COMPLIANCE MONITORING OF NSAID DRUG THERAPY IN ANKYLOSING SPONDYLITIS, EXPERIENCES WITH AN ELECTRONIC MONITORING DEVICE

We conducted a randomized, controlled trial to compare once-daily20 mg piroxicam versus once-daily 20 mg tenoxicam in ankylosingspondylitis. We recorded patients' dosing histories with electronicmonitors for an average of 225 days (range 55–379) in34 recipients of piroxicam and 31 recipients of tenoxicam. Dosinghistories with the two agents were similar and are combined.Patients took 81% of prescribed doses; 78% once daily (as prescribed)and 3% as two or more daily doses. On 19% of all monitored days,there was no record of a dose being taken; 68% were single no-dosedays, the rest (32%) being 2 to > 10 consecutive no-dosedays. In 3% of monitored days, extra doses were evidently taken,88% as twice daily and 12% as three or more daily doses. Only22% of all patients (14/65) strictly complied with the regimen:one dose daily every day. The remainder alternated between no-dosedays and extra-dose days. We found no correlation between patientcompliance and improvement in reported pain or morning stiffness. KEY WORDS: Ankylosing spondylitis, Patient compliance, NSAIDs