Symbicort (budesonide / formoterol) is a combination inhaler containing a steroid (budesonide) and a long-acting beta-agonist (formoterol). Both medications work together to treat asthma and chronic obstructive pulmonary disease (COPD). The typical dose for Symbicort (budesonide / formoterol) is 2 inhalations by mouth twice a day, about 12 hours apart. Common side effects include symptoms of common cold, such as stuffy nose and cough. It's available in two different strengths, both with generic versions.