BackgroundShoulder pain related to the rotator cuff (RC) is one of the most common and bothersome musculoskeletal complaints. Pharmacologic treatment most often includes acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen. However, data allowing comparison of the efficacy of these two drugs are very limited. We compared the therapeutic outcomes of acetaminophen and ibuprofen in the management of RC-related pain.MethodsThis was an open-label, two-center, active-control, prospective randomized clinical trial. Participants were assigned randomly to acetaminophen or ibuprofen treatment groups. The acetaminophen dose was 500 mg every 6–8 h, and it was 400–800 mg every 6–8 h for ibuprofen. The impact of the treatment was measured by Shoulder Pain and Disability Index (SPADI), Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) and World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaires at baseline and after 6 weeks of therapy.ResultsThirty-three patients completed the study; 20 treated with ibuprofen and 13 with acetaminophen. Patients in both groups were comparable at baseline with regard to SPADI, Quick-DASH, and WHOQOL-BREF scores. After 6 weeks of treatment, patients receiving ibuprofen, but not acetaminophen, reported an improvement in pain severity and functional activity (as measured by SPADI and Quick-DASH). Patients taking acetaminophen, but not ibuprofen, reported improvement in the physical and environmental domains of WHOQOL-BREF scores.ConclusionsIbuprofen and acetaminophen provide benefits to patients suffering from RC-related pain. However, the type of improvement perceived by patients differed between these two medications.