An investigator-blind, parallel-group, multicentre study was undertaken to compare the efficacy and tolerability of once-daily, sustained-release (s-r)
ibuprofen and
diclofenac sodium in patients (mean age 59.8 years) suffering from painful
osteoarthritis affecting chiefly the knee and/or hip. Patients attending eight Swiss centres received either two s-r
tablets of
ibuprofen (daily dose 1600 mg;
n = 30) or a single s-r
diclofenac 100 mg
tablet (n = 31) each evening for 21 days. Clinical assessments were performed prior to initiating
therapy and after 7 and 21 days of treatment. Both treatments were efficacious, but statistically significant differences in favour of s-r
ibuprofen were observed for the principal measure of efficacy, the investigator's assessment of the overall change in clinical condition; by Day 21, 37% of
ibuprofen-treated patients vs 10% of
diclofenac-treated patients were 'much improved' (p = 0.04). Patients' assessments of the efficacy of their treatment also favoured s-r
ibuprofen at Day 7 for the relief of night
pain (p = 0.048), at Day 21 for alleviation of day
pain (p = 0.006) and for the ability to carry out normal activities (p = 0.01), and at both Days 7 and 21 for quality of sleep (p = 0.04 and 0.03, respectively). The patients' overall opinion of treatment was also significantly in favour of s-r
ibuprofen, which was rated 'good or excellent' by 80% (24/30), compared with only 38% of patients (11/29) receiving s-r
diclofenac sodium (p = 0.002). Two patients (6%) receiving s-r
diclofenac sodium ceased treatment owing to
dizziness and severe diarrhoea, respectively; there were no withdrawals in the
ibuprofen-treated group. Ten (32%) patients in the s-r
diclofenac group reported a total of 12 adverse events (mostly gastrointestinal in nature), compared with three (10%) patients in the s-r
ibuprofen group who reported only three events (
abdominal pain,
insomnia and
constipation). In conclusion, although both
NSAID treatments improved the clinical condition of patients with painful
osteoarthritis, statistically significant differences in favour of once-daily s-r
ibuprofen (1600 mg) were demonstrated in terms of efficacy, indicating a potential therapeutic advantage for this formulation.
Ibuprofen was also better tolerated than
diclofenac sodium (100 mg/day), the latter being associated with gastrointestinal side effects in a significant proportion of patients. Sustained-release
ibuprofen (
Brufen Retard) thus represents an important addition to the available therapeutic armamentarium of once-daily
NSAID formulations.