^ Pharmacodynamics
Naltrexone has few, if any, intrinsic actions besides its opioid blocking properties. However, it does produce some pupillary constriction, by an unknown mechanism.
The administration of VIVITROL is not associated with the development of tolerance or dependence. In subjects physically dependent on opioids, VIVITROL will precipitate withdrawal symptomatology.
Occupation of opioid receptors by naltrexone may block the effects of endogenous opioid peptides. It markedly attenuates or completely blocks, reversibly, the subjective effects of exogenous opioids. The neurobiological mechanisms responsible for the reduction in alcohol consumption observed in alcohol-dependent patients treated with naltrexone are not entirely understood. However, involvement of the endogenous opioid system is suggested by preclinical data.
Naltrexone blocks the effects of opioids by competitive binding at opioid receptors. This makes the blockade produced potentially surmountable, but overcoming full naltrexone blockade by administration of opioids may result in non-opioid receptor-mediated symptoms such as histamine release.
VIVITROL is not aversive therapy and does not cause a disulfiram-like reaction either as a result of opioid use or ethanol ingestion.
^ Intramuscular Injections
As with any intramuscular injection, VIVITROL should be administered with caution to patients with thrombocytopenia or any coagulation disorder (e.g., hemophilia and severe hepatic failure).
^ Patient Counseling Information
Advise the patient to read the FDA-Approved patient labeling (Medication Guide).
Physicians should include the following issues in discussions with patients for whom they prescribe VIVITROL.
VIVITROL for Opioid Use Disorder:
VIVITROL for All Indications:
^ Interference With Laboratory Tests
VIVITROL may be cross-reactive with certain immunoassay methods for the detection of drugs of abuse (specifically opioids) in urine. For further information, reference to the specific immunoassay instructions is recommended.
^ Description
VIVITROL® (naltrexone for extended-release injectable suspension) is supplied as a microsphere formulation of naltrexone for suspension, to be administered by deep intramuscular injection by a healthcare practitioner. VIVITROL contains naltrexone base anhydrous as the active pharmaceutical ingredient. Naltrexone is an opioid antagonist with little, if any, opioid agonist activity.
Naltrexone is morphinan-6-one, 17-(cyclopropylmethyl)-4,5-epoxy-3,14-dihydroxy-(5α) (CAS Registry # 16590-41-3). The molecular formula is C20H23NO4 and its molecular weight is 341.41 in the anhydrous form (ie, < 1% maximum water content). The structural formula is:
Naltrexone base anhydrous is an off-white to a light tan powder with a melting point of 168 °C to 170 °C (334 °F to 338 °F). It is insoluble in water and is soluble in ethanol.
VIVITROL is provided in a carton containing one vial of VIVITROL microspheres, one vial of diluent, one 5-mL syringe, one 1-inch 20-gauge preparation needle, two 1 1/2-inch 20-gauge, and two 2-inch 20-gauge administration needles with needle protection device.
VIVITROL microspheres consist of a sterile, off-white to light tan powder that is available in a dosage strength of 380 mg of naltrexone per vial. Naltrexone base anhydrous is incorporated in a biodegradable matrix of 75:25 polylactide-co-glycolide (PLG) at a concentration of 337 mg of naltrexone per gram of microspheres.
The diluent is a clear, colorless solution. Each mL of diluent contains 30.0 mg of carboxymethylcellulose sodium, 1.0 mg of polysorbate 20, 9.0 mg of sodium chloride, and sodium hydroxide and hydrochloric acid as pH adjusters, in water for injection. The pH of the diluent is in the range of 5.8 to 7.2.
^ Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
In all controlled and uncontrolled trials during the premarketing development of VIVITROL, more than 1100 patients with alcohol and/or opioid dependence have been treated with VIVITROL. Approximately 700 patients have been treated for 6 months or more, and more than 400 for 1 year or longer.
^ Hepatic Impairment
The pharmacokinetics of VIVITROL are not altered in subjects with mild to moderate hepatic impairment (Groups A and B of the Child-Pugh classification). Dose adjustment is not required in subjects with mild or moderate hepatic impairment. VIVITROL pharmacokinetics were not evaluated in subjects with severe hepatic impairment [see Clinical Pharmacology (12.3)].
