Study to Evaluate the Efficacy and Safety of CardiolRx™ in Patients With COVID-19 and Cardiovascular Disease or Risk Factors A Double-blind, Placebo-controlled Trial

McNamara et al., NCT04615949, NCT04615949, Jul 2025
Late treatmentDouble-blind RCT · NCT04615949 · 90 patients · USA
Cannabidiol for COVID-19
McNamara et al. NCT04615949 · July 2025
Outcome
Improvement
Relative Risk · 95% CI
00.511.52+
← Cannabidiol
reduces risk
Cannabidiol
increases risk →
Lower mortality with cannabidiol
Not statistically significant · p = 0.49
Early terminated RCT showing lower mortality with cannabidiol treatment, without statistical significance.
Standard of Care (SOC) for COVID-19 in the study country, the USA, is very poor with very low average efficacy for approved treatments1. Only expensive, high-profit treatments were approved for early treatment. Low-cost treatments were excluded, reducing the probability of early treatment due to access and cost barriers, and eliminating complementary and synergistic benefits seen with many low-cost treatments.
OutcomeImprovementEffect · pTreatmentControl
risk of death 80.0% lower · RR 0.20 · p = 0.49 80.0% lowerRR 0.20p = 0.49 0 of 45 (0.0%) 2 of 45 (4.4%) treatment 0 of 45 (0.0%), control 2 of 45 (4.4%)NNT 22continuity correction due to zero events

Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates.

McNamara et al., 25 Jul 2025, Double Blind Randomized Controlled Trial, placebo-controlled, USA, preprint, 1 author, trial NCT04615949 (history). Contact: andrea.parker@cardiolRx.com.
$0 $500 $1,000+ Efficacy vs. cost for COVID-19 treatment protocols c19early.org November 2026 USA Angola Colombia Kenya Mozambique Myanmar South Africa Peru Philippines Vietnam Japan Argentina Nepal Iran Bangladesh Ethiopia Ghana Germany Mexico South Korea United Kingdom Saudi Arabia Algeria Morocco Yemen Poland Uzbekistan India China Venezuela DR Congo Madagascar Thailand Uganda Egypt Nigeria Taiwan Fiji Zambia Bosnia-Herzegovina Jordan Georgia Switzerland Dominican Republic Bolivia Côte d'Ivoire Eritrea Togo Bulgaria Greece Slovakia Iceland New Zealand Trinidad and Tobago Mongolia Czechia Belarus Israel Haiti North Macedonia Hong Kong Qatar Panama Serbia USA favored high-profit treatments.The average efficacy of treatments was very low.High-cost protocols reduce early treatment, andforgo complementary/synergistic benefits. More effective More expensive 75% 50% 25% ≤0%
$0 $500 $1,000+ Efficacy vs. cost for COVID-19treatment protocols worldwide c19early.org November 2026 USA Angola Colombia Kenya Mozambique Myanmar South Africa Peru Philippines Vietnam Japan Argentina Nepal Iran Bangladesh Ethiopia Ghana Germany Mexico South Korea United Kingdom Saudi Arabia Algeria Morocco Yemen Poland Uzbekistan India China Venezuela DR Congo Madagascar Thailand Uganda Egypt Taiwan Fiji Zambia Jordan Georgia Switzerland Dominican Rep. Bolivia Côte d'Ivoire Eritrea Togo Sri Lanka Bulgaria Greece Slovakia New Zealand Trinidad and Tobago Mongolia Czechia Belarus Israel North Macedonia Hong Kong Qatar Panama Serbia USA favored high-profit treatments.The average efficacy was very low.High-cost protocols reduce early treatment,and forgo complementary/synergistic benefits. More effective More expensive 75% 50% 25% ≤0%
Late treatment
is less effective