From the Guidelines
Low-dose naltrexone (LDN) can cause side effects such as headache, tachycardia, and vivid dreams, as reported in a 2017 study published in Ophthalmology 1. These side effects are generally mild and may resolve on their own as the body adjusts to the medication. Some key points to consider about LDN side effects include:
- Common side effects: headache, tachycardia, and vivid dreams
- Recommended dosage: 1.5 mg at bedtime with gradual bi-weekly increase of 1.5 mg to a final maximum dose of 4.5 mg taken at bedtime
- LDN has been shown to be effective in reducing pain and improving satisfaction with life in patients with chronic neuropathic pain, including fibromyalgia and painful diabetic neuropathy 1. It is essential to note that LDN is an opioid antagonist, and its use may interact with opioid medications, so patients should consult their healthcare provider before starting treatment. Overall, the benefits of LDN in managing chronic neuropathic pain often outweigh the risks of side effects, and patients can work with their healthcare provider to minimize any adverse reactions.
From the FDA Drug Label
ADVERSE REACTIONS ... In an open label safety study with approximately 570 individuals with alcoholism receiving naltrexone hydrochloride, 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%) Reported Adverse Events ... 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 Postmarketing Experience ... Events that have been reported include anorexia, asthenia, chest pain, fatigue, headache, hot flushes, malaise, changes in blood pressure, agitation, dizziness, hyperkinesia, nausea, vomiting, tremor, abdominal pain, diarrhea, palpitations, myalgia, anxiety, confusion, euphoria, hallucinations, insomnia, nervousness, somnolence, abnormal thinking, dyspnea, rash, increased sweating, vision abnormalities, and idiopathic thrombocytopenic purpura.
The side effects of low-dose naltrexone can include:
- Gastrointestinal symptoms: nausea, vomiting, abdominal cramps, diarrhea
- Nervous system symptoms: headache, dizziness, nervousness, fatigue, insomnia, anxiety, somnolence
- Musculoskeletal symptoms: bone or joint pain, myalgia
- Other symptoms: restlessness, tearfulness, nasal symptoms, hot flushes, malaise, changes in blood pressure, agitation, hyperkinesia, tremor, palpitations, confusion, euphoria, hallucinations, abnormal thinking, dyspnea, rash, increased sweating, vision abnormalities 2
From the Research
Side Effects of Low-Dose Naltrexone
The side effects of low-dose naltrexone (LDN) can vary, but some common effects have been reported in various studies.
- Neurological complaints, such as headache and dizziness, were experienced by 58 patients in a study of 121 patients treated with LDN for gastrointestinal disorders 3.
- Gastrointestinal side effects, including nausea, were reported by 32 patients in the same study 3.
- Other side effects, such as arthralgia, have been reported in patients taking naltrexone for alcohol dependence, although it is not clear if these effects occur at low doses 4.
Frequency and Severity of Side Effects
- In the study of 121 patients with gastrointestinal disorders, 61.2% of patients experienced side effects, while 38.8% had no side effects 3.
- Of the patients who experienced side effects, 32.4% had short-lived symptoms, and 27.0% had to terminate LDN treatment due to side effects 3.
- The severity of side effects can vary, with some patients experiencing mild symptoms and others experiencing more severe effects, such as marked worsening of symptoms 3.
Comparison to Standard-Dose Naltrexone
- The side effects of LDN may differ from those of standard-dose naltrexone, which is typically used to treat opioid and alcohol dependence 5, 4.
- Standard-dose naltrexone has been associated with side effects such as nausea, headache, and dizziness, although the frequency and severity of these effects may be different from those experienced with LDN 4.