Naltrexone Side Effects

Brand Names: ReVia, Revia, Vivitrol

Please note - some side effects for Naltrexone may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of Naltrexone - for the Consumer

Naltrexone

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Naltrexone:

Anxiety; appetite loss; chills; constipation; delayed ejaculation; diarrhea; dizziness; drowsiness; feeling down; headache; increased energy; increased thirst; irritability; joint and muscle pain; low energy; nausea; nervousness; sleeplessness; stomach pain/cramps; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); abdominal or stomach pain; cramping; dark urine; depression; suicidal thoughts or behaviors; unusual tiredness or weakness; vomiting; white bowel movements; yellowing of the skin or eyes.

Naltrexone Side Effects - for the Professional

Naltrexone

During two randomized, double-blind placebo-controlled 12 week trials to evaluate the efficacy of Naltrexone as an adjunctive treatment of alcohol dependence, most patients tolerated Naltrexone well. In these studies, a total of 93 patients received Naltrexone hydrochloride at a dose of 50 mg once daily. Five of these patients discontinued Naltrexone because of nausea. No serious adverse events were reported during these two trials.

While extensive clinical studies evaluating the use of Naltrexone in detoxified, formerly opioid-dependent individuals failed to identify any single, serious untoward risk of Naltrexone use, placebo-controlled studies employing up to five-fold higher doses of Naltrexone hydrochloride (up to 300 mg per day) than that recommended for use in opiate receptor blockade have shown that Naltrexone causes hepatocellular injury in a substantial proportion of patients exposed at higher doses.

Aside from this finding, and the risk of precipitated opioid withdrawal, available evidence does not incriminate Naltrexone, used at any dose, as a cause of any other serious adverse reaction for the patient who is“opioid free.” It is critical to recognize that Naltrexone can precipitate or exacerbate abstinence signs and symptoms in any individual who is not completely free of exogenous opioids.

Patients with addictive disorders, especially opioid addiction, are at risk for multiple numerous adverse events and abnormal laboratory findings, including liver function abnormalities. Data from both controlled and observational studies suggest that these abnormalities, other than the dose-related hepatotoxicity described above, are not related to the use of Naltrexone.

Among opioid free individuals, Naltrexone administration at the recommended dose has not been associated with a predictable profile of serious adverse or untoward events. However, as mentioned above, among individuals using opioids, Naltrexone may cause serious withdrawal reactions.

Reported Adverse Events:

Naltrexone has not been shown to cause significant increases in complaints in placebo-controlled trials in patients known to be free of opioids for more than 7 to 10 days. Studies in alcoholic populations and in volunteers in clinical pharmacology studies have suggested that a small fraction of patients may experience an opioid withdrawal-like symptom complex consisting of tearfulness, mild nausea, abdominal cramps, restlessness, bone or joint pain, myalgia, and nasal symptoms. This may represent the unmasking of occult opioid use, or it may represent symptoms attributable to Naltrexone. A number of alternative dosing patterns have been recommended to try to reduce the frequency of these complaints.

Alcoholism:

In an open label safety study with approximately 570 individuals with alcoholism receiving Naltrexone, the following new-onset adverse reactions occurred in 2% or more of the patients: nausea (10%), headache (7%), dizziness (4%), nervousness (4%), fatigue (4%), insomnia (3%), vomiting (3%), anxiety (2%) and somnolence (2%).

Depression, suicidal ideation, and suicidal attempts have been reported in all groups when comparing Naltrexone, placebo, or controls undergoing treatment for alcoholism.

Although no causal relationship with Naltrexone is suspected, physicians should be aware that treatment with Naltrexone does not reduce the risk of suicide in these patients.

Opioid Addiction:

The following adverse reactions have been reported both at baseline and during the Naltrexone clinical trials in opioid addiction at an incidence rate of more than 10%:

Difficulty sleeping, anxiety, nervousness, abdominal pain/cramps, nausea and/or vomiting, low energy, joint and muscle pain, and headache.

The incidence was less than 10% for:

Loss of appetite, diarrhea, constipation, increased thirst, increased energy, feeling down, irritability, dizziness, skin rash, delayed ejaculation, decreased potency, and chills.

The following events occurred in less than 1% of subjects:

Respiratory: nasal congestion, itching, rhinorrhea, sneezing, sore throat, excess mucus or phlegm, sinus trouble, heavy breathing, hoarseness, cough, shortness of breath.

Cardiovascular: nose bleeds, phlebitis, edema, increased blood pressure, non-specific ECG changes, palpitations, tachycardia.

Gastrointestinal: excessive gas, hemorrhoids, diarrhea, ulcer.

Musculoskeletal: painful shoulders, legs or knees; tremors, twitching.

Genitourinary: increased frequency of, or discomfort during, urination; increased or decreased sexual interest.

Dermatologic: oily skin, pruritus, acne, athlete's foot, cold sores, alopecia.

Psychiatric: depression, paranoia, fatigue, restlessness, confusion, disorientation, hallucinations, nightmares, bad dreams.

