Safety and efficacy of low dose naltrexone in a long covid cohort; an interventional pre-post study.

Background: Up to 37.7% of patients experience symptoms beyond 12 weeks after infection with SARS-CoV-2. To date care for people with long covid has centred around multidisciplinary rehabilitation, self care and self pacing. No pharmacotherapy has been shown to be beneficial. Methods: In this single centre interventional pre post study, the safety of Low Dose Naltrexone (LDN) was explored in patients with Post COVID-19 Syndrome (PCS), defined by NICE as patients with ongoing symptoms 12 or more weeks after initial infections with SARS-CoV-2 where alternative explanation for symptoms cannot be found. Patients were recruited through a Post COVID clinic, had a baseline quality of life questionnaire in symmetrical Likert format, were prescribed 2 months (1 mg month one, 2 mg month two) of LDN and repeated the same questionnaire at the end of the second month. Patients were monitored to adverse events. Findings: In total 52 patients participated of whom 40(76.9%) were female. The median age was 43.5 years(IQR 33.2-49). Healthcare workers represented the largest occupational cohort n = 16(34.8%). The median time from diagnosis of COVID-19 until enrolment was 333 days (IQR 171-396.5). Thirty-eight participants (73.1%) were known to commence LDN, two of whom (5.3%) stopped taking LDN post commencement due to new onset diarrhoea and also described fatigue. In total 36(69.2%) participants completed the questionnaire at the end of the two-month period. Improvement was seen in 6 of 7 parameters measured; recovery from COVID-19, limitation in activities of daily living, energy levels, pain levels, levels of concentration and sleep disturbance (p ≤ 0.001), improvement in mood approached but was not significant (p = 0.054). Conclusions: LDN is safe in patients with PCS and may improve well-being and reduce symptomatology in this cohort. Randomised control trials are needed to further explore this.