U.S. approval for commercial marketing of leeches for medicinal purposes

The Food and Drug Administration (FDA) has cleared the commercial marketing of leeches for medicinal purposes for the first time ever.

The medicinal leech has a long history of use in medicine, although today its use is mainly limited to limb reattachment procedures instead of the wide-ranging medical use of the past. Leeches were once so commonly used that doctors were popularly called leeches. In Old High German, lâhhi (etymon of leech) means "physician".

Leech saliva contains a number of compounds which assist in its feeding. An anaesthetic limits the sensations felt by the host (and thus reduce the chance of the host trying to detach the leech). A vasodilator causes the blood vessels near the leech to become dilated, and thus provide the leech with a better food supply.

Lastly, the leech saliva contains a complex protein called hirudin, which is a highly effective anticoagulant. The leech needs this to prevent blood clots (which would block its feeding) from forming in the wound created by its mouthparts. These properties are difficult to achieve using other medical techniques, and it is for this reason that leeches have come back into clinical practise in the last 25 years. The small amounts of hirundin present in leeches makes it unsuitable to be harvested for more general medical use, so hirudin (or related chemicals) have been synthesised using recombinant-DNA technology.

Bdellatomy is the practice of cutting the leech open slightly while it is sucking blood to let the blood in it out, so thinking that it is not full yet, the leech continues to bite instead of detach itself. This practise was first recorded in 1868 by Daily News.

Ricarimpex SAS, a French firm, is the first company to request and receive FDA clearance to market leeches as medical devices. The firm has been breeding leeches for 150 years. They are handled in a certified facility that tracks each lot.

In considering the firm’s application, FDA reviewed the published literature on the use of leeches in medicine and evaluated safety data provided by the firm. FDA also reviewed information on how the leeches are fed, their environment, and the personnel who handle them.

FDA determined that leeches are medical devices because they meet the definition of a medical device under the Food Drug and Cosmetic Act. Under the law, a medical device is an article intended to diagnose, cure, treat, prevent, or mitigate a disease or condition, or to affect a function or structure of the body, that does not achieve its primary effect through a chemical action, and is not metabolized.

Portions of this are licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Leech".