Table 2.

Potential Treatment Options for Monkeypox Infection

Therapy	Mechanism of Action	Typical Dosing	Formulation	FDA Approval Status	Side Effects and Adverse Events
Cidofovir	Blocks viral DNA synthesis through competitive inhibition of DNA polymerase	5 mg/kg per dose once weekly for ≥2 doses (with concomitant probenecid)	IV; off-label: topical, intravesicular	CMV retinitis in patients with AIDS [82] (1996)	Nephrotoxicity; neutropenia; decreased intraocular pressure, nausea, vomiting
Brincidofovir	Lipid conjugate prodrug of cidofovir	4 mg/kg once weekly for 2 doses (max 200 mg/dose)	Oral	Smallpox (2021) [83]	Abdominal pain, nausea, vomiting, diarrhea, elevated liver transaminases and bilirubin
Tecovirimat	Inhibits activity of the protein VP37, which prevents creation of virions that can be released from an infected host cell, thereby preventing replication and dissemination within the host	IV: 35 to <120 kg: 200 mg q12 hours ≥120 kg: 300 mg q12 hours Oral: 40 to <120 kg: 600 mg q12 hours ≥120 kg: 600 mg q8 hours All regimens for 14 days	IV and oral (off-label topical) [84]	Smallpox (2018) [85]	IV: pain and swelling at infusion site; extravasation at infusion site; headache [86] Oral: headache, abdominal pain, nausea, vomiting
VIGIV	Passive immunity through OPXV-specific antibodies collected from pooled human plasma of persons immunized with smallpox vaccine	6000 units/kg as a single dose (up to 9000 units/kg) Dose can be repeated depending upon symptoms	IV	Complications of vaccinia vaccination (progressive vaccinia, severe generalized vaccinia, etc) (2005) [87]	Infusion reaction; local injection-site reaction (contraindicated in persons with IgA deficiency and possible IgA hypersensitivity)

Abbreviations: AIDS, acquired immunodeficiency syndrome; CMV, cytomegalovirus; DNA, deoxyribonucleic acid; FDA, US Food and Drug Administration; IgA, immunoglobulin A; IV, intravenous; Max, maximum; VIGIV, vaccinia immunoglobulin intravenous.