Strefen contains flurbiprofen. Flurbiprofen belongs to a group of medicines called non-steroidal anti-inflammatory drugs (NSAIDs) that have analgesic, antipyretic and anti-inflammatory properties. It is used for the relief of sore throat symptoms such as irritation, pain, difficulty swallowing and throat swelling in adults and adolescents aged 12 years and older. A doctor should be consulted if it worsens or if it does not improve after 3 days of treatment.