How To Use Primary Uses Indications Formoterol is a bronchodilator used for the treatment of asthma and Chronic Obstructive Pulmonary Diseases (COPD) such as Emphysema (breathing disorder affecting the air sacs in lungs) and bronchitis (inflammation of the respiratory passages). Side Effects The side-effects include headache, nausea, dizziness, anxiety, muscle cramps, joint pain, muscle pain, hypokalemia (low potassium in blood), throat and mouth irritation, sleep disorders, palpitations, hypersensitivity reactions, tremors, cardiac arrhythmias, and increase blood sugar levels. Contraindications