Information for Healthcare Professionals: Naltrexone Injection Site Reactions [naltrexone for extended-release injectable suspension (marketed as Vivitrol)]
FDA ALERT [08/12/2008]: FDA is notifying healthcare professionals of the risk of adverse injection site reactions in patients receiving naltrexone (Vivitrol). Physicians should instruct patients to monitor the injection site and contact them if they develop pain, swelling, tenderness, induration, bruising, pruritus, or redness at the injection site that does not improve or worsens within two weeks. Physicians should promptly refer patients with worsening injection site reactions to a surgeon.
FDA has received 196 reports of injection site reactions including cellulitis, induration, hematoma, abscess, sterile abscess, and necrosis. 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.
Naltrexone is indicated for the treatment of alcohol dependence in patients who are able to abstain from alcohol in an outpatient setting prior to initiation of treatment. Naltrexone is administered as an intramuscular (IM) gluteal injection. Naltrexone should not be administered intravenously, subcutaneously, or inadvertently into fatty tissue. Healthcare providers should ensure that the naltrexone injection is given correctly with the pre-packaged 1½-inch needle that is specifically designed for this drug.
This information reflects FDA's current analysis of data available to FDA concerning naltrexone (Vivitrol). FDA intends to update this sheet when additional information or analyses become available.
To report any unexpected adverse or serious events associated with the use of naltrexone (Vivitrol), please contact the FDA MedWatch program either online, by regular mail or by fax, using the contact information at the bottom of this sheet.
FDA is working with the maker of naltrexone to add stronger and more prominent warnings in the Vivitrol prescribing information about the risk of serious adverse injection site reactions.
Recommendations and Information for Healthcare Professionals to Consider Regarding Naltrexone Injection:
- 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 (IM), 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.
Information for Healthcare Professionals to Provide When Counseling Patients:
- Vivitrol injections 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.
- If an injection site reaction does not improve within two weeks following the injection, or if it worsens sooner than 2 weeks, see your doctor.
FDA approved Vivitrol in April 2006 for the treatment of alcohol dependence, as part of a comprehensive management program that includes psychosocial support. FDA is now working with the maker of Vivitrol to make changes to the prescribing information based on post-marketing adverse event reports of injection site reactions.
FDA has reviewed 196 reports of injection site reactions including abscess, necrotic abscess, necrotic hematoma, cellulitis, and fat necrosis, reported following the administration of Vivitrol. Sixteen of the reports indicated that patients required surgical intervention ranging from incision and drainage in the cases of abscesses to extensive surgical debridement in the case that resulted in tissue necrosis. These wounds may or may not test positive for bacteria when cultured.
Naltrexone is administered as an intramuscular gluteal injection. Vivitrol must not be administered intravenously, subcutaneously, or administered inadvertently into fatty tissue. Healthcare providers should ensure that the Vivitrol injection is given correctly with the pre-packaged 1½-inch needle that is specifically designed for this drug. The risk of injection site reactions may be increased if Vivitrol is administered subcutaneously or inadvertently into fatty tissue.
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