Budesonide/formoterol, sold under the brand name Symbicort among others, is a fixed-dose combination medication used in the management of asthma or chronic obstructive pulmonary disease (COPD). It contains budesonide, a steroid and formoterol, a long-acting β2-agonist (LABA). The product monograph does not support its use for sudden worsening or treatment of active bronchospasm. However, a 2020 review of the literature does support such use. It is used by breathing in the medication. Common (≥1/100 to <1/10) side effects include candidiasis, headache, tremor, palpitations, throat irritation, coughing, and dysphonia. Pneumonia is a common side effect in people with COPD, and other, less common side effects have been documented. There were concerns that the LABA component increases the risk of death in children with asthma, however these concerns were removed in 2017. Therefore, this combination is only recommended in those who are not controlled on an inhaled steroid alone. There is tentative evidence that typical doses of inhaled steroids and LABAs are safe in pregnancy. Both formoterol and budesonide are excreted in breast-milk. Budesonide/formoterol was approved for medical use in the United States in 2006. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. In 2020, it was the 61st most commonly prescribed medication in the United States, with more than 11million prescriptions. Medical uses Maintenance Budesonide/formoterol has shown efficacy to prevent asthma attacks. It is unclear if the efficacy of budesonide/formoterol differs from that of fluticasone and salmeterol in chronic asthma. Exacerbation The combination is approved in the United States only as a maintenance medication in asthma and chronic obstructive pulmonary disease (COPD). However, a 2020 review of the literature does support use as needed during acute worsening in those with mild disease, and as maintenance followed by extra doses during worsening. Use for both maintenance and as-needed treatment is also known as single maintenance and reliever therapy (SMART) and is a well-established treatment. It has been shown to, 1) reduce asthma exacerbations that require oral corticosteroids, 2) reduce hospital visits better than maintenance on inhaled corticosteroids alone at a higher dose, or 3) inhaled corticosteroid at the same or higher dose together with a long-acting bronchodilator (LABA), with a short-acting bronchodilator (SABA) as a reliever. Side effects Common (up to 1 in 10 people) Mild throat irritation Coughing Hoarseness Oral candidiasis (thrush. significantly less likely if the patient rinses their mouth