Long-Term Risk of Cardiovascular Death With Use of Clarithromycin and Roxithromycin: A Nationwide Cohort Study

Use of sensitivity analyses to assess uncontrolled confounding from unmeasured variables in observational, active comparator pharmacoepidemiologic studies: a systematic review

Understanding the potential for, and direction and magnitude of uncontrolled confounding is critical for generating informative real-world evidence. Many sensitivity analyses are available to assess robustness of study results to residual confounding, but it is unclear how researchers are using these methods. We conducted a systematic review of published active-comparator cohort studies of drugs or biologics to summarize use of sensitivity analyses aimed at assessing uncontrolled confounding from an unmeasured variable. We reviewed articles in 5 medical and 7 epidemiologic journals published between January 1, 2017, and June 30, 2022. We identified 158 active-comparator cohort studies: 76 from medical and 82 from epidemiologic journals. Residual, unmeasured, or uncontrolled confounding was noted as a potential concern in 93% of studies, but only 84 (53%) implemented at least 1 sensitivity analysis to assess uncontrolled confounding from an unmeasured variable. The most common analyses were E-values among medical journal articles (21%) and restriction on measured variables among epidemiologic journal articles (22%). Researchers must rigorously consider the role of residual confounding in their analyses and the best sensitivity analyses for assessing this potential bias. This article is part of a Special Collection on Pharmacoepidemiology.

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.

Introducing a Novel Combination Therapy with Macrolides for the Treatment of Chronic Rhinosinusitis: A Randomized Controlled Trial

BACKGROUND

Macrolides have shown beneficial effects in the treatment of chronic rhinosinusitis (CRS). This study aimed to compare the effect of azithromycin and clarithromycin in combination with conventional therapies for the treatment of CRS.

METHODS

This single-blind randomized controlled trial was conducted during 2018-2019 at the Otorhinolaryngology Clinic of Shahid Mohammadi Hospital, Bandar Abbas, Iran. Out of 102 selected patients, 90 were included in the analysis. Patients were selected through convenience sampling and randomly assigned to two equal groups. In addition to conventional therapies (nasal irrigation, betamethasone injection, oxymetazoline and fluticasone spray, guaifenesin syrup, and steam inhalation), the patients in the clarithromycin group received clarithromycin 500 mg tablets twice daily for four weeks. The other group received azithromycin 500 mg tablets daily for four weeks. Patients' symptoms were evaluated pre- and post-intervention, and the Lund-Mackay (LM) scoring system was used for the staging of CRS based on computed tomography scan findings. Data were analyzed using SPSS software, and P<0.05 was considered statistically significant.

RESULTS

Patients in both groups were comparable in terms of age and sex. Complete resolution of symptoms was significantly higher in the azithromycin group than the clarithromycin group (71.1% vs. 24.4%, P<0.001). Baseline LM scores did not differ significantly between the groups (P=0.120). However, post-intervention, LM scores reduced considerably in both groups, but the change was significantly higher in the azithromycin group (P<0.001).

CONCLUSION

In combination with conventional therapies for CRS in adults, a four-week course of treatment with azithromycin is more effective than clarithromycin.Trial Registration Number: IRCT20201209049661N1.

No dose-response relationship of clarithromycin utilization on cardiovascular outcomes in patients with stable coronary heart disease: Analysis of Taiwan's national health insurance claims data

BACKGROUND

Clarithromycin is widely used to treat various bacterial infections and has been reported to have potential cardiovascular risk. However, it is uncertain whether this association was dose dependent and confounded by indication bias in patients with stable coronary heart disease (CHD).

METHODS

This cohort study retrospectively analyzed a national health insurance claims data from Taiwan's 2005 Longitudinal Generation Tracking Database. We used a new-user design and 1:1 propensity score matching. A total of 9,631 eligible clarithromycin users and 9,631 non-users in 2004-2015 were subject to final analysis. All patients were followed-up after receiving clarithromycin or on the matched corresponding date until occurrence of cardiovascular morbidity in the presence of competing mortality, all-cause and cause-specific mortality, or through the end of 2015. The effect of cumulative dose, exposure duration, and indications of clarithromycin on cardiovascular outcomes were also addressed.

