Research Area: Infection Biological Activity: Moroxydine HCl is a synthetic antiviral drug chemically belonging to the series of the heterocyclic biguanidines. Structurally moroxydine is a heterocyclic biguanidine. [1] It possesses antiviral activity and is of value in the prevention and treatment of influenza. Although its mechanism of action is not fully known the effects seem to be due to an influence on the virus host-cell system. Oral medication has been shown to be effective against influenza, and small doses taken over a period of time have been shown to protect animals against influenza and other viral conditions. After preliminary trials with intramuscular injections the oral form of medication has been proven to be equally effective: pain usually disappears after two days, temperature reaches normal values and the lesion ceases to spread.