^ Overdosage
There is limited experience with overdose of VIVITROL. Single doses up to 784 mg were administered to 5 healthy subjects. There were no serious or severe adverse events. The most common effects were injection site reactions, nausea, abdominal pain, somnolence, and dizziness. There were no significant increases in hepatic enzymes.
In the event of an overdose, appropriate supportive treatment should be initiated.
^ Renal Impairment
Pharmacokinetics of VIVITROL are not altered in subjects with mild renal insufficiency (creatinine clearance of 50-80 mL/min). Dose adjustment is not required in patients with mild renal impairment. VIVITROL pharmacokinetics have not been evaluated in subjects with moderate and severe renal insufficiency. Because naltrexone and its primary metabolite are excreted primarily in the urine, caution is recommended in administering VIVITROL to patients with moderate to severe renal impairment [see Clinical Pharmacology (12.3)].
^3 Dosage Forms And Strengths
VIVITROL is an off-white to light tan powder for injectable suspension in a 5 mL single-dose vial.
VIVITROL contains 380 mg of naltrexone in a microsphere formulation per vial (337 mg of naltrexone per gram of microspheres).
^ Switching From Oral Naltrexone
There are no systematically collected data that specifically address the switch from oral naltrexone to VIVITROL.
^ Pediatric Use
The safety and efficacy of VIVITROL have not been established in the pediatric population. The pharmacokinetics of VIVITROL have not been evaluated in a pediatric population.
^ Depression And Suicidality
Alcohol- and opioid-dependent patients, including those taking VIVITROL, should be monitored for the development of depression or suicidal thinking. Families and caregivers of patients being treated with VIVITROL should be alerted to the need to monitor patients for the emergence of symptoms of depression or suicidality, and to report such symptoms to the patient's healthcare provider.
^ Hypersensitivity Reactions Including Anaphylaxis
Cases of urticaria, angioedema, and anaphylaxis have been observed with use of VIVITROL in the clinical trial setting and in postmarketing use. Patients should be warned of the risk of hypersensitivity reactions, including anaphylaxis. In the event of a hypersensitivity reaction, patients should be advised to seek immediate medical attention in a healthcare setting prepared to treat anaphylaxis. The patient should not receive any further treatment with VIVITROL.
^4 Contraindications
VIVITROL is contraindicated in:
^ How Supplied/storage And Handling
VIVITROL (naltrexone for extended-release injectable suspension) is supplied in cartons (NDC 65757-300-01). Each carton contains:
VIVITROL must be prepared and administered by a healthcare provider.
^ Injection Site Reactions
VIVITROL must be prepared and administered by a healthcare provider.
VIVITROL must ONLY be administered as a deep intramuscular gluteal injection.
VIVITROL injections may be followed by pain, tenderness, induration, swelling, erythema, bruising, or pruritus; however, in some cases injection site reactions may be very severe. In the clinical trials, one patient developed an area of induration that continued to enlarge after 4 weeks, with subsequent development of necrotic tissue that required surgical excision. In the postmarketing period, additional cases of injection site reaction with features including induration, cellulitis, hematoma, abscess, sterile abscess, and necrosis, have been reported. Some cases required surgical intervention, including debridement of necrotic tissue. Some cases resulted in significant scarring. The reported cases occurred primarily in female patients.
VIVITROL is administered as a deep intramuscular gluteal injection, and inadvertent subcutaneous injection of VIVITROL may increase the likelihood of severe injection site reactions. The needles provided in the carton are customized needles. VIVITROL must not be injected using any other needle. The needle lengths (either 1 1/2 or 2 inches) may not be adequate in every patient because of body habitus. Body habitus should be assessed prior to each injection for each patient to assure that the proper needle is selected and that the needle length is adequate for intramuscular administration. For patients with a larger amount of subcutaneous tissue overlying the gluteal muscle, the administering healthcare provider may utilize the supplied 2-inch needle with needle protection device to help ensure that the injectate reaches the intramuscular mass. For very lean patients, the 1 1/2-inch needle may be appropriate to prevent the needle contacting the periosteum. Either needle may be used for patients with average body habitus. Healthcare providers should ensure that the VIVITROL injection is given correctly, and should consider alternate treatment for those patients whose body habitus precludes an intramuscular gluteal injection with one of the provided needles.