RESULTS

Clarithromycin use, compared with non-use, was associated with higher risk for all-cause [adjusted hazard ratios (aHR), 1.43; 95% confidence interval, 1.29-1.58], cardiovascular (1.35; 1.09-1.67), and non-cardiovascular (1.45; 1.29-1.63) mortality, but not for overall cardiovascular morbidity. Further analysis of individual cardiovascular morbidity demonstrated major risk for heart events (1.25; 1.04-1.51) in clarithromycin users than non-users. However, there was no relationship of cumulative dose, exposure duration, and indications of clarithromycin on cardiovascular outcomes. Analyses of the effects over time showed that clarithromycin increased cardiovascular morbidity (1.21; 1.01-1.45), especially heart events (1.39; 1.10-1.45), all-cause (1.57; 1.38-1.80), cardiovascular (1.58; 1.20-2.08), and non-cardiovascular (1.57; 1.35-1.83) mortality during the first 3 years. Thereafter, clarithromycin effect on all outcomes almost dissipated.

CONCLUSION

Clarithromycin use was associated with increased risk for short-term cardiovascular morbidity (especially, heart events) and mortality without a dose-response relationship in patients with stable CHD, which was not dose dependent and confounded by indications. Hence, patients with stable CHD while receiving clarithromycin should watch for these short-term potential risks.

Global review of macrolide antibiotics in the aquatic environment: Sources, occurrence, fate, ecotoxicity, and risk assessment

The extensive use of macrolide antibiotics (MCLs) has led to their frequent detection in aquatic environments, affecting water quality and ecological health. In this study, the sources, global distribution, environmental fate, ecotoxicity and global risk assessment of MCLs were analyzed based on recently published literature. The results revealed that there are eight main sources of MCLs in the water environment. These pollution sources resulted in MCL detection at average or median concentrations of up to 3847 ng/L, and the most polluted water bodies were the receiving waters of wastewater treatment plants (WWTPs) and densely inhabited areas. Considering the environmental fate, adsorption, indirect photodegradation, and bioremoval may be the main attenuation mechanisms in natural water environments. N-demethylation, O-demethylation, sugar and side chain loss from MCL molecules were the main pathways of MCLs photodegradation. Demethylation, phosphorylation, N-oxidation, lactone ring hydrolysis, and sugar loss were the main biodegradation pathways. The median effective concentration values of MCLs for microalgae, crustaceans, fish, and invertebrates were 0.21, 39.30, 106.42, and 28.00 mg/L, respectively. MCLs induced the generation of reactive oxygen species, that caused oxidative stress to biomolecules, and affected gene expression related to photosynthesis, energy metabolism, DNA replication, and repair. Moreover, over 50% of the reported water bodies represented a medium to high risk to microalgae. Further studies on the development of tertiary treatment technologies for antibiotic removal in WWTPs, the combined ecotoxicity of antibiotic mixtures at environmental concentration levels, and the development of accurate ecological risk assessment models should be encouraged.

A nationwide cohort study suggests clarithromycin-based therapy for Helicobacter pylori eradication is safe in patients with stable coronary heart disease and subsequent peptic ulcer disease

Background

Clarithromycin-based therapy is important for Helicobacter pylori eradication treatment. However, clarithromycin may increase cardiovascular risk. Hence, we investigated the association between clarithromycin use and outcomes in adults with stable coronary heart disease (CHD) and subsequent peptic ulcer disease (PUD).

Methods

This nationwide cohort study used a national health insurance database to screen 298,417 Taiwanese residents who were diagnosed with coronary heart disease from 2001 to 2015 for eligibility in the study and to evaluate select eligible patients with CHD–PUD from 2004 to 2015. Data were obtained from new users of clarithromycin (n = 4183) and nonusers of clarithromycin (n = 24,752) during follow-up. A total of 4070 eligible clarithromycin users and 4070 nonusers were subject to final analysis by 1:1 propensity score matching. Participants were followed up after receiving clarithromycin or at the corresponding date until the occurrence of cardiovascular morbidity in the presence of competing mortality, overall mortality and cardiovascular mortality, or through the end of 2015. The incidence rates and risks of overall mortality and cardiovascular outcomes were evaluated. The associations between clarithromycin and arrhythmia risk, as well as its dose and duration and overall mortality and cardiovascular outcomes were also addressed.

