Efficacy of topical diclofenac diethylamine gel in osteoarthritis of the knee.
OBJECTIVE
To assess the efficacy and safety of topical diclofenac diethylamine gel, 1.16%, 4 g applied qid for 3 weeks to relieve the symptoms of osteoarthritis (OA) of the knee.


METHODS
Patients with OA of the knee washed out their OA medications for at least 5 drug half-lives. Patients with adequately high baseline pain scores were randomized to apply either double-blind active or placebo gel for 3 weeks. Acetaminophen (up to 2 g/day) was supplied as rescue medication. In a diary, patients recorded compliance to dosing and use of rescue medication and assessed daily pain on movement, spontaneous pain, and pain relief. At weekly site visits, patients completed the Western Ontario and McMaster (WOMAC) Osteoarthritis Index Questionnaire, which includes assessment of pain, stiffness, and physical function, and assessed pain intensity "right now." At the final visit, a global assessment of treatment efficacy was completed.


RESULTS
Of 238 randomized patients, 237 were included in the intent to treat efficacy analysis. Treatments differed significantly for daily pain on movement at Day 5, and continued on most days through end of study. Peak differences were achieved in the second week. On the primary outcome, average pain on movement over Days 1-14, diclofenac gel was significantly superior to placebo gel. Scores for all 3 WOMAC indices for diclofenac gel treatment were significantly superior to placebo at Weeks 2 and 3. A significant difference was achieved on pain intensity "right now" at all 3 weeks. At the end of the study, patients rated diclofenac gel as significantly more effective in treating the pain of OA of the knee (p = 0.03) compared to placebo. There were no safety issues concerning adverse events or laboratory values.


CONCLUSIONS
Diclofenac gel was effective and safe for relief of symptoms of OA of the knee over 3 weeks of dosing.
Niethard
Fritz U
FU
Orthopaedic Clinic, Universitätsklinikum Aachen, Germany.
Gold
Morris S
MS
Solomon
Gail S
GS
Liu
Jiun-Min
JM
Unkauf
Markus
M
Albrecht
Helmut H
HH
Elkik
Francois
F
D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D004008:Diclofenac / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D005782:Gels; D006801:Humans; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D009068:Movement; D020370:Osteoarthritis, Knee / Q000188:drug therapy* / Q000503:physiopathology; D010146:Pain / Q000503:physiopathology; D010147:Pain Measurement; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
D000894:Anti-Inflammatory Agents, Non-Steroidal; D005782:Gels; D004008:Diclofenac