Naltrexone side effects

A double-blind crossover study of naltrexone (1 mg/kg/day, 2 weeks) in 13 children with autistic disorder found significant improvement over placebo with respect to both parent and teacher ratings on the CGI scale, the impulsivity-hyperactivity factor of the Connor Rating Scale, and restlessness on the Naltrexone Side Effect Rating Scale. Overall, 8 of the 13 subjects demonstrated modest improvement during the naltrexone treatment phase. No significant adverse effects of naltrexone were observed, although the bitter taste of naltrexone was a problem for some children. 

Another agent of this general type is nalmefene (47) Despite their useful characteristics, opiates display tolerance, addiction, abuse, and some toxic side effects Antagonists combat some of these effects, most notably respiratory depression and addiction Nalmefene reputedly has significant oral activity as a narcotic antagonist The synthesis of nalmefine concludes by Wittig olefination of naltrexone (46) to nalmefene (47) This molecular transformation resulted in a significant increase in oral potency as well (141... 

Naltrexone (Trexan) is the only opioid antagonist currently in use for treatment of addiction. Naloxone is used to treat opioid overdose and to test for opioid addiction but has a short half-life and is relatively ineffective orally cyclazocine s dysphoric side effects make it unacceptable (Resnick et al. 1980). Patients who are likely to continue to use naltrexone and to benefit from treatment are those who have established careers (e.g., health professionals) and family support and are well motivated. Up to 70% of such clients are abstinent at 1-year follow-up (Washton et al. 1984). Programs that utili2e additional rehabilitative services have better results than those that provide minimal services. Successful treatment is also associated with taking naltrexone... 

The therapeutic dose of acamprosate is 666 mg orally three times daily, and it is supplied as a 333 mg tablet. It can be started at the full dose in most patients without titration. It differs from disulfiram and naltrexone in that it is excreted by the kidneys without liver metabolism. Consequently, it is contraindicated in patients with severe renal impairment (creatinine clearance less than or equal to 30 mL/minute), and dose reduction is necessary when the creatinine clearance is between 30 and 50 mL/minute. The most common side effects are gastrointestinal and include nausea and diarrhea. Rates of suicidal thoughts were also increased in patients treated for 1 year with acamprosate (2.4%) versus placebo (0.8%). If necessary the total daily dose maybe decreased by 1 to 3 tablets (333-999 mg) per day to alleviate side effects. 

Naltrexone is hepatotoxic and contraindicated in patients with hepatitis or liver failure. LFTs should be monitored monthly for the first 3 months, then every 3 months. Side effects include nausea, headache, dizziness, nervousness, insomnia, and somnolence. 

The common side effects of naltrexone are nansea, headache, and dizziness. In addition, naltrexone has the potential for toxic effects on the liver and should not be used in an alcoholic with cirrhosis or other known liver disease. Because it blocks opiate receptors, patients treated with naltrexone are unable to benefit from the analgesic effects of opiates such as codeine or morphine. Naltrexone may increase serum levels of acamprosate in patients taking both medications. 

Potential side effects of naltrexone include anxiety, drowsiness, and nausea. In addition, it rarely causes a chemical hepatitis. For this reason, blood testing of liver enzymes should be conducted periodically. If any signs of naltrexone-induced hepatitis appear, it should be discontinued. Furthermore, patients should be advised that they must be totally abstinent from opiates for at least 2 weeks before using naltrexone or it can precipitate severe withdrawal symptoms. 

The drugs naltrexone and nalbuphine are semi-synthetic analogues of the analgesic morphine. Morphine is a good painkiller, but has some unpleasant side effects, the most serious of which is the likelihood of becoming addicted. 

Naltrexone can induce hepatotoxicity at doses only five times the therapeutic dose and should be used with care in patients with poor hepatic function or liver damage. Side effects of the use of naltrexone are more frequently observed than following naloxone administration. Such side effects include headache, difficulty sleeping, lethargy, increased blood pressure, nausea, sneezing, delayed ejaculation, blurred vision, and increased appetite. 

An excellent brief article on buprenorphine treatment has been provided by Taikato et al. (2005), which notes the common possible side-effects (headaches, nausea and vomiting, sweating, constipation, etc.) and drug interactions. The limited central depressant effect of buprenorphine may be compounded by alcohol and antidepressants, while the metabolism of buprenorphine can be enhanced by anticonvulsants, with therefore possibly reduced efficacy. There have been some case reports of liver toxicity from buprenorphine that is reversible if the medication is stopped (Herve et al. 2004), and often clinical guidelines will recommend that liver function tests are included in buprenorphine treatment, as they definitely should be with naltrexone. 

Side-effects Naltrexone itself has only weak and uncharacteristic side-effects, stronger effects, as seen in opioid users, are mostly the result of an acute withdrawal reaction. 

Patients taking naltrexone (trade name Trexan) must tell their health care professional because the two drugs will cancel any effects that the other has. Some other medications that reduce the effects of fentanyl are buprenorphine, dezocine, nalbuphine, and pentazoncine. These medications also can cause side effects in people who have become physically dependent on fentanyl. 

Clonidine (Catapres) is another drug used to treat opiate addiction. It can relieve the anxiety, runny nose, salivation, sweating, abdominal cramps, and muscle aches of opiate withdrawal. Side effects are dry mouth, dizziness, and drowsiness. Clonidine is initially taken at 0.8-1.2 mg a day, maintained for a few days, and then gradually decreased. Combined with the opiate blocker naltrexone, clonidine can allow a more rapid detoxification (the removal of morphine from the body). Detox in a single day can be accomplished by heavy sedation or anesthesia while giving naltrexone to an unconscious addict. This controversial method has not been studied in controlled trials. 

Opioid antagonists (Table 7.4), predominantly naloxone, are used clinically to reverse the effects of opiates in overdose or postoperative sedation. Naltrexone, which has oral bioavailability, is used for the treatment of narcotic addiction and alcohol dependence. As discussed below (Section 2.2.2.1), peripherally selective antagonists are being evaluated for treatment of constipation and other gastrointestinal side effects associated with opioid agonist use. 

Nausea is the most common side effect of naltrexone, occurring in about 10% of patients. Other side effects are headache, dizziness, nervousness, fatigue, insomnia, vomiting, anxiety, and somnolence. 

Currently, three drugs are approved in the U.S. for treatment of alcoholism disulfiram (antabuse), naltrexone (revia), and acamprosate. Disulfiram has a long history of use but has fallen into disfavor because of its side effects and problems with patient adherence to therapy. Naltrexone and acamprosate were introduced more recently. The goal of these medications is to assist the patient in maintaining abstinence. 

The anticonvulsant topiramate has also been reported to be effective in reducing binge and purge frequencies in comparison with placebo. However, bothersome side-effects such as paresthesias, impaired cognition, and renal calculi may lessen its usefulness. Naltrexone is a possible adjunct in patients who are refractory to SSRIs, especially those with comorbid alcoholism and/or self-injurious behavior. ... 

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