Results

Clarithromycin users were associated with adjusted hazard ratios of 1.08 (95% confidence interval, 0.93–1.24; 21.5 compared with 21.2 per 1000 patient-years) for overall mortality, 0.95 (0.57–1.59; 1.5 compared with 1.8 per 1000 patient-years) for cardiovascular mortality, and 0.94 (0.89–1.09; 19.6 compared with 20.2 per 1000 patient-years) for cardiovascular morbidity in the presence of competing mortality, as compared with nonusers. We found no relationship between dose and duration of clarithromycin and overall mortality and cardiovascular outcomes and no increased risk of arrhythmia during follow-up period. After inclusion of arrhythmia events to re-estimate the risks of all study outcomes, the results remained insignificant.

Conclusion

Concerning overall mortality, cardiovascular mortality, and cardiovascular morbidity, our results suggest clarithromycin-based therapy for Helicobacter pylori eradication may be safe in patients with stable CHD and subsequent PUD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02498-1.

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.

Genetic and pharmacological relationship between P-glycoprotein and increased cardiovascular risk associated with clarithromycin prescription: An epidemiological and genomic population-based cohort study in Scotland, UK

BACKGROUND

There are conflicting reports regarding the association of the macrolide antibiotic clarithromycin with cardiovascular (CV) events. A possible explanation may be that this risk is partly mediated through drug-drug interactions and only evident in at-risk populations. To the best of our knowledge, no studies have examined whether this association might be mediated via P-glycoprotein (P-gp), a major pathway for clarithromycin metabolism. The aim of this study was to examine CV risk following prescription of clarithromycin versus amoxicillin and in particular, the association with P-gp, a major pathway for clarithromycin metabolism.

METHODS AND FINDINGS

We conducted an observational cohort study of patients prescribed clarithromycin or amoxicillin in the community in Tayside, Scotland (population approximately 400,000) between 1 January 2004 and 31 December 2014 and a genomic observational cohort study evaluating genotyped patients from the Genetics of Diabetes Audit and Research Tayside Scotland (GoDARTS) study, a longitudinal cohort study of 18,306 individuals with and without type 2 diabetes recruited between 1 December 1988 and 31 December 2015. Two single-nucleotide polymorphisms associated with P-gp activity were evaluated (rs1045642 and rs1128503 -AA genotype associated with lowest P-gp activity). The primary outcome for both analyses was CV hospitalization following prescription of clarithromycin versus amoxicillin at 0-14 days, 15-30 days, and 30 days to 1 year. In the observational cohort study, we calculated hazard ratios (HRs) adjusted for likelihood of receiving clarithromycin using inverse proportion of treatment weighting as a covariate, whereas in the pharmacogenomic study, HRs were adjusted for age, sex, history of myocardial infarction, and history of chronic obstructive pulmonary disease. The observational cohort study included 48,026 individuals with 205,227 discrete antibiotic prescribing episodes (34,074 clarithromycin, mean age 73 years, 42% male; 171,153 amoxicillin, mean age 74 years, 45% male). Clarithromycin use was significantly associated with increased risk of CV hospitalization compared with amoxicillin at both 0-14 days (HR 1.31; 95% CI 1.17-1.46, p < 0.001) and 30 days to 1 year (HR 1.13; 95% CI 1.06-1.19, p < 0.001), with the association at 0-14 days modified by use of P-gp inhibitors or substrates (interaction p-value: 0.029). In the pharmacogenomic study (13,544 individuals with 44,618 discrete prescribing episodes [37,497 amoxicillin, mean age 63 years, 56% male; 7,121 clarithromycin, mean age 66 years, 47% male]), when prescribed clarithromycin, individuals with genetically determined lower P-gp activity had a significantly increased risk of CV hospitalization at 30 days to 1 year compared with heterozygotes or those homozygous for the non-P-gp-lowering allele (rs1045642 AA: HR 1.39, 95% CI 1.20-1.60, p < 0.001, GG/GA: HR 0.99, 95% CI 0.89-1.10, p = 0.85, interaction p-value < 0.001 and rs1128503 AA 1.41, 95% CI 1.18-1.70, p < 0.001, GG/GA: HR 1.04, 95% CI 0.95-1.14, p = 0.43, interaction p-value < 0.001). The main limitation of our study is its observational nature, meaning that we are unable to definitively determine causality.