Special senses: eyes-blurred, burning, light sensitive, swollen, aching, strained; ears-“clogged”, aching, tinnitus.

General: increased appetite, weight loss, weight gain, yawning, somnolence, fever, dry mouth, head“pounding”, inguinal pain, swollen glands,“side” pains, cold feet,“hot spells.”

Post-marketing Experience: Data collected from post-marketing use of Naltrexone show that most events usually occur early in the course of drug therapy and are transient. It is not always possible to distinguish these occurrences from those signs and symptoms that may result from a withdrawal syndrome. Events that have been reported include anorexia, asthenia, chest pain, fatigue, headache, hot flashes, malaise, changes in blood pressure, agitation, dizziness, hyperkinesia, nausea, vomiting, tremor, abdominal pain, diarrhea, elevations in liver enzymes or bilirubin, hepatic function abnormalities or hepatitis, palpitations, myalgia, anxiety, confusion, euphoria, hallucinations, insomnia, nervousness, somnolence, abnormal thinking, dyspnea, rash, increased sweating, and vision abnormalities.

Depression, suicide, attempted suicide and suicidal ideation have been reported in the post-marketing experience with Naltrexone used in the treatment of opioid dependence. No causal relationship has been demonstrated. In the literature, endogenous opioids have been theorized to contribute to a variety of conditions. In some individuals the use of opioid antagonists has been associated with a change in baseline levels of some hypothalamic, pituitary, adrenal, or gonadal hormones. The clinical significance of such changes is not fully understood.

Adverse events, including withdrawal symptoms and death, have been reported with the use of Naltrexone in ultra rapid opiate detoxification programs. The cause of death in these cases is not known.

Laboratory Tests: With the exception of liver test abnormalities, results of laboratory tests, like adverse reaction reports, have not shown consistent patterns of abnormalities that can be attributed to treatment with Naltrexone.

Idiopathic thrombocytopenic purpura was reported in one patient who may have been sensitized to Naltrexone in a previous course of treatment with Naltrexone. The condition cleared without sequelae after discontinuation of Naltrexone and corticosteroid treatment.

Side Effects by Body System

General

General side effects have rarely included an opioid withdrawal-like symptom complex. This has been known to occur in a small number of patients receiving naltrexone. Symptoms include tearfulness, mild nausea, abdominal cramps, restlessness, bone or joint pain, myalgia, and nasal symptoms.

In one study, few symptoms were reported following the first week. However, stomach cramps, inability to sleep, and frightening thoughts were reported by 30% or more of subjects through the third week of therapy.

The effects of an opiate may be attenuated during self-administration of small doses of an opiate drug. Patients taking naltrexone may not benefit from opioid-containing medications, such as cough and cold preparations, antidiarrheal preparations, and opioid analgesics. However, patients treated with naltrexone may respond to lower doses of opioids than previously used. Patients self- administering large doses of an opiate drug could sustain serious injury (including coma) or die if high opiate plasma concentrations remain beyond the therapeutic effectiveness of naltrexone.

The opioid withdrawal-like symptom complex may be attributable to naltrexone or may represent occult opioid usage.

Nervous system

Nervous system side effects reported during treatment for alcohol dependence have included headache (7%), dizziness (4%), nervousness (4%), fatigue (4%), insomnia (3%), anxiety (2%), and somnolence (2%).

Nervous system side effects reported in greater than 10% of patients during treatment for opioid dependence have included headaches, nervousness, anxiety, difficulty sleeping, and low energy. Loss of appetite, increased energy, irritability, and dizziness have been reported in less than 10% of patients. Asthenia, agitation, hyperkinesia, nervousness, fatigue, restlessness, confusion, disorientation, and somnolence have been reported rarely.

Nervous system side effects associated with extended-release injectable solution have frequently included headache, dizziness, syncope, somnolence, insomnia, and sedation. Dysgeusia, attention disturbance, mental impairment, and convulsions have been reported rarely.

Psychiatric

Psychiatric side effects reported during treatment of alcohol dependence have included depression (up to 15%), suicidal ideation (up to 1%), and suicidal attempts.

Psychiatric side effects reported during treatment of opioid dependence have included feeling down (less than 10%). Depression, paranoia, hallucinations, bad dreams, and nightmares have been reported rarely. Anxiety and abnormal thinking have also been reported.

Psychiatric side effects associated with extended-release injectable suspension have frequently included anxiety, sleep disorder, and depression. Irritability, decreased libido, abnormal dreams, alcohol withdrawal syndrome, euphoric mood, and delirium have been reported rarely.

Depression and suicidal ideation or attempts have occurred in all study groups receiving naltrexone for treatment of alcohol dependence. These conditions also have been reported in data collected from postmarketing experience during treatment of opioid dependence.

Gastrointestinal

Gastrointestinal side effects reported during treatment for alcohol dependence have included nausea (10%) and vomiting (3%).

Gastrointestinal side effects reported in greater than 10% of patients during treatment for opioid dependence have included abdominal pain, abdominal cramps, nausea, and vomiting. Loss of appetite, diarrhea, constipation, and increased thirst have been reported in less than 10% of patients. Hemorrhoids, ulcer, diarrhea, excessive gas, increased appetite, and dry mouth have been reported rarely.

