Is oral or topical Diclofenac sodium better for muscle or joint pain?

Diclofenac sodium is a non-steroidal anti-inflammatory drug used to reduce inflammation and to reduce pain in conditions such as arthritis. Two routes of administration are available—oral as well as topical. The efficacy of oral non-steroidal anti-inflammatory drugs has been established for synovial (joint) and muscle tissue. However, there is little data available on the efficacy of topical NSAIDS. The results of a recent study published in the British Journal of Clinical Pharmacology (Miyatake et al, 2009) compared the concentration of diclofenac from topical and oral administration.

Dosages compared included a capsule containing 37.5mg of diclofenac sodium vs. 2 tapes containing 30mg of diclofenac sodium for topical application. Concentrations of diclofenac were measured in muscle, synovial membrane, and plasma 12 hours following administration.

Results: The diclofenac concentration was significantly higher in the muscle after topical application compared to oral administration (measured 12h after dosage). However, the concentrations in the synovial membrane was significantly lower after topic administration compared to oral administration. There were no significant differences in plasma diclofenac levels between either route of administration.

Conclusions: The results of this study suggest that topical administration of diclofenac sodium may actually be better for muscle pain. In contrast, these study results suggest that oral diclophanc sodium may be a better route of administration for people with joint pain or arthritis.

Side effects of Diclofenac sodium (among others)

1. Cardiac—potential increased risk of heart disease/myocardial infarction
2. Gastrointestinal—ulcers/bleeding.
3. Liver—damage/hepatitis
4. Kidney—adverse kidney effects
5. Other—bone marrow depression, affects blood clotting

Reference:
Miyatake S, Ichiyama H, Kondo E, Yasuda K. Randomized clinical comparisons of diclofenac concentration in the soft tissues and blood plasma between topical and oral applications. Br J Clin Pharmacol. 2009 Jan;67(1):125-9.