Antiviral treatment and prophylaxis of influenza in primary care: German recommendations.

Antiviral drugs are a valuable supplementation to vaccines for the control and prevention of influenza. In Germany, for treating influenza amantadine, oseltamivir and zanamivir are approved. Amantadine and oseltamivir are also licensed for prophylactic use. On behalf of the Paul-Ehrlich-Society of Germany and the German Association for the Control of Virus Diseases, as two independent scientific societies, the first consensus Conference on the Antiviral Treatment and Prophylaxis of Influenza was held in June 2002. Based on the available data of clinical studies an expert group developed the following recommendations for the appropriate clinical use of the antiviral drugs: (1) since oseltamivir (orally administered) and zanamivir (administered by inhalation) have apparently similar clinical efficacy both drugs can be used alternatively for treatment. (2) Amantadine is not an alternative to the neuraminidase (NA) inhibitors because it is not effective against influenza B viruses, it frequently selects resistant virus mutants and it can cause adverse events. (3) When influenza is prevalent in the community patients with the clinical diagnosis of influenza should be treated with neuraminidase inhibitors if the symptoms are lasting not longer than 48 h. (4) Immunocompetent patients with a non-febrile illness and patients with a symptom history of more than 2 days should not be treated with antiviral drugs. (5) Although there are no data from clinical trials immunocompromised patients should also be treated when influenza has been diagnosed. (6) The prophylactic use of antiviral drugs can be recommended for persons with close contact to acutely ill persons and no recent vaccination against influenza. (7) The use of anti-influenza drugs have to be considered for prophylaxis in pandemics. A precondition for the adequate use of anti-influenza drugs in the primary medical care is the timely information on the local influenza situation delivered by surveillance systems.