Low Dose Naltrexone for Pain in Patients With HIV

Inclusion Criteria: * Age 18-75, male and female * HIV infection with a viral load of \< 1000 copies/ml for the past 12 months. (That is the viral load below which, according to the 2018 American College of Obstetricians and Gynecologists (ACOG) Committee Opinion, there is no thought of a significant risk of HIV transmission from the mother to the fetus with vaginal delivery. This was thought to be a reasonable cut-off for inclusion in this study.) * Diagnosis of neuropathic pain (pain that is associated with a lesion or disease involving the somatosensory nervous system, e.g., painful neuropathy, radicular pain, complex regional pain syndrome, nerve-related pain following spine surgery, etc.) using the neuropathic pain screening tool, painDETECT17, as part of the neuropathic pain screen. * Pain score \> 4/10 on average on the NPRS lasting \> 3 months (chronic pain) * Capable of informed consent and willing to comply with the study requirements * Fluent English-speaking Exclusion Criteria: * Allergy to naltrexone (not applicable to the control group) * Current use of any opioids, up to 10 days before the start of the study (not applicable to the control group) * Pregnant women * Nursing mothers and women of childbearing potential not using contraception known to be highly effective (not applicable for the control group). Highly effective contraception methods include a combination of any two of the following during the 12-week study period: 1. Use of oral, injected, or implanted hormonal methods of contraception or; 2. Placement of an intrauterine device (IUD) or intrauterine system (IUS); 3. Barrier methods of contraception: condom or occlusive cap (diaphragm or cervical /vault caps) with spermicidal foam/gel/film/cream/vaginal suppository; 4. Total abstinence; 5. Male/female sterilization. * Bipolar disorder, schizophrenia, poorly controlled anxiety or depression * Diagnosis of liver disease, e.g. cirrhosis * Current diagnosis of either chronic kidney disease or acute kidney injury and/or a GFR \<45 at baseline * Acute viral hepatitis A, B, C * Patients who self-report as having tested positive for COVID-19 or have been diagnosed with another viral illness within the past ten days. * Patients with a known or suspected diagnosis of long-term COVID * Active drug or alcohol use disorder * People who may require opioid therapy during the duration of the study, e.g. upcoming surgery * Transportation issues interfering with return study visits (NA for the control group) * Adults unable to consent * Prisoners