Patients should be informed that any concerning injection site reactions should be brought to the attention of the healthcare provider [see Patient Counseling Information (17)]. Patients exhibiting signs of abscess, cellulitis, necrosis, or extensive swelling should be evaluated by a physician to determine if referral to a surgeon is warranted.
^ Precipitation Of Opioid Withdrawal
The symptoms of spontaneous opioid withdrawal (which are associated with the discontinuation of opioid in a dependent individual) are uncomfortable, but they are not generally believed to be severe or necessitate hospitalization. However, when withdrawal is precipitated abruptly by the administration of an opioid antagonist to an opioid-dependent patient, the resulting withdrawal syndrome can be severe enough to require hospitalization. Review of postmarketing cases of precipitated opioid withdrawal in association with naltrexone treatment has identified cases with symptoms of withdrawal severe enough to require hospital admission, and in some cases, management in the intensive care unit.
To prevent occurrence of precipitated withdrawal in patients dependent on opioids, or exacerbation of a pre-existing subclinical withdrawal syndrome, opioid-dependent patients, including those being treated for alcohol dependence, should be opioid-free (including tramadol) before starting VIVITROL treatment. An opioid-free interval of a minimum of 7–10 days is recommended for patients previously dependent on short-acting opioids. Patients transitioning from buprenorphine or methadone may be vulnerable to precipitation of withdrawal symptoms for as long as two weeks.
If a more rapid transition from agonist to antagonist therapy is deemed necessary and appropriate by the healthcare provider, monitor the patient closely in an appropriate medical setting where precipitated withdrawal can be managed.
In every case, healthcare providers should always be prepared to manage withdrawal symptomatically with non-opioid medications because there is no completely reliable method for determining whether a patient has had an adequate opioid-free period. A naloxone challenge test may be helpful; however, a few case reports have indicated that patients may experience precipitated withdrawal despite having a negative urine toxicology screen or tolerating a naloxone challenge test (usually in the setting of transitioning from buprenorphine treatment). Patients should be made aware of the risks associated with precipitated withdrawal and encouraged to give an accurate account of last opioid use. Patients treated for alcohol dependence with VIVITROL should also be assessed for underlying opioid dependence and for any recent use of opioids prior to initiation of treatment with VIVITROL. Precipitated opioid withdrawal has been observed in alcohol-dependent patients in circumstances where the prescriber had been unaware of the additional use of opioids or co-dependence on opioids.
^ Geriatric Use
In trials of alcohol-dependent subjects, 2.6% (n=26) of subjects were >65 years of age, and one patient was >75 years of age. Clinical studies of VIVITROL did not include sufficient numbers of subjects age 65 and over to determine whether they respond differently from younger subjects. No subjects over age 65 were included in studies of opioid-dependent subjects. The pharmacokinetics of VIVITROL have not been evaluated in the geriatric population.
This drug is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, it may be useful to monitor renal function.
^ Hepatotoxicity
Cases of hepatitis and clinically significant liver dysfunction were observed in association with VIVITROL exposure during the clinical development program and in the postmarketing period. Transient, asymptomatic hepatic transaminase elevations were also observed in the clinical trials and postmarketing period. Although patients with clinically significant liver disease were not systematically studied, clinical trials did include patients with asymptomatic viral hepatitis infections. When patients presented with elevated transaminases, there were often other potential causative or contributory etiologies identified, including pre-existing alcoholic liver disease, hepatitis B and/or C infection, and concomitant usage of other potentially hepatotoxic drugs. Although clinically significant liver dysfunction is not typically recognized as a manifestation of opioid withdrawal, opioid withdrawal that is precipitated abruptly may lead to systemic sequelae including acute liver injury.
Patients should be warned of the risk of hepatic injury and advised to seek medical attention if they experience symptoms of acute hepatitis. Use of VIVITROL should be discontinued in the event of symptoms and/or signs of acute hepatitis.
