An article explaining the effect of the antiviral drug Tecovir in treating smallpox

Introduction: Tecovirib is effective in treating smallpox. It can improve skin lesions, reduce the number and severity of skin lesions, and relieve patients' pain symptoms. Tecovirib is an antiviral drug that is clinically used to treat smallpox disease in adults and children weighing at least 13kg. This drug works by blocking the cell-to-cell spread of the virus, thereby preventing the disease.

Overview of Tecovirib drug

The main clinical manifestations of monkeypox caused by monkeypox virus infection are fever, rash, and swollen lymph nodes. The monkeypox epidemic discovered in non-endemic areas in May 2022 has spread to many countries and regions around the world. In 2018, oral tecovirib was the first drug approved by the U.S. FDA to treat smallpox, and Health Canada approved it for the same indication in December 2021. On January 20, 2022, Tecovirib was approved by the European Medicines Agency for the treatment of smallpox, monkeypox, and cowpox infections. On May 19, 2022, the U.S. FDA approved the intravenous (IV) formulation of Tecovirib as an alternative for smallpox patients who cannot swallow Tecovirib oral capsules.

Mechanism of action

It is an antiviral drug that inhibits the P37 protein, which is highly conserved and present in all orthopoxviruses (such as smallpox, vaccinia virus, lepox virus, lepox virus, and monkeypox virus). The p37 protein interacts with late endosome-derived transport vesicle components. This interaction results in the formation of virus-specific encapsulation complexes that envelop virions. Thus, P37 produces virulence through the formation and release of enveloped virions. This makes Tecovirib effective in treating orthopoxviruses.

Therapeutic effect

Based on animal studies, the European Medicines Agency believes that Tecovirib can effectively reduce the mortality of smallpox, monkeypox and cowpox. In tests against multiple orthopoxviruses, including variola strains, Tecovirib showed high antiviral activity and was highly selective against orthopoxviruses, with a significant reduction in mortality. In animal models, it has been shown to be effective in increasing monkeypox virus survival when treatment is initiated after the onset of clinical symptoms of the disease.

A recent retrospective observational study reported that monkeypox patients who received tecovirib 600 mg orally twice daily had shorter viral shedding, hospitalization, and duration of illness compared with patients who received brincidofovir or no antiviral therapy.

Side Effects

Tecoverib may cause side effects such as abdominal pain, headache, nausea and vomiting during treatment. Therefore, it is recommended that patients eat a light diet during treatment, eat small meals frequently, avoid spicy and greasy foods, and eat more fruits, vegetables and legumes, such as grapes, cucumbers, green leafy vegetables, apples, tofu, etc. At the same time, keep your skin clean and dry. After sweating, you should take a shower or wipe your skin with warm water and dry it immediately with a towel. Patients and family members must wear masks and do not share clothes, tableware, toiletries, etc. to prevent mutual infection.