Iontophoresis is the process by which drugs, are introduced into a joint or small body part via electrical current. It is non-invasive, painless and it eliminates potential side effects and adverse reactions which can occur with medications delivered orally or by injection.
I have conducted an extensive literature search on the subject which I would be glad to share with you.
In 1979, Glass et al. conducted the most widely quoted research on iontophoresis. They applied it to multiple joints on a Rhesus monkey then excised the underlying tissue to determine depth of penetration. They found therapeutic concentrations of the drug at depths of up to 1.7 cm.. This is more than adequate for the superficial joints of the body such as the elbow, knee, ankle and shoulder.
Glass' conclusions have been confirmed many times. In 1982, Harris treated 50 patients with iontophoresis. Eighty-eight percent obtained excellent or good results with just three treatments. Also in 1982, Bertolucci performed a double blind study in which 53 patients, aged 18 to 65, received four iontophoresis treatments. Those under 44 years of age responded especially well though it should be noted that effectiveness decreased as the age of the patient increased.
Other studies have explored the long term use of this procedure with rheumatoid arthritis patients with good results, especially when applied to the knees.
Most interesting, however, is the amount of drug delivered through iontophoresis compared with oral meds and injections. Typical injection dosages were listed ranging from approximately 0.5mg for small joints to up to 4.0mg for large joints. Iontophoresis typically delivers 8 - 13ug/0.5 gram of exercised tissue or about 100 times less than an injection. However, oral dosages result in tissue concentrations of 7 - 200ng/0.5 gram of exercised tissue or 1,000 times less than the amount delivered by iontophoresis. So iontophoresis delivers less than a local injection, but provides much higher local concentrations than oral administration.
If you suffer from joint pain or inflammation, remember that iontophoresis can help. The staff at UCPT is skilled in this treatment and many other musculoskeletal physical therapy modalities and procedures.
Glass JM, Stephen RL, Jacobsen SC: The quality and distribution of radiolabelled dexamethasone delivered to tissues by iontophoresis. Int. J Dermatol 19:519-515, 1980
Berttolucci LE: Introduction of antiinflammatory drugs by iontophoresis: double blind study. JOSPT 4: 03-108, 1982
Harris, PR: Iontophoresis: clinical research in musculoskeletal inflammatory conditions. JOSPT 4:109-112, 1982
Iomed Information/Questions and Answer brochure, Trans Q1, 1990. Iomed of Salt Lake City.