Anti-inflammatory effects of macrolide antibiotics in the treatment of chronic rhinosinusitis

The Mechanism of Action and Clinical Efficacy of Low-Dose Long-Term Macrolide Therapy in Chronic Rhinosinusitis

Various chronic inflammatory airway diseases can be treated with low-dose, long-term (LDLT) macrolide therapy. LDLT macrolides can be one of the therapeutic options for chronic rhinosinusitis (CRS) due to their immunomodulatory and anti-inflammatory actions. Currently, various immunomodulatory mechanisms of the LDLT macrolide treatment have been reported, as well as their antimicrobial properties. Several mechanisms have already been identified in CRS, including reduced cytokines such as interleukin (IL)-8, IL-6, IL-1β, tumor necrosis factor-α, transforming growth factor-β, inhibition of neutrophil recruitment, decreased mucus secretion, and increased mucociliary transport. Although some evidence of effectiveness for CRS has been published, the efficacy of this therapy has been inconsistent across clinical studies. LDLT macrolides are generally believed to act on the non-type 2 inflammatory endotype of CRS. However, the effectiveness of LDLT macrolide treatment in CRS is still controversial. Here, we reviewed the immunological mechanisms related to CRS in LDLT macrolide therapy and the treatment effects according to the clinical situation of CRS.

Is there a role for antibiotics in the treatment of chronic rhinosinusitis?

Rhinosinusitis is one of the most common reasons for adult outpatient antibiotic prescriptions, though there is little clinical evidence to support this practice, especially for chronic rhinosinusitis. Despite considerable research, the etiology of chronic rhinosinusitis, including the pathogenic role of microbes, remains poorly understood. Rigorous studies of the efficacy of antibiotic treatment of chronic sinusitis are surprisingly few in number and the results are somewhat conflicting. This review article will review the rationales for and against the treatment of chronic rhinosinusitis with antibiotics, based on current evidence and understanding of pathophysiology, and will also summarize the current guidelines.

Sinus Fluid Penetration of Oral Clarithromycin and Azithromycin in Patients with Acute Rhinosinusitis

Background

The aim of this study was to investigate the extracellular concentration and the degree of sinus fluid penetration of newer macrolides, within the first 24–48 hours of treatment in patients with acute bacterial rhinosinusitis (ABRS), choosing clarithromycin and azithromycin as model antibiotics. An open, noninterventional pharmacokinetic study was performed at a tertiary teaching hospital.

Methods

In 36 outpatients with ABRS, sinus fluid aspirates and serum samples were collected 2, 4, 6, 8, and 12 hours or 2, 6, 12, and 24 hours after the administration of three doses of oral clarithromycin, 500 mg, twice daily or two doses of oral azithromycin, 500 mg, once daily, respectively. Drug concentrations were determined in both matrices by high-performance liquid chromatography with fluorometric detection, and the pH was estimated for all sinus fluid samples.

Results

The average clarithromycin sinus fluid concentration was found to be significantly higher than the corresponding azithromycin concentration (2.47 mg/L versus 0.65 mg/L), while the extent of the average sinus fluid penetration, expressed by the ratio of drug concentration in tissue versus serum, was similar for both drugs (115 and 120%, respectively).

Conclusion

In patients with ABRS, clarithromycin and azithromycin present adequate penetration into sinus fluid to eradicate erythromycin-sensitive strains of Streptococcus pneumoniae. Considering their comparative in vitro activity, the sinus fluid pH effect, and their sinus fluid penetration profile, we may conclude that among the erythromycin-resistant S. pneumoniae strains, clarithromycin might be advantageous over azithromycin in eradicating some of the low-level resistant strains.

Long-term postoperative azithromycin in patients with chronic rhinosinusitis: A randomized clinical trial

BACKGROUND

Chronic rhinosinusitis (CRS) is recognized as a common disease that imposes a big burden on the health system worldwide. There is ongoing evidence of the anti-inflammatory effect of long-term macrolide in the management of patients with CRS.

OBJECTIVE

The aim of this randomized clinical trial was to evaluate the efficacy of long-term consumption of low-dose azithromycin after functional endoscopic sinus surgery.

METHODS

Sixty-six patients who fulfilled the inclusion criteria were randomly divided into intervention and control groups. The subjects received the standard conventional treatment (fluticasone nasal spray plus normal saline solution irrigation) or the conventional treatment plus 250 mg of azithromycin on a daily basis for 3 months. Evaluation was made based on the 22-item Sino-Nasal Outcome Test (SNOT-22) immediately before surgery and 3 months after surgery.