^ Patient Access To Naloxone For The Emergency Treatment Of Opioid Overdose
Discuss the availability of naloxone for the emergency treatment of opioid overdose with the patient and caregiver, at the initial VIVITROL injection and with each subsequent injection. Because patients being treated for opioid use disorder have the potential for relapse, putting them at risk for opioid overdose after VIVITROL treatment is discontinued, at the end of the VIVITROL dosing interval (i.e., near the end of the month that VIVITROL was administered), or after a dose of VIVITROL is missed, strongly consider prescribing naloxone for the emergency treatment of opioid overdose [see Warnings and Precautions (5.1)].
Inform patients and caregivers of their options for obtaining naloxone as permitted by individual state naloxone dispensing and prescribing requirements or guidelines (e.g., by prescription, directly from a pharmacist, or as part of a community-based program) [see Patient Counseling Information (17)].
^ Carcinogenesis, Mutagenesis, Impairment Of Fertility
Carcinogenesis: Carcinogenicity studies have not been conducted with VIVITROL.
Carcinogenicity studies of oral naltrexone hydrochloride (administered via the diet) have been conducted in rats and mice.
In a two-year carcinogenicity study in rats, there were small increases in the numbers of testicular mesotheliomas in males and tumors of vascular origin in males and females. The incidence of testicular mesothelioma in males given naltrexone at a dietary dose of 100 mg/kg/day (3-times the human exposure based on an AUC(0-28d) comparison) was 6%, compared with a maximum historical incidence of 4%. The incidence of vascular tumors in males and females given dietary doses of 100 mg/kg/day was 4% but only the incidence in females was increased compared with a maximum historical control incidence of 2% (3 and 32 times the human exposure based on an AUC(0-28d) comparison in males and females, respectively). There was no evidence of carcinogenicity in a 2-year dietary study with naltrexone in male and female mice (12 and 3 times the human exposure based on an AUC(0-28d) comparison, respectively). The clinical significance of these findings is not known.
Mutagenesis: Naltrexone was negative in the following in vitro genotoxicity studies: bacterial reverse mutation assay (Ames test), the heritable translocation assay, CHO cell sister chromatid exchange assay, and the mouse lymphoma gene mutation assay. Naltrexone was also negative in an in vivo mouse micronucleus assay. In contrast, naltrexone tested positive in the following assays: Drosophila recessive lethal frequency assay, non-specific DNA damage in repair tests with E. coli and WI-38 cells, and urinalysis for methylated histidine residues.
Impairment of Fertility: Daily oral administration of naltrexone caused a significant increase in pseudopregnancy and a decrease in pregnancy rates in rats at 100 mg/kg/day (75 times the human exposure based on an AUC(0-28d) comparison). There was no effect on male fertility at this dose level (6 times the human exposure based on an AUC(0-28d) comparison). The relevance of these observations to human fertility is not known.
^ Directions For Use
VIVITROL must be prepared and administered by a healthcare provider.
VIVITROL must ONLY be administered as a deep intramuscular gluteal injection.
To ensure proper dosing, it is important that you follow the preparation and administration instructions outlined in this document.
VIVITROL must be suspended only in the diluent supplied in the carton and must be administered only with one of the administration needles supplied in the carton. The microspheres, diluent, preparation needle, and an administration needle with needle protection device are required for preparation and administration. Two thin-walled 1 1/2-inch needles with needle protection device and two 2-inch thin-walled needles with needle protection device have been provided to accommodate varying patient body habitus. For patients with a larger amount of subcutaneous tissue overlying the gluteal muscle, the administering healthcare provider may utilize the supplied 2-inch needle with needle protection device to help ensure that the injectate reaches the intramuscular mass. For very lean patients, the 1 1/2-inch needle may be appropriate to prevent the needle contacting the periosteum. Either needle may be used for patients with average body habitus. A spare administration needle of each size is provided in case of clogging [see How Supplied/Storage and Handling (16)]. Do not substitute any other components for the components of the carton.
Prior to preparation, allow drug to reach room temperature (approximately 45 minutes).
Parenteral products should be visually inspected for particulate matter and discoloration prior to administration whenever solution and container permit. A properly mixed suspension will be milky white, will not contain clumps, and will move freely down the wall of the vial [see Directions for Use, illustration below].
