Influenza ("Bird Flu"), inflammation and anti-inflammatory/analgesic drugs

The spectre of an influenza pandemic is being widely mooted. Most of the strategies explored to date for controlling or treating the condition have centred on controlling the spread of the infection, the use of vaccines or anti-viral agents. There has been relatively little discussion about treating the lung and systemic inflammatory reactions that occur during influenza infection. In this review a range of therapeutic agents are proposed to treat the inflammatory reactions, principally in the lung as well as the systemic cytokine-mediated immuno-inflammatory reactions that may be a major cause of the morbidity and mortality associated with influenza infections. Among these are pentoxifylline, the statins, the macrolide antibiotics (e.g. azithromycin, clarithromycin, erythromycin), resveratrol (a component of wine and fruits with inhibitory effects on influenza virus replication) and nutraceuticals (including those that contain flavonoids, the marine oils eicosapentanoic and docosanoic acids or the green-lipped mussel extract, Liprinol which may by virtue of the inhibitory effects on the production or actions of pro-inflammatory cytokines, be useful for their anti-inflammatory actions. The efficacy, mode of actions and side effects of non-steroidal anti-inflammatory drugs (NSAIDs) are considered. There are a number of issues relating to their use in treating the inflammatory reactions in the respiratory tract. Among these are the development of gastro-intestinal ulcers and bleeding and hepato-renal reactions in patients that may because of severe systemic inflammation be prone to the development of these adverse reactions. There are also theoretical issues concerning the impact of COX-1 mediating reduction in prostaglandin and increased cytokine production that might have some negative consequences for respiratory inflammation.In conclusion, further consideration should be given to exploring the actions of these anti-inflammatory agents to control the respiratory inflammatory in influenza infections which can have serious consequences for the outcome of the infection.