Hyaluronidase (AKA: Wydase) can be used to "melt" or accelerate the enzymatic degradation of injected hyaluronic acid based fillers, like Restylane, Juvederm, Prevelle - silk, etc.  This is quite useful in correcting areas of previous over-injection.  The volume of hyaluronidase injected depends on the amount of melting desired.  Contrary to some assertions, over-injection of hyaluronidase will not damage the skin or its native structural components.  Too much hyaluronidase will however melt more filler than desirable.  As such, we recommend a slow, minimal dose approach to correcting such over-correction problems.  With 10 units of injected hylauronidase most minor deformities can be corrected in several days time. If there is a need for more hyaluronidase, we repeat in 7 to 14 days.  Again we dont want to melt too much of the injected material.  Despite allergic reaction in our published study, we have not has any problems using Vitrase branded hyaluronidase. We have injected hyaluronidase in the lips, under the eyes, nasolabial lines, and in the nose for the purpose of reducing previously injected HA filler.  All should be aware that these are all strictly "off-label" applications and the patient should be thoroughly educated on this fact and potential risks. Below is a brief outline of Vitrase, the FDA-approved hyaluronidase we use:

The Food and Drug Administration approved Vitrase (hyaluronidase for injection). Vitrase is an injectable drug approved as an adjunct to (in combination with) other injected drugs to increase their absorption and dispersion. Hyaluronidase has been used most commonly in combination with local anesthetics in the setting of ophthalmic (eye) surgery. Hyaluronidase increases tissue permeability and promotes the spread or dispersion of other drugs, for example, speeding the onset of action for an anesthetic. Vitrase is also approved for use as an adjunct to rehydrating agents, and for use with certain imaging agents. Vitrase is a sheep sourced (ovine) form of hyaluronidase.

Hyaluronidase has not been available in the U.S. for the past 3 years due to the previous manufacturer's business decision to no longer market the product. The efficacy of hyaluronidase was evaluated and confirmed under the Drug Efficacy Study Implementation process (DESI) in l970. DESI was a retrospective evaluation of the effectiveness of the drug products that FDA had permitted on the market as safe through the new drug review process between 1938 and 1962.

This approval was based on product specific manufacturing information together with published literature on hyaluronidase, and other available public information. The manufacturer, Ista Pharmaceuticals, Inc., also conducted a clinical safety study. Clinical studies have shown hyaluronidase to be effective and that most adverse reactions which may occur with the use of hyaluronidase are allergic reactions. These have been noted to occur infrequently. In large published studies, the frequency of events including anaphylactic-like (allergic) reactions has been less than 0.1 percent.

The Vitrase labeling warns against using the drug where it could cause harmful effects. The warnings state that Vitrase should not be used to reduce the swelling of bites, stings, and infected or inflamed areas because of the possibility of spreading a localized infection.

Ista Pharmaceuticals, Inc., Irvine , Calif. will coordinate the manufacture and distribution of Vitrase.

For more info on this topic please review: Vartanian AJ et al. Injected hyaluronidase reduces restylane-mediated cutaneous augmentation.Arch Facial Plast Surg2005 Jul/Aug; 7:231-7.

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