Homeopathy for Covid-19 in Primary Care: A structured summary of a study protocol for a randomized controlled trial

To investigate the effectiveness and safety of homeopathic medicine Natrum muriaticum (LM2) for mild cases of COVID-19 in Primary Health Care.

A randomized, two-armed (1:1), parallel, placebo-controlled, double-blind, clinical trial is being performed to test the following hypotheses: H0: homeopathic medicines = placebo (null hypothesis) vs. H1: homeopathic medicines ≠ placebo (alternative hypothesis) for mild cases of COVID-19 in Primary Care.

Setting: Primary Care of São Carlos - São Paulo - Brazil. One hundred participants aged 18 years or older, with Influenza-like symptoms and a positive RT-PCR for SARS-CoV-2. Willingness to give informed consent and to comply with the study procedures is also required. Exclusion criterium: severe acute respiratory syndrome.

Homeopathy: 1 globule of Natrum muriaticum LM2 diluted in 20 mL of alcohol 30% and dispensed in a 30 ml bottle. Placebo: 20 mL of alcohol 30% dispensed in a 30 ml bottle. Posology: one drop taken orally every 4 hours (6 doses/day) while there is fever, cough, tiredness, or pain (headache, sore throat, muscle aches, chest pain, etc.) followed by one drop every 6 hours (4 doses/day) until the fourteenth day of use. The bottle of study medication should be submitted to 10 vigorous shakes (succussions) before each dose. Posology may be changed by telemedicine, with no break in blinding. Study medication should be maintained during home isolation. According to the Primary Care protocol, the home isolation period lasts until the 10^th day after the appearance of the first symptom, or up to 72 hours without symptoms.

The primary endpoint will be time to recovery, defined as the number of days elapsed before all COVID-19 Influenza-like symptoms are recorded as mild or absent during home isolation period. Secondary measures are recovery time for each COVID-19 symptom; score of the scale created for the study (COVID-Simile Scale); medicines used during follow-up; number of days of follow-up; number of visits to emergency services; number of hospitalizations; other symptoms and Adverse Events during home isolation period.

The study Statistician generated a block randomization list, using a 1:1 ratio of the two groups (denoted as A and B) and a web-based tool ( http://www.random.org/lists ).

The clinical investigators, the statistician, the Primary Care teams, the study collaborators, and the participants will remain blinded from the identity of the two treatment groups until the end of the study.

One hundred participants are planned to be randomized (1:1) to placebo (50) or homeopathy (50).

Protocol version/date May 21, 2020. Recruitment is ongoing. First participant was recruited/included on June 29,2020. Due to recruitment adaptations to Primary Care changes, the authors anticipate the trial will finish recruiting on April 10, 2021.

COVID-Simile Study was registered at the University Hospital Medical Information Network (UMIN - https://www.umin.ac.jp/ctr/index.htm ) on June 1^st, 2020, and the trial start date was June 15, 2020. Unique ID: UMIN000040602.

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.