RESULTS

The intervention group showed a statistically significant improvement in SNOT-22 scores after the treatment and a higher percentage change after 3 months of therapy compared with the control group. A significant correlation was found between the percentage change of SNOT-22 scores and smoking in the placebo group. Lund-Mackay scores, patient age, and the duration of symptoms had no significant correlation with the percentage change.

CONCLUSION

Treatment with long-term low-dose azithromycin in combination with the conventional therapy could statistically reduce the recurrence rate of CRS symptoms after functional endoscopic sinus surgery, but there was not sufficient evidence to support clinical significance of azithromycin at the investigated dose. Further larger scale trials, along with a longer follow-up period, is needed to evaluate the effectiveness of the therapy.

Relationship between chronic rhinosinusitis and lower airway diseases: An extensive review

Significant links between allergic rhinitis and asthma have been reported, and the united airway disease hypothesis is supported by numerous findings in epidemiologic, physiologic, pathologic, and immunologic studies. The impact of allergic rhinitis on asthma has been established. On the other hand, the relationship between chronic rhinosinusitis and lung diseases has been under investigation. Chronic rhinosinusitis is a common disease, and the high prevalence of chronic rhinosinusitis in some kinds of lung diseases has been reported. Recent studies suggest that the treatment of chronic rhinosinusitis has beneficial effects in the management of asthma. Here, we present an overview of the current research on the relationship between chronic rhinosinusitis and lower airway diseases including asthma, chronic obstructive pulmonary disease, cystic fibrosis, diffuse panbronchiolitis, primary ciliary dyskinesia, idiopathic bronchiectasis, and allergic bronchopulmonary aspergillosis.

High and low doses of clarithromycin treatment are associated with different clinical efficacies and immunomodulatory properties in chronic rhinosinusitis

BACKGROUND

Low-dose clarithromycin has been recommended for the treatment of chronic rhinosinusitis without nasal polyps. However, it is uncertain whether a high dose of clarithromycin is more effective than a low dose.

METHODS

Forty-three chronic rhinosinusitis patients were randomised to low-dose or high-dose clarithromycin groups, and clinical efficacy was evaluated. Pre- and post-treatment measures included: nasal symptom assessment, endoscopic inspection (Lund-Kennedy system), a quality of life questionnaire (the Sino-Nasal Outcome Test 20) and examination of cytokine levels (interleukin-5 and -8) in nasal secretions.

RESULTS

The high dose of clarithromycin was significantly better in terms of clinical efficacy than the low dose for the treatment of chronic rhinosinusitis (p < 0.025). Significant differences in nasal cytokine levels (interleukin-5 and -8) were also observed between the low-dose and high-dose groups after short-term clarithromycin treatment (p < 0.025).

CONCLUSION

Short-term, high-dose clarithromycin appears to be more effective for the treatment of chronic rhinosinusitis than low-dose clarithromycin.

Macrolide therapy for chronic rhinosinusitis: a meta-analysis

OBJECTIVE

The objective of this study was to systematically review patient-reported outcomes of long-term macrolide therapy, compared with any other treatment, for adults with chronic rhinosinusitis.

DATA SOURCES

EMBASE and PubMed databases were searched in October 2011.

REVIEW METHODS

A total of 1216 citations were screened initially by a single author, 23 full-text manuscripts were evaluated by 2 authors using structured data abstraction forms to assess for inclusion criteria and study quality, and 3 studies were included in the final review.

RESULTS

This review finds that 3 prospective clinical studies have evaluated the effect of macrolide therapy for chronic rhinosinusitis. Based on the limited data, there is limited scientific evidence to support the use of long-term macrolide therapy for chronic rhinosinusitis.

CONCLUSION

Further clinical research is needed to determine whether there may be a subgroup effect based on the underlying inflammatory disease process.

Efficacy of Chinese Herbal Medicine Compared with a Macrolide in the Treatment of Chronic Rhinosinusitis without Nasal Polyps

Background

This study was designed to examine the efficacy of Chinese herbal medicine (CHM) in the treatment of chronic rhinosinusitis (CRS) without nasal polyps.

Methods

Patients with CRS without nasal polyps were enrolled in the study. Before treatment, they were evaluated by the Taiwanese version of the 20-item Sino-Nasal Outcome Test (TWSNOT-20), nasal endoscopy, saccharin test, and bacterial culture. Then, they were randomized to take CHM (Tsang-Erh-San extract granules and Houttuynia extract powder) or erythromycin for 8 weeks. After treatment, they were evaluated again by the TWSNOT-20, nasal endoscopy, saccharin test, and bacterial culture.

