From the Guidelines
Muscle cramps and fatigue are not commonly reported side effects of naltrexone, but they can occur in some patients. According to the study published in Gastroenterology in 2017 1, the most common side effects of naltrexone/bupropion include nausea, constipation, headache, dizziness, insomnia, and dry mouth. However, muscle cramps and fatigue are not explicitly mentioned as common side effects in this study. Some key points to consider when evaluating the potential for muscle cramps and fatigue as side effects of naltrexone include:
- The study focused on the use of naltrexone/bupropion for obesity treatment, and the side effect profile may vary depending on the specific indication and patient population.
- The study did not report on muscle cramps and fatigue specifically, but it did note that patients using naltrexone/bupropion demonstrated significant weight loss and improvements in hemoglobin A1c levels.
- In clinical practice, patients taking naltrexone may experience a range of side effects, and muscle cramps and fatigue could potentially occur, particularly during the initial weeks of treatment. It is essential to monitor patients taking naltrexone for any adverse effects, including muscle cramps and fatigue, and to adjust the treatment plan as needed to minimize these symptoms and optimize treatment outcomes.
From the FDA Drug Label
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: ... fatigue (4%) 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%: ... low energy, joint and muscle pain Postmarketing Experience Data collected from postmarketing use of naltrexone show that most events usually occur early in the course of drug therapy and are transient. ... Events that have been reported include ... fatigue, myalgia
Muscle cramps and fatigue are potential side effects of naltrexone.
- Fatigue has been reported in clinical trials and postmarketing experience, with an incidence rate of 4% in an open-label safety study of approximately 570 individuals with alcoholism receiving naltrexone 2.
- Muscle cramps are not explicitly mentioned, but joint and muscle pain have been reported in opioid addiction clinical trials, and myalgia has been reported in postmarketing experience 2. Note that the FDA label does not explicitly mention muscle cramps as a side effect, but it does mention related symptoms such as joint and muscle pain, and myalgia 2 and 2.
From the Research
Side Effects of Naltrexone
- Muscle cramps and fatigue are potential side effects of various medications, but the provided studies do not directly link these side effects to naltrexone in all cases.
- According to 3, common side effects of naltrexone include nausea, headache, dizziness, and arthralgia, but muscle cramps and fatigue are not explicitly mentioned.
- However, 4 discusses the use of low-dose naltrexone for chronic fatigue syndrome, suggesting that naltrexone may have some effect on fatigue, although this is not directly related to naltrexone-induced fatigue.
- Additionally, 5 mentions a study protocol for a trial investigating the use of low-dose naltrexone for post-COVID fatigue syndrome, further indicating a potential relationship between naltrexone and fatigue.
- The safety profile of naltrexone is discussed in 6, which reports nausea and headache as the most common adverse events, but does not mention muscle cramps or fatigue specifically.
- It is essential to note that the provided studies do not comprehensively address the question of whether muscle cramps and fatigue are side effects of naltrexone, and more research may be necessary to fully understand the relationship between naltrexone and these side effects, as seen in 7, 3, 4, 5, 6.