Adverse effects of budesonide formoterol mainly involve the cardiovascular system, respiratory system, and oral and endocrine systems. Budesonide formoterol is an inhaler with anti-inflammatory and antiasthmatic effects, and is mainly used clinically for the treatment of asthma and chronic obstructive pulmonary disease. Budesonide formoterol can cause palpitations, headache, and tachycardia, and other side effects of the cardiovascular system. The budesonide in budesonide formoterol is a cortisol hormone that can affect fetal development and the growth of children with long-term use. Therefore, if you are a child, pregnant or breastfeeding woman, you should consult a respiratory or obstetrician-gynecologist when using budesonide formoterol. Budesonide formoterol can cause irritation of the larynx, causing cough, hoarseness, and bronchospasm. In patients with chronic obstructive pulmonary disease, the use of budesonide formoterol may also cause lung infections. Budesonide formoterol may also cause Candida infections in the oral pharynx, nausea and abnormal taste. To avoid these side effects, it is recommended to rinse your mouth with water after each use of budesonide formoterol and always spit out the mouthwash and never swallow the mouthwash.