A compliance study in general practice of patients switched from phenylbutazone and oxyphenbutazone to naproxen and other non-steroidal anti-inflammatory drugs.

Fifty-nine patients on long-term treatment with phenylbutazone or oxyphenbutazone for chronic rheumatic conditions were switched to treatment with naproxen and followed-up for 6 months in a compliance study. All patients were started on 500 mg naproxen twice daily but adjustment of the dosage was permitted. During the 6 months of the study only 3 patients returned to treatment with phenylbutazone. Of the remaining 56 patients, 45 were still taking naproxen after 6 months, 9 were changed to other non-steroidal, anti-inflammatory drugs and 2 were lost to follow-up. The study demonstrates that in routine general practice, phenylbutazone and oxyphenbutazone can be successfully replaced by less toxic drugs.