Vivitrol (generic: naltrexone), a drug used to treat alcohol addiction, has been causing serious injection site reactions, the Food & Drug Administration (FDA) warned today.  Among the serious problems linked to  are Vivitrol are abscesses requiring surgical drainage.

Vivitrol is manufactured by Alkermes, Inc., and is marketed by Cephalon, Inc.  Vivitrol was approved in 2006 for the  treatment of alcohol dependence in patients who are able to abstain from alcohol in an outpatient setting prior to initiation of treatment.  Vivitrol is an extended release medication, and is administered via intramuscular gluteal injection once a month.

According to the FDA, there have been 196 reports of injection site reactions including cellulitis, induration, hematoma, abscess, sterile abscess, and necrosis following Vivitrol administration. Sixteen patients required surgical intervention ranging from incision and drainage in the cases of abscesses to extensive surgical debridement in the cases that resulted in tissue necrosis.

The FDA said healthcare providers should consider the following information when administering Vivitrol:

• Serious injections site reactions requiring surgical intervention, including abscesses requiring incision and drainage and cases of tissue necrosis requiring extensive surgical debridement, can occur following administration of Vivitrol. Physicians who administer Vivitrol should refer a patient who develops pain, swelling, bruising, pruritus, and redness at the injection site that does not improve within 2 weeks of Vivitrol administration to a surgeon.
• Vivitrol should be administered intramuscularly, alternating buttocks, using the specially designed needle provided. Vivitrol should not be administered intravenously or subcutaneously. The risk of serious injection site reactions may be increased when Vivitrol is deposited in subcutaneous or fatty tissue.
• Vivitrol comes with a specially designed 1½-inch-inch needle. Health care providers should ensure that the Vivitrol injection is given correctly, and should consider alternate treatment for those patients whose body habitus precludes a gluteal intramuscular injection with the provided needle. Note that the needle provided is not a standard needle. It is not possible to substitute a standard needle of a longer length.
• Data shows that there is a variable depth of subcutaneous tissue dependent on the gender and weight of the patient. Women may be physiologically at higher risk for injection site reactions due to typically higher gluteal fat thickness.

The FDA said physicians should advise their patients that administration of Vivitrol may be followed by pain, redness, itching, bruising, and swelling.  Sometimes reactions at the injection site can quickly worsen and skin and other tissue can be permanently damaged and require surgery.  Patients should be told to contact  their doctor if an injection site reaction does not improve within two weeks following the injection, or if it worsens sooner than 2 weeks.

The FDA said it is working with the maker of Vivitrol to make changes to the prescribing information based on post-marketing adverse event reports of injection site reactions.

This entry was posted on Tuesday, August 12th, 2008 at 12:48 pm and is filed under Pharmaceuticals.