Assessment of efficacy of Oseltamivir-Azithromycin combination therapy in prevention of Influenza-A (H1N1)pdm09 infection complications and rapidity of symptoms relief

ABSTRACT

Objectives: This study aimed to assess the efficacy of oseltamivir-Azithromycin combination therapy for prevention of Influenza-A (H1N1)pdm09 infection associated complications and early relief of influenza symptoms.

Methods: In a retrospective observational cohort study, Influenza-A (H1N1)pdm09 infection hospitalized patients were identified and divided into two groups based on the initial therapy. Group-AV patients were initiated on Oseltamivir without any antibiotic in treatment regimen while Group-AV+AZ patients were initiated on Oseltamivir and Azithromycin combination therapy for at least 3-5 days. Patients were evaluated for different clinical outcomes.

Results: A total of 227 and 102 patients were identified for Group-AV and Group-AV+AZ respectively. Multivariate regression analysis showed that incidences of secondary bacterial infections were significantly less frequent (23.4% vs 10.4%; P-value = 0.019) in Group-AV+AZ patients. Group-AV+AZ patients were associated with shorter length of hospitalization (6.58 vs 5.09 days; P-value = <0.0001) and less frequent incidences of respiratory support (38.3% vs 17.6%; P-value = 0.016). Overall influenza symptom severity score was statistically significant less for Group-AV+AZ patients on Day-5 (10.68 ± 2.09; P-value = 0.001) of hospitalization.

Conclusion: Oseltamivir-Azithromycin combination therapy was found to be more efficacious as compared to oseltamivir alone in rapid recovery and prevention of Influenza associated complications especially in high risk patients.

KEYWORDS:

• Influenza A (H1)pdm09
• azithromycin
• oseltamivir
• antiviral combination
• symptom relief
• secondary bacterial infection
• influenza complications

Article highlights

• Effectiveness of influenza vaccine is inconsistent and varies from year to year specially in elderly population. Most of the previous researches mainly focused on the influenza-vaccinated patients. In current study, the majority of laboratory confirmed Influenza-A (H1N1)pdm09 patients were unvaccinated for influenza vaccine.

• Most commonly used antiviral drug i.e. Oseltamivir is most effective when initiated with 48 hours of symptoms onset. Most of the previous researches include patients who were initiated on Oseltamivir within 48 h of symptoms onset. All the patients of current study were those who were initiated on Oseltamivir after 48 hours of symptoms onset.

• Our study, to the best of our knowledge, is the study with largest number of laboratory confirmed Influenza-A (H1N1)pdm09 patients in which comparative efficacy of Antiviral drug (Oseltamivir) and Antiviral-Antibiotic (Oseltamivir–Azithromycin) combination has been assessed for the prevention of Influenza-A (H1)pdm09-associated complications and symptoms relief.

• Multivariate regression analysis has shown that patients who were initiated on Oseltamivir–Azithromycin combination therapy had suffered statistically significant secondary bacterial infections. Moreover, the length of hospitalization stay and need of respiratory support during hospitalization were also statistically significant less in patients with combination therapy.

• Overall symptom severity score was also found to be Oseltamivir–Azithromycin therapy was also found to be effective in early resolution of many influenza symptoms with statistically significant lower symptom severity score as compared to patients who were initiated on Oseltamivir alone.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

A reviewer on this manuscript has disclosed that they receive grant funding from Merck & Co.

Additional information

Funding

This paper was not funded.