Continuous, low-level, topical heat wrap therapy as compared to acetaminophen for primary dysmenorrhea.

OBJECTIVE: To determine if pain relief provided by a wearable heat wrap (continuous, low-level, topical heat therapy) is superior to oral acetaminophen for primary dysmenorrhea.

STUDY DESIGN: A randomized, active-controlled, multisite, single-blind (investigator), parallel-design study compared an abdominal wrap to an oral medication (acetaminophen, 1000 mg) over I day. Pain relief (0-5) and abdominal muscle tightness/cramping (0-100) were recorded at 12 time points. At 24 and 48 hours, menstrual symptom-based quality of life was assessed.

RESULTS: Three hundred sixty-seven subjects entered the study, with 344 subjects evaluable. The heat wrap was superior to acetaminophen for pain relief over an 8-hour period (means of 2.48 and 2.17, p = 0.015) and at t hours 3, 4, 5 and 6 (p < or = 0.05). Tightness/cramping was less for the heat wrap versus acetaminophen over 8 hours (means of 40.4 and 44.5, p = 0.04) and at hours 4, 5 and 6 (p < or = 0.05). There was significantly decreased fatigue, fewer mood swings and less lower abdominal cramping (p < or = 0.05) with heat therapy.

CONCLUSION: Continuous, low-level, topical heat therapy was superior to acetaminophen for the treatment of dysmenorrhea.