Gastrointestinal side effects associated with extended-release injectable solution have frequently included nausea, vomiting, diarrhea, abdominal pain, and dry mouth. Constipation, toothache, tooth abscess, flatulence, gastroesophageal reflux, hemorrhoids, colitis, gastrointestinal hemorrhage, paralytic ileus, gastroenteritis, and perirectal abscess have been reported rarely.

Hepatic

Hepatic side effects have included hepatocellular injury, hepatitis, and elevated liver transaminases and bilirubin.

Hepatic side effects associated with extended-release injectable suspension have rarely included cholelithiasis, increased aspartate aminotransferase (AST) level, increased alanine aminotransferase (ALT) level, and acute cholecystitis.

In clinical studies, doses greater than 50 mg a day consistently resulted in more frequent and more significant elevations of serum transaminase levels when compared to placebo.

Patients who develop liver disease from other cause or who take naltrexone in excess may be more prone to hepatocellular injury.

Musculoskeletal

Musculoskeletal side effects reported in greater than 10% of patients during treatment for opioid dependence have included joint and muscle pain. Tremors, twitching, and painful shoulders, legs or knees have been reported rarely.

Musculoskeletal side effects associated with extended-release injectable suspension have frequently included arthralgia, arthritis, joint stiffness, and muscle cramps. Limb pain, muscle spasms, and joint stiffness have been reported rarely.

Respiratory

Respiratory side effects, during treatment of opioid dependence, have rarely included: nasal congestion, itching, rhinorrhea, sneezing, sore throat, excess mucous, sinus trouble, heavy breathing, hoarseness, cough, and shortness of breath.

Respiratory side effects associated with extended-release injectable solution have frequently included upper respiratory infection and pharyngitis. Pharyngolaryngeal pain, dyspnea, sinus congestion, bronchitis, pneumonia, and chronic obstructive airways disease have been reported rarely.

Cardiovascular

Cardiovascular side effects reported during treatment of opioid dependence have rarely included nose bleeds, phlebitis, edema, increased blood pressure, EKG changes, palpitations and tachycardia.

Cardiovascular side effects associated with extended release injectable suspension have rarely included palpitations, atrial fibrillation, myocardial infarction, angina pectoris, unstable angina, congestive cardiac failure, ischemic stroke, cerebral arterial aneurysm, hypertension, deep venous thrombosis, pulmonary embolism, hot flushes, and coronary artery atherosclerosis.

Genitourinary

Genitourinary side effects reported in greater than 10% of patients during treatment of opioid dependence have included delayed ejaculation and decreased potency. Increased frequency of or discomfort during urination and increased or decreased sexual interest has been reported rarely.

Genitourinary side effects associated with extended-release injectable solution have rarely included urinary tract infection.

Dermatologic

Dermatologic side effects reported during treatment of opioid dependence have rarely included oily skin, pruritus, acne, athlete's foot, cold sores, alopecia, and rash.

Dermatologic side effects associated with extended-release injectable suspension have rarely included rash, increased sweating, night sweats, cellulitis, and pruritus.

Ocular

Ocular side effects reported during treatment of opioid dependence have rarely included blurred vision, burning, and increased sensitivity to light.

Ocular side effects associated with extended-release injectable suspension have rarely included conjunctivitis.

Other

Other side effects associated with treatment of opioid dependence have rarely included feeling of "clogged" ears, aching, and tinnitus.

Other side effects reported during treatment of opioid dependence have rarely included chills, weight loss, weight gain, yawning, fever, head "pounding", inguinal pain, swollen glands, "side" pains, cold feet, and "hot spells".

Other side effects associated with extended-release injectable suspension have frequently included asthenia and back pain/stiffness. Pyrexia, lethargy, rigors, chest pain/tightness, influenza, seasonal allergy, missed abortion, and decreased weight have been reported rarely.

Endocrine

Endocrine side effects associated with opioid antagonists have included a change in the baseline levels of hypothalamic, pituitary gland, and gonadal hormones. The clinical significance of these changes is unknown.

Other

Other side effects reported during ultra-rapid opioid detoxification programs with naltrexone have included withdrawal signs and symptoms and fatalities. The cause of death is unknown.

Hematologic

Hematologic side effects have included a single case report of idiopathic thrombocytopenic purpura. This patient may have been previously sensitized to naltrexone.

Hematologic side effects associated with extended-release injectable suspension have rarely included increased white blood cell count.

Local

Local side effects associated with extended-release injectable suspension have frequently included tenderness, pruritus, ecchymosis, nodules, swelling, and pain at injection site.

The 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.

Metabolic

Metabolic side effects associated with extended-release injectable suspension have frequently included anorexia, decreased appetite, and other appetite disorders. Increased appetite, heat exhaustion, dehydration, and hypercholesterolemia have been reported rarely.

Hypersensitivity

Hypersensitivity side effects associated with extended-release injectable solution have rarely included reactions such as angioneurotic edema and urticaria.

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