CONCLUSIONS

In this study, we observed that the increased risk of CV events with clarithromycin compared with amoxicillin was associated with an interaction with P-glycoprotein.

The Role of Macrolides and Doxycycline in Chronic Rhinosinusitis

Antibiotic therapy has become an important adjunct in the management of recalcitrant chronic rhinosinusitis (CRS) because of some antibiotics' immunomodulatory properties even at subtherapeutic antimicrobial levels. Macrolide antibiotics, such as clarithromycin and azithromycin, decrease production of proinflammatory cytokines, impair neutrophil recruitment, inhibit bacterial biofilm formation, and improve mucus quality. Doxycycline, a tetracycline antibiotic, inhibits the activity of matrix metalloproteinases in CRS with nasal polyposis. This article reviews the clinical applications for macrolide and doxycycline use in CRS, considerations for dosing and duration of treatment, and important side effects and drug interactions associated with these medications.

Clarithromycin use and the risk of mortality and cardiovascular events: A systematic review and meta-analysis

Background

Although studies reported increased cardiovascular (CV) risks in patients treated with macrolides, the risks remain controversial among clarithromycin (CLR) users. We aimed to summarize the association between CLR use and the risks of mortality and CV events.

Methods

We searched PubMed, EMBASE, Web of Science, and the Cochrane Library for randomized controlled trials (RCTs) and observational studies with population exposed to CLR published until December 31^st, 2018. These studies reported either all-cause mortality (primary outcome) or CV adverse events (secondary outcomes) based on multivariate models. Effect measures were synthesized by study design and follow-up duration (long-term, ≥ 1 year; short-term, ≤ 3 months; and immediate, ≤ 2 weeks). This study has been registered on PROSPERO (ID: CRD42018089605).

Results

This meta-analysis included 13 studies (3 RCTs and 10 observational studies) and 8,351,815 subjects (1,124,672 cases and 7,227,143 controls). Overall, CLR use was not associated with increased long-term all-cause mortality (pooled rate ratio RR = 1.09, 95% CI = 0.91–1.32), either among patients with or without comorbidities of cardiovascular diseases. Comparing CLR users to placebo, there is no additional risks of cardiac mortality (pooled RR = 1.03, 95% CI = 0.53–2.01), acute myocardial infarction (pooled RR = 1.29, 95% CI = 0.98–1.68), and arrhythmia (pooled RR = 0.90, 95% CI = 0.62–1.32).

Conclusions

Our findings suggested no significant association between CLR use and subsequent long-term all-cause mortality, regardless having comorbidity of cardiovascular diseases or not. Further RCTs investigating the short-term CV risks of CLR use compared to alternative antibiotics are warranted, particularly in high-risk populations.

Diffuse maculopapular exanthema and a positive lymphocyte transformation test reaction in response to clarithromycin

Macrolides are one of the most widely used antibiotics, but the mechanisms underlying macrolide allergy have not been clearly elucidated. Diffuse maculopapular exanthema caused by clarithromycin is extremely rare, of which clinical images have not been reported. Here, we report a case of a 55-year-old Japanese female who was treated with oral clarithromycin and lysozyme hydrochloride due to odontogenic maxillary sinusitis. On the 15th day after starting both drugs, she suffered from diffuse maculopapular exanthema, which worsened despite the discontinuation of lysozyme hydrochloride and the introduction of treatment with oral and topical corticosteroids and oral levocetirizine. Clarithromycin was discontinued and an intravenous corticosteroid introduced on the 19th day. A lymphocyte transformation test was positive for clarithromycin but negative for lysozyme hydrochloride. Although adverse effects of clarithromycin are extremely rare, physicians should be aware of clarithromycin as a potential cause of a type IV allergic reaction.