Salmeterol  and formoterol are long-acting ?2 agonists (LABAs) and chemical analogs of albuterol.Although both LABAs are usually used on a scheduled basis to control asthma, adults and adolescents with moderate persistent asthma can use the ICS/formoterol combination for relief of acute symptoms.Salmeterol and formoterol have a long duration of action, providing bronchodilation for at least
12 hours.