Keep out of reach of children.
Prepare and administer the VIVITROL suspension using aseptic technique.
WARNING: To reduce the risk of a needlestick:
THE CARTON SHOULD NOT BE EXPOSED TO TEMPERATURES EXCEEDING 25 °C (77 °F).
The entire carton should be stored in the refrigerator (2 °C to 8 °C, 36 °F to 46 °F). Unrefrigerated, VIVITROL microspheres can be stored at temperatures not exceeding 25 °C (77 °F) for no more than 7 days prior to administration. Do not expose unrefrigerated product to temperatures above 25 °C (77 °F). VIVITROL should not be frozen.
^ Storage And Handling
The entire dose pack should be stored in the refrigerator (2 °C to 8 °C, 36 °F to 46 °F). Unrefrigerated, VIVITROL can be stored at temperatures not exceeding 25 °C (77 °F) for no more than 7 days prior to administration. Do not expose the product to temperatures above 25 °C (77 °F). VIVITROL should not be frozen.
Keep out of Reach of Children.
^ Switching From Buprenorphine, Buprenorphine/naloxone, Or Methadone
There are no systematically collected data that specifically address the switch from buprenorphine or methadone to VIVITROL; however, review of postmarketing case reports have indicated that some patients may experience severe manifestations of precipitated withdrawal when being switched from opioid agonist therapy to opioid antagonist therapy [see Warnings and Precautions (5.3)]. Patients transitioning from buprenorphine or methadone may be vulnerable to precipitation of withdrawal symptoms for as long as 2 weeks. Healthcare providers should be prepared to manage withdrawal symptomatically with non-opioid medications.
^ Vulnerability To Opioid Overdose
After opioid detoxification, patients are likely to have reduced tolerance to opioids. VIVITROL blocks the effects of exogenous opioids for approximately 28 days after administration. However, as the blockade wanes and eventually dissipates completely, patients who have been treated with VIVITROL may respond to lower doses of opioids than previously used, just as they would have shortly after completing detoxification. This could result in potentially life-threatening opioid intoxication (respiratory compromise or arrest, circulatory collapse, etc.) if the patient uses previously tolerated doses of opioids. Cases of opioid overdose with fatal outcomes have been reported in patients who used opioids at the end of a dosing interval, after missing a scheduled dose, or after discontinuing treatment.
Patients should be alerted that they may be more sensitive to opioids, even at lower doses, after VIVITROL treatment is discontinued, especially at the end of a dosing interval (i.e., near the end of the month that VIVITROL was administered), or after a dose of VIVITROL is missed. It is important that patients inform family members and the people closest to the patient of this increased sensitivity to opioids and the risk of overdose [see Patient Counseling Information (17)].
There is also the possibility that a patient who is treated with VIVITROL could overcome the opioid blockade effect of VIVITROL. Although VIVITROL is a potent antagonist with a prolonged pharmacological effect, the blockade produced by VIVITROL is surmountable. The plasma concentration of exogenous opioids attained immediately following their acute administration may be sufficient to overcome the competitive receptor blockade. This poses a potential risk to individuals who attempt, on their own, to overcome the blockade by administering large amounts of exogenous opioids. Any attempt by a patient to overcome the antagonism by taking opioids is especially dangerous and may lead to life-threatening opioid intoxication or fatal overdose. Patients should be told of the serious consequences of trying to overcome the opioid blockade [see Patient Counseling Information (17)].
^ Reinitiation Of Treatment In Patients Previously Discontinued
There are no data to specifically address reinitiation of treatment. Patients reinitiating treatment with VIVITROL should be opioid-free at the time of dose administration [see Indications and Usage (1), Contraindications (4), and Warnings and Precautions (5.3)].
^ Important Dosage And Administration Information
VIVITROL must be prepared and administered by a healthcare provider.
VIVITROL must ONLY be administered as a deep intramuscular gluteal injection.
Parenteral products should be visually inspected for particulate matter and discoloration prior to administration whenever solution and container permit. A properly mixed suspension will be milky white, will not contain clumps, and will move freely down the wall of the vial [see Dosage and Administration (2.6)].
