Comtrex is used to treat symptoms of severe colds, including sinus pain and runny nose. It also helps relieve joint pain resulting from exposure to extreme cold. Comtrex treats headaches, muscle and joint pain. In addition, it is used to relieve sore throat and mouth as well as nasal congestion. Comtrex also helps reduce severe nasal secretions resulting from increased histamine and treats respiratory allergies. It is also used to reduce high temperatures.