Monkeypox Treatment: Medications and Therapies for Recovery
CDC has issued interim clinical guidance for the treatment of monkeypox.
Monkeypox is a rare viral disease caused by the monkeypox virus, which is a member of the Orthopoxvirus family, the same family that includes the variola virus, which causes smallpox. Monkeypox is a zoonotic disease, meaning that it can be transmitted to humans from animals, such as monkeys, rodents, and other animals. The virus was first identified in 1958, when outbreaks of the disease occurred in monkeys kept for research. In humans, monkeypox causes a disease that is similar to smallpox but generally milder, with a lower case fatality rate.
In the United States, an ongoing monkeypox outbreak has been caused by Clade IIb of the monkeypox virus, which is believed to have been imported from Nigeria. The outbreak has affected multiple states and has resulted in several hospitalizations. The Centers for Disease Control and Prevention (CDC) has issued interim clinical guidance for the treatment of monkeypox, which is based on the available evidence and expert opinion.
Supportive care and pain control are the mainstay of treatment for monkeypox. Patients with intact immune systems generally recover with supportive care and pain control. However, some patients with weakened immune systems, severe disease, or involvement of anatomic areas that might result in serious sequelae may require treatment beyond supportive care and pain control.
Currently, there is no specific treatment approved for monkeypox virus infections. However, antiviral medications developed for use in patients with smallpox may be beneficial against monkeypox. The medical countermeasures available for the treatment of monkeypox from the Strategic National Stockpile (SNS) include tecovirimat, brincidofovir, vaccinia immune globulin, and cidofovir. Clinicians should first consider tecovirimat in treating monkeypox virus infections in people. Patients should be informed about the clinical trial for tecovirimat (STOMP clinical trial) and encouraged to consider enrollment. For patients who are not eligible for STOMP or who decline to participate, tecovirimat can also be provided under an expanded access protocol.
Tecovirimat, also known as TPOXX or ST-246, is an antiviral medication that is approved by the United States Food and Drug Administration (FDA) for the treatment of smallpox in adults. Tecovirimat works by blocking the production of the virus in infected cells. It has been shown to be effective against various orthopoxviruses, including monkeypox virus, in animal studies.
The STOMP clinical trial is a National Institute of Allergy and Infectious Diseases (NIAID)-funded clinical trial to evaluate the effectiveness of tecovirimat for the treatment of monkeypox virus infections in humans. The trial is currently enrolling participants who have been diagnosed with monkeypox. The trial is designed to evaluate the safety and efficacy of tecovirimat in treating monkeypox and to compare tecovirimat with placebo. Participants will be randomly assigned to receive either tecovirimat or placebo, and will be followed for 28 days to assess their response to treatment.
In addition to tecovirimat, other medical countermeasures can be considered as additive or alternative therapy for treating monkeypox virus infections in certain situations. For example, brincidofovir, vaccinia immune globulin, and cidofovir may be considered for use in patients who experience severe disease at initial presentation to healthcare or who are at high risk for progression to severe disease. These medical countermeasures may also be considered for use in patients who experience clinically significant disease progression while receiving tecovirimat or who develop recrudescence of disease after an initial period of improvement.
Brincidofovir is another antiviral medication that may be used in the treatment of monkeypox virus infections. It works by inhibiting viral DNA synthesis and has broad-spectrum activity against DNA viruses, including smallpox and monkeypox viruses. Brincidofovir is not FDA-approved for the treatment of monkeypox virus infections, but it is available under an investigational new drug (IND) protocol. It is important to note that brincidofovir has been associated with adverse effects, such as gastrointestinal symptoms, liver function abnormalities, and decreased blood cell counts. Therefore, it should be used with caution in patients with preexisting liver or kidney disease.
Vaccinia Immune Globulin (VIG)
Vaccinia immune globulin (VIG) is a product made from the blood of people who have been vaccinated against smallpox. It contains antibodies that can neutralize the virus and is used to treat severe complications of smallpox vaccination, such as eczema vaccinatum, progressive vaccinia, and severe generalized vaccinia. VIG has also been used to treat severe monkeypox virus infections with good clinical outcomes. However, VIG is not FDA-approved for the treatment of monkeypox virus infections and is available only under an IND protocol.
Cidofovir is an antiviral medication that is approved by the FDA for the treatment of cytomegalovirus retinitis in people with AIDS and for the treatment of smallpox in people who are unable to receive smallpox vaccine. Cidofovir has been shown to be effective against monkeypox virus in vitro and in animal models, but there are limited data on its use in humans with monkeypox virus infections. Cidofovir is available commercially, but its use in monkeypox virus infections is considered off-label.
Monkeypox virus infections are a rare but potentially serious disease that require careful management. The primary approach to treating monkeypox virus infections is supportive care and pain control, which may be sufficient for most patients. However, patients who are at high risk for severe disease or who have severe disease may benefit from antiviral therapy. Currently, there is no FDA-approved treatment for monkeypox virus infections, but several medical countermeasures, including tecovirimat, brincidofovir, vaccinia immune globulin, and cidofovir, may be used under appropriate circumstances. Clinicians should be familiar with the indications, dosing, and adverse effects of these medical countermeasures and should make treatment decisions based on each patient's individual clinical and other parameters. Close collaboration between healthcare providers, public health officials, and researchers is essential for ensuring optimal outcomes for patients with monkeypox virus infections.