Results

Fifty-three patients completed the study with 26 in the CHM group and 27 in the erythromycin group. In both the CHM and the erythromycin groups, TWSNOT-20 scores significantly decreased after treatment, but the decrease was not significantly different between the two groups. However, the saccharin transit times were shortened in more patients in the CHM group than in patients in the erythromycin group.

Conclusion

Our results showed CHM had an efficacy similar to that of macrolides in the treatment of CRS without nasal polyps. However, a placebo effect remained possible in both treatment groups.

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.

Negative predictive value of normal nasal endoscopy for sinus disease as a cause of isolated facial pain

OBJECTIVE

To determine the negative predictive value of normal nasal endoscopy in assessing paranasal sinus disease as the cause of isolated facial pain in the sinus regions.

SUBJECTS AND METHODS

The study group comprised 42 consecutive adult patients presenting with the isolated symptom of facial pain, and a negative nasal endoscopy. Patients underwent sinus computed tomography to determine whether radiographic findings indicated a sinugenic aetiology.

RESULTS

Patients comprised 27 women and 15 men, with a median age of 38 years. Twenty patients had unilateral pain, 33 per cent had sinus radiographic findings that might explain their facial pain, and 10 per cent had imaging demonstrating mucosal disease in one or more sinuses correlating with the location of the facial pain. Thirty-one per cent had anatomical radiographic findings that could potentially obstruct the osteomeatal unit.

CONCLUSION

Normal nasal endoscopy had a negative predictive value of 67 per cent in excluding a sinugenic cause of isolated facial pain, if radiographically determined anatomical factors and mucosal disease were both included as positive findings; this rose to more than 90 per cent if only those patients with mucosal sinus disease were considered as true positive patients.

Macrolide immunomodulation of chronic respiratory diseases

Important immunomodulatory properties of 14- and 15-membered macrolides may benefit patients with respiratory diseases associated with chronic inflammation. These properties include decreased neutrophil chemotaxis and infiltration into the respiratory epithelium, inhibition of transcription factors leading to decreased proinflammatory cytokine production, downregulation of adhesion molecule expression, inhibition of microbial virulence factors including biofilm formation, reduced generation of oxygen-free radicals, enhanced neutrophil apoptosis, and decreased mucus hypersecretion with improved mucociliary clearance. Chronic, low-dose macrolides have dramatically improved survival in patients with diffuse panbronchiolitis (DPB). Given the overlap in pathogenesis between DPB and other chronic respiratory diseases, macrolides are being investigated for cystic fibrosis, asthma, chronic bronchitis, chronic sinusitis, and chronic obstructive pulmonary disease. Preliminary data (largely from open-label trials) are promising, but conclusive results are needed.

Anti-inflammatory effects of macrolides: applications in chronic rhinosinusitis

The anti-inflammatory effects of macrolides are significant. The clinical impact on diffuse panbronchiolitis (DPB) has improved 10-year survival from 12% to more than 90% for these patients. The immunomodulatory activity of macrolides has been a source of mechanistic research as well as clinical research in non-DPB inflammatory airway disease. Suppression of neutrophilic inflammation of the airways has been demonstrated as the most robust immunomodulatory response from 14- and 15-membered ring macrolides. The inhibition of transcription factors, mainly nuclear factor-kB and activator protein 1, from alterations in intracellular cell signaling drives this mechanism. The suppression of interleukin-8 to a range of endogenous and exogenous challenges characterizes the alterations to cytokine production. The inflammatory mechanisms of chronic rhinosinusitis (CRS) have been a major non-DPB focus. Macrolides have been trialed in more than 14 prospective trials and are the focus of numerous research projects. Evidence for a strong clinical effect in CRS is mounting, but results may be tempered by researchers' inability to characterize the disease process. Eosinophilic dominated CRS is unlikely to respond, based on current research understanding and data from clinical trials. This article discusses the current concepts of macrolides and their application in the management of CRS.

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.

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.

Macrolide immunomodulatory effects and symptom resolution in acute exacerbation of chronic bronchitis and acute maxillary sinusitis: a focus on clarithromycin

Bacterial respiratory tract infections are common in the primary care setting and patients often seek the assistance of a healthcare professional in order to achieve resolution of their symptoms. Antibiotic agents that offer rapid symptom relief, in addition to excellent bacteriological and clinical cure, are highly desired. Macrolides have proven to be highly effective in treating acute bacterial exacerbations of chronic bronchitis and acute maxillary sinusitis. In addition, immunomodulatory effects that may contribute to symptom resolution have been reported. This article reviews current literature on symptom resolution in acute bacterial exacerbations of chronic bronchitis and acute maxillary sinusitis, with a focus on clarithromycin, and explores the potential mechanisms that may contribute to this action.