Selection of aspirin dosages for aspirin desensitization treatment in patients with aspirin-exacerbated respiratory disease

Background: Aspirin desensitization followed by daily aspirin therapy is effective add-on treatment for patients with aspirin-exacerbated respiratory disease. Prior studies used 650 mg of aspirin twice daily, but studies at lower dosages were inconclusive. Objective: We sought to determine the optimal daily dosage of aspirin treatment. Methods: We studied 137 patients who had undergone successful aspirin desensitization and randomized them into 2 groups, 650 mg twice daily versus 325 mg twice daily. After 1 month, patients either increased or decreased their dosage based on their symptom control and continued that dosage for the remainder of the year. Results: Patients taking either 650 mg twice daily or 325 mg twice daily showed significant improvements in number of sinus infections, sinus operations, and hospitalizations for asthma (all P <.0001). Anosmia, nasal/sinus symptoms, and asthma symptoms also improved in both groups (all P <.03). Systemic corticosteroid dosages decreased by 3- and 4-fold in the 325 mg twice daily and 650 mg twice daily groups, respectively. Of the 137 patients, 32 had adverse effects from or discontinued aspirin therapy: 14 (44%) of 32 from the group randomized to taking 650 mg twice daily and 18 (56%) of 32 from the group randomized to 325 mg twice daily. The most common adverse effect was dyspepsia. Conclusion: Both dosages were efficacious, and side effects occurred in both groups at similar frequencies. Some patients initially taking 325 mg twice daily required an increase to 650 mg twice daily for optimal symptom control. Clinical implications: We recommend that patients begin daily aspirin therapy with 650 mg twice daily and subsequently decrease to the lowest effective dosage (usually 325 mg twice daily).