Unlike other available short-acting selective beta2-agonists, salmeterol possesses a longer duration of bronchodilation of at least 12 hours which allows for twice daily dosing. Salmeterol does not exhibit immediate pharmacologic activity due to its delayed onset of action. The onset of effective bronchodilation is approximately 10-20 minutes, with the time to maximum effect approaching one hour. This delayed onset has been attributed to slower receptor binding by salmeterol. Therefore, salmeterol administered either alone or in combination with fluticasone propionate is not effective in the treatment of acute asthmatic attacks but is reserved for use as preventive asthma therapy. Patients should never receive salmeterol as treatment for acute bronchospasm due to the delayed onset of action (10-20 minutes) attributed to this agent. Deaths have been reported when patients mistakenly used salmeterol to combat acute bronchospasm. Similarly, indacaterol, olodaterol, and vilanterol possess longer durations of bronchodilation allowing for once daily dosing and should also never be used to manage acute bronchospasm. Olodaterol is indicated for use as maintenance therapy in COPD while vilanterol is approved for the maintenance treatment of asthma and COPD.
For maintenance therapy, daily administration of LABAs alone or in combination with ICS is warranted in asthma and COPD. Formoterol combination products, olodaterol monotherapy and combination products, salmeterol monotherapy and combination products, and vilanterol combination products are metered-dose inhalers designed to deliver a set number of inhalations based on the canister size as well as the medication prescribed. Tables 5 and 6 summarize the number of inhalations available LABA and LABA combination products provide, respectively, and the days’ supply per inhaler or blister package based on the maximum dose allowed per day (see Tables 1 through 4). Excessive use may be identified based on refill frequency. Inappropriate supply of salmeterol metered-dose inhalers, salmeterol/fluticasone blister packages, formoterol blister packages, budesonide/formoterol metered-dose inhalers, or mometasone/formoterol metered-dose inhalers will be monitored by reviewing excessive refills.