A bactericidal and virucidal pharmaceutical composition for use on epithelial tissues such as pulmonary, nasal and oral tissues, which comprises a non-steroidal anti-inflammatory drug (NSAID) in a concentration between 5 and 500 mM and a salt, being the NSAID preferably solubilized in a hypertonic saline solution applicable in therapies for viral infections of the Herpes simplex type. The composition can be used in therapies for herpes simplex viral infections, be used as a bactericidal mouthwash, or be vehiculated to the lung by using a nebuliser, for cystic fibrosis.