Letter to the Editor: Would Cannabidiol Be a Therapeutic Alternative to Treat Monkeypox Symptoms?

Dear Editor:

The world is facing a public health emergency of international concern associated with the spread of monkeypox (MPX), a zoonotic virus member of the Orthopoxvirus genus in the family Poxviridae, similar to smallpox. At the time of writing this article, at least 49,000 cases and 13 deaths were registered, most of them in Europe, the United States, Canada, Peru, and Brazil.

Although the smallpox vaccine can induce cross-protective antibodies to MPX, ¹ smallpox eradication in the 1970s and the subsequent lack of vaccination efforts allowed the spread of this zoonotic disease to nonendemic regions. Some countries, including Canada, France, the United Kingdom, and the United States, have used stockpiles of smallpox vaccines in a “ring vaccination” strategy to protect individuals from close contact with a person who is infected with MPX. In addition, an MPX vaccine (produced by Bavarian Nordic™) has been available for use in the United States and Europe. However, the availability of this vaccine is currently limited, and mass vaccination is not a consensus. In July 2022, the European Medicines Agency approved the use of Tecovirimat for MPX.

In susceptible individuals, the incubation period for most MPX cases occurs within 21 days after exposure, in which its viral particles are transmitted from one person to another particularly by close skin-to-skin contact. Most cases begin as whitish solid papules on the anogenital area, face, arms/hands, which may progress to a necrotic center. In some patients, primary lesions may present as chancriform ulcers in the oral cavity, pharynx, and rectum. Moreover, systemic symptoms, including lymphadenopathy, fever, myalgia, asthenia, and headache, are common. Although the majority of infections are self-limiting within 2–4 weeks, severe cases have been associated with a cytokine storm and an increased release of interleukin (IL)-1β, IL-1RA, IL-2R, IL-4, IL-5, IL-6, IL-8, IL-13, IL-15, IL-17, monocyte chemoattractant protein-1, and regulated upon activation, normal T cell expressed and presumably secreted, especially granulocyte-macrophage colony-stimulating factor, IL-10, and serum-soluble interleukin-2 receptor. ²

The development of therapeutic alternatives is critical for reducing the hyperinflammatory state and controlling symptoms in patients infected with MPX. Because of its immunomodulatory and anti-inflammatory properties, cannabidiol (CBD) emerges as a potential candidate to alleviate MPX symptoms. CBD has been shown to lower serum concentrations of IL-4, IL-5, IL-6, and IL-13 in mice ³ and to modulate the endocannabinoid system by activating CB receptor 2 expressed in lymphoid tissue, resulting in cytokine storm inhibition and inflammation reduction. ⁴ In a recent systematic review, ⁵ it was found 11 clinical trials evaluating the efficacy and safety of systemic and topical CBD formulations for treating inflammatory skin disorders, including systemic sclerosis, dermatomyositis, and atopic dermatitis. These studies have suggested that CBD may be effective in treating skin dryness, pruritus, erythema, pain, and wound closure/healing.

However, studies to assess the efficacy and safety of CBD as a therapeutic option for treating MPX symptoms are lacking. Further high-quality trial evidence is needed.