Prior to initiating VIVITROL, an opioid-free duration of a minimum of 7–10 days is recommended for patients, to avoid precipitation of opioid withdrawal that may be severe enough to require hospitalization [see Warnings and Precautions (5.3)].
The recommended dose of VIVITROL is 380 mg delivered intramuscularly (deep) as a gluteal injection every 4 weeks or once a month, alternating buttocks for each subsequent injection, using the carton components provided [see How Supplied/Storage and Handling (16)]. The needles provided in the carton are customized needles. VIVITROL must not be injected using any other needle. The needle lengths (either 1 1/2 or 2 inches) may not be adequate in every patient because of body habitus. Body habitus should be assessed prior to each injection for each patient to assure that needle length is adequate for intramuscular administration. For patients with a larger amount of subcutaneous tissue overlying the gluteal muscle, the administering healthcare provider may utilize the supplied 2-inch needle with needle protection device to help ensure that the injectate reaches the intramuscular mass. For very lean patients, the 1 1/2-inch needle may be appropriate to prevent the needle contacting the periosteum. Either needle may be used for patients with average body habitus. Healthcare providers should ensure that the VIVITROL injection is given correctly, and should consider alternate treatment for those patients whose body habitus precludes an intramuscular gluteal injection with one of the provided needles.
^ Eosinophilic Pneumonia
In clinical trials with VIVITROL, there was one diagnosed case and one suspected case of eosinophilic pneumonia. Both cases required hospitalization, and resolved after treatment with antibiotics and corticosteroids. Similar cases have been reported in postmarketing use. Should a person receiving VIVITROL develop progressive dyspnea and hypoxemia, the diagnosis of eosinophilic pneumonia should be considered [see Adverse Reactions (6)]. Patients should be warned of the risk of eosinophilic pneumonia, and advised to seek medical attention should they develop symptoms of pneumonia. Clinicians should consider the possibility of eosinophilic pneumonia in patients who do not respond to antibiotics.
^6 Adverse Reactions
The following clinically significant adverse reactions are described elsewhere in the labeling:
^ When Reversal Of Vivitrol Blockade Is Required For Pain Management
In an emergency situation in patients receiving VIVITROL, suggestions for pain management include regional analgesia or use of non-opioid analgesics. If opioid therapy is required as part of anesthesia or analgesia, patients should be continuously monitored in an anesthesia care setting by persons not involved in the conduct of the surgical or diagnostic procedure. The opioid therapy must be provided by individuals specifically trained in the use of anesthetic drugs and the management of the respiratory effects of potent opioids, specifically the establishment and maintenance of a patent airway and assisted ventilation.
Irrespective of the drug chosen to reverse VIVITROL blockade, the patient should be monitored closely by appropriately trained personnel in a setting equipped and staffed for cardiopulmonary resuscitation.
^7 Drug Interactions
Patients taking VIVITROL may not benefit from opioid-containing medicines. Naltrexone antagonizes the effects of opioid-containing medicines, such as cough and cold remedies, antidiarrheal preparations and opioid analgesics.
^ Frequently Asked Questions About Administering Vivitrol:
For additional information, visit www.vivitrol.com or call 1-800-848-4876
Manufactured and marketed by:Alkermes, Inc.Waltham, MA 02451
©2024 Alkermes. All rights reserved.ALKERMES® and VIVITROL® are registered trademarks of Alkermes, Inc.Printed in U.S.A.REV: January 2024
US Patent No. 7,919,499
^ Alcohol Withdrawal
Use of VIVITROL does not eliminate nor diminish alcohol withdrawal symptoms.
^ Opioid Dependence
VIVITROL is indicated for the prevention of relapse to opioid dependence, following opioid detoxification.
^ Alcohol Dependence
VIVITROL 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 with VIVITROL. Patients should not be actively drinking at the time of initial VIVITROL administration.
^1 Indications And Usage
Treatment with VIVITROL should be part of a comprehensive management program that includes psychosocial support.
^ Mechanism Of Action
Naltrexone is an opioid antagonist with highest affinity for the mu opioid receptor. Naltrexone has little or no opioid agonist activity.