Osteoarthritis pain relieved by leeches
Leech therapy appears to improve the symptoms of osteoarthritis and could offer patients an alternative approach to pain relief, a new study reveals.
Researchers from the University of Duisburg-Essen in Germany decided
to test their hypothesis that substances found in leech saliva might
relieve osteoarthritic pain through their effects on inflammation. They
assigned 51 patients with osteoarthritis of the knee to either leech
therapy or treatment with diclofenac gel.
Patients in the leech therapy group had one treatment session during
which four to six leeches were applied to the affected knee and left
until they detached themselves. Patients in the diclofenac group were
instructed to apply the gel to the affected knee at least twice a day
for 28 days. Patients’ pain, stiffness and function were assessed
by the researchers after three, seven, 28 and 91 days using standard
questionnaires.
The researchers found that patients assigned to leech therapy reported
less pain at day seven than patients who used diclofenac gel. They also
reported less stiffness, better function and fewer total arthritic symptoms
throughout the 91 days of the study, although both groups reported similar
amounts of pain at 28 and 91 days.
The researchers suggest that the therapeutic effect of leeches in osteoarthritis
may be due to salivary secretion of analgesic agents, such as inhibitors
of kallikrein, as well as anti-inflammatory agents, including proteinase
inhibitors. “Through the concomitant activity of a further leech
saliva component, hyaluronidase, these substances might reach deeper
tissue zones and possibly the joint space,” they say.
The researchers emphasise the preliminary nature of the trial (Annals of Internal Medicine 2003;139:724).
The author of an accompanying editorial suggests that future studies
should consider the mechanism of action by which leech therapy might
exert an analgesic effect. “The more exciting aspect of this work
is the potential for the discovery of a novel analgesic agent that could
be safely administered without the need for a leech bite,” he adds
(ibid, p781). |
