Drug under test: influenza--Relenza in daily practice. Experience during the influenza season 1999/2000

Therapy of experimental influenza virus infection with pyrrolidine dithiocarbamate

The search for new antiviral strategies to treat influenza A virus (IAV) infections is one major international health care activity. Hereby, the IAV-caused misuse of cellular nuclear factor kappa B (NF-κB) signaling pathways in infected cells represents one target for antiviral therapy. In the present study, pyrrolidine dithiocarbamate (PDTC), which is known as an antioxidant and as an inhibitor of IAV-induced NF-κB activation, was studied in vivo. After the antiviral activity of PDTC was confirmed in MDCK cells, mice-infected with the mouse-adapted strain of IAV A/PR/8/34 (H1N1)-were treated intraperitoneally simultaneously with PDTC (75, 150, 200 mg/kg body weight). The influence of PDTC administrations was evaluated on viral replication and inflammatory reactions in lung tissue up to 14 days postinfection (p. i.). This therapy increased survival up to 80% and reduced IAV-caused weight loss and viral replication in lung tissue in a dose-dependent manner. Protective effects were less pronounced, if the therapy started later on during an ongoing IAV infection. In addition, simultaneous PDTC treatment also limited IAV-caused infiltration of immune cells as well as local interferon-γ expression in lung tissue. These results imply that PDTC decreases IAV-caused disease in mice significantly. Therefore, the development of drugs like PDTC that interfere with NF-κB signaling may represent a modern focus of anti-IAV therapy.

Methodological considerations for future controlled influenza treatment trials in complementary and alternative medicine

BACKGROUND

The continuous threat of influenza pandemic, as well as the ongoing costs to human life and health care systems from yearly epidemics, create a continual need for progress in this area of public health. The diversity of available complementary and alternative medicine (CAM) treatment options are well known to the CAM profession, but poorly understood and accepted in mainstream medicine. This situation comes as no surprise given conventional medicine's reliance on repeated, large-scale randomized controlled trials of standardized design to support evidence-based clinical use of influenza antiviral drugs. The relatively low volume of well-conducted clinical trials on the treatment of influenza with CAM therapies compared to the high availability of conventional antiviral drug trials magnifies this problem.

OBJECTIVES

The aim of this article is to provide structured guidelines for future CAM influenza studies based on a thorough review of consistent and standard design elements present in the controlled-trial design of conventional antiviral influenza therapies.

RESULTS

A selection of high-quality, influenza antiviral controlled trials from the published literature is reviewed, and important design elements are extracted and summarized to show both the consistency and the flexibility within study design elements.

CONCLUSIONS

The standardized elements from influenza antiviral trials can be considered and mirrored in future CAM studies. In this way, CAM therapies might be looked at on similar grounds as conventional medicines in terms of potential usefulness and benefit in the treatment of influenza.