinases (ERK) and then reversibly retard cell proliferation probably through ERK. Consistent with this, macrolide antibiotics possibly reduce mucin production as well as neutrophil migration by interfering with ERK signal transduction.

The inhibitory effects of macrolide antibiotics on bone remodeling in chronic rhinosinusitis

OBJECTIVE

To investigate the effect of nasal mucosal inflammation on bone remodeling and the inhibitory effect of macrolide antibiotics on bone remodeling through the inhibition of receptor activator of nuclear factor-kappaB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF).

STUDY DESIGN AND SETTING

Human nasal fibroblasts were primary-cultured from nasal polyp. After interleukin (IL)-1beta stimulation of fibroblasts with or without macrolide pretreatment, real-time polymerase chain reaction for RANKL messenger RNA (mRNA) and enzyme-linked immunosorbent assay for M-CSF were performed at various intervals. Peripheral blood mononuclear cells (PBMCs) were cultured for 10 days with M-CSF only, M-CSF plus RANKL, or macrolide antibiotic plus M-CSF and RANKL.

RESULTS

IL-1beta stimulation of nasal polyp fibroblasts induced expression of RANKL mRNA and secretion of M-CSF. Macrolide antibiotics reduced RANKL mRNA and M-CSF expression by nasal polyp fibroblasts in a dose-dependent manner, and inhibited osteoclastogenesis from PBMCs.

CONCLUSION

Nasal fibroblasts stimulated with IL-1beta may take on the role of osteoblasts in osteoclastogenesis, which may be inhibited by macrolide antibiotics.

Anti-inflammatory treatment of chronic rhinosinusitis: A shifting paradigm

Treatment of chronic rhinosinusitis still represents an unmet medical need. Presently, the US Food and Drug Administration has not approved any drugs for the treatment of this common condition. Various inflammatory processes are involved in the pathogenesis of chronic rhinosinusitis. Treatment of infection and surgical intervention for correction of anatomical abnormalities often are inadequate in management when singly employed. Anti-inflammatory therapy such as topical cortico-steroids and more recently long-term, low-dose macrolide therapy have been integrated into the treatment algorithm for chronic rhinosinusitis. Better classification and point-of-care identification of inflammatory features may improve choice of anti-inflammatory therapy and thus outcome.