Dosing & Uses
Dosage Forms & Strengths
tablet
- 100mg
oral suspension
- 10mg/mL
Smallpox
Indicated for treatment of human smallpox disease caused by variola virus in adult and pediatric patients, including neonates
≥48 kg (tablet or oral suspension): 200 mg PO qWeek x 2 doses (on Days 1 and 8)
<48 kg (oral suspension): 4 mg/kg PO qWeek x 2 doses (on Days 1 and 8)
Dosage Modifications
Renal or hepatic impairment
- No dosage adjustment required with any degree of impairment
Monkeypox (Off-label)
Data are not available on efficacy in treating cases of monkeypox in people
Has shown to be effective against orthopoxviruses in in vitro and animal studies
As of June 17, 2022, the CDC is developing an emergency access investigational new drug to help facilitate use as treatment
Not currently available from the United States strategic national stockpile
State and territorial health authorities can direct requests for medical countermeasures for monkeypox treatment to the CDC Emergency Operations Center (770-488-7100)
Dosing Considerations
Limitations of use
- Not indicated for treatment of diseases other than human smallpox disease
- Effectiveness for the treatment of smallpox disease has not been determined in humans because adequate and well-controlled field trials have not been feasible, and inducing smallpox disease in humans to study the drug’s efficacy is not ethical (animal trial rule)
- Efficacy may be reduced in immunocompromised patients based on studies in immune-deficient animals
Laboratory testing
- Perform hepatic laboratory testing before initiating and during treatment, as clinically appropriate
- Perform pregnancy testing before initiating in females of childbearing potential to inform risk
Dosage Forms & Strengths
tablet
- 100mg
oral suspension
- 10mg/mL
Smallpox
Indicated for treatment of human smallpox disease caused by variola virus in adult and pediatric patients, including neonates
≥48 kg (tablet or oral suspension): 200 mg PO qWeek x 2 doses (on Days 1 and 8)
10-48 kg (oral suspension): 4 mg/kg PO qWeek x 2 doses (on Days 1 and 8)
<10 kg (oral suspension): 6 mg/kg PO qWeek x 2 doses (on Days 1 and 8)
Dosage Modifications
Renal or hepatic impairment
- No dosage adjustment required with any degree of impairment
Monkeypox (Off-label)
Data are not available on efficacy in treating cases of monkeypox in people
Has shown to be effective against orthopoxviruses in in vitro and animal studies
As of June 17, 2022, the CDC is developing an emergency access investigational new drug to help facilitate use as treatment
Not currently available from the United States strategic national stockpile
State and territorial health authorities can direct requests for medical countermeasures for monkeypox treatment to the CDC Emergency Operations Center (770-488-7100)
Dosing Considerations
Limitations of use
- Not indicated for treatment of diseases other than human smallpox disease
- Effectiveness for the treatment of smallpox disease has not been determined in humans because adequate and well-controlled field trials have not been feasible, and inducing smallpox disease in humans to study the drug’s efficacy is not ethical (animal trial rule)
- Efficacy may be reduced in immunocompromised patients based on studies in immune-deficient animals
Laboratory testing
- Perform hepatic laboratory testing before initiating and during treatment, as clinically appropriate
- Perform pregnancy testing before initiating in females of childbearing potential to inform risk
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (0)
Monitor Closely (1)
- ublituximab
ublituximab decreases effects of brincidofovir by immunosuppressive effects; risk of infection. Use Caution/Monitor.
Minor (0)
Adverse Effects
1-10%
Diarrhea (8%)
Nausea (5%)
Vomiting (4%)
Serum creatinine elevated (>1.5-3x ULN) (4%)
Abdominal pain (3%)
ALT elevated (>3 to 20x ULN) (2-3%)
Total bilirubin elevated (>1.5 to 10x ULN) (1-3%)
AST elevated (>3 to 20x ULN) (1-2%)
<2%
- General and administration site: Peripheral edema
- Metabolism and nutrition: Decreased appetite
- Musculoskeletal and connective tissue: Muscular weakness
- Nervous system: Dysgeusia
- Skin and subcutaneous tissue: Rash (ie, rash, maculopapular rash, pruritic rash)
Warnings
Black Box Warnings
Increased incidence of mortality observed in brincidofovir-treated individuals compared with placebo-treated individuals in a 24-week clinical trial when evaluated in another disease
Contraindications
None
Cautions
Increased mortality if used for longer duration
- Not indicated for use in diseases other than human smallpox
- Increased mortality observed in a randomized, placebo-controlled phase 3 trial when evaluated for another disease (CMV infection)
- Increased risk in mortality is possible if used for a duration longer than at the recommended dosage on Days 1 and 8
Elevated hepatic transaminases and bilirubin
- Elevations in ALT, AST, and total bilirubin observed
- Perform hepatic laboratory testing in all patients before starting and during treatment, as clinically appropriate
- Monitor patients who develop abnormal test results for development of severe hepatic injury
- Consider discontinuing if ALT levels remain persistently >10x ULN
- Do not give second dose if ALT elevation accompanied by clinical signs and symptoms of liver inflammation or increasing direct bilirubin, alkaline phosphatase, or INR
Diarrhea and GI adverse effects
- Diarrhea common during treatment
- Other GI effects include nausea, vomiting, and abdominal pain
- Monitor for dehydration, and if necessary, do not give the second dose
Embryofetal toxicity, carcinogenicity, and male infertility
- Based on findings from animal reproduction studies, may cause fetal harm when administered to pregnant females
- Considered a potential human carcinogen; mammary adenocarcinomas and squamous cell carcinomas occurred in rats at systemic exposures less than the expected human exposure based on the recommended dose
- Based on testicular toxicity in animal studies, may irreversibly impair fertility in males of reproductive potential
Drug interaction overview
-
Cidofovir
- Do not coadminister with IV cidofovir
- Brincidofovir, a lipid-linked derivative of cidofovir, is intracellularly converted to cidofovir
-
OATP 1B1 and 1B3 inhibitors
- If possible, consider alternant medications that are not OATP1B1 or 1B3 inhibitors
- If concomitant use is necessary, increase monitoring for adverse reactions associated with brincidofovir (elevations in transaminases and bilirubin, diarrhea, or other GI adverse events) and postpone dosing of OATP1B1 or 1B3 inhibitors for at least 3 hr after brincidofovir administration
-
Vaccines
- No vaccine-drug interaction studies have been performed in humans; clinical impacts unknown
- Animal studies suggest coadministration of brincidofovir at the same time as live smallpox vaccine (vaccinia virus) may reduce the immune response to the vaccine
- Brincidofovir may reduce immune response to replication-defective smallpox vaccine (modified vaccinia virus Ankara)
Pregnancy & Lactation
Pregnancy
Based on findings from animal reproduction studies, may cause fetal harm when administered to pregnant females
Perform pregnancy testing in individuals of childbearing potential before initiating
Animal studies
- Administration to pregnant rats and rabbits during organogenesis resulted in embryotoxicity and structural malformations
- These effects occurred in animals at systemic exposures less than the expected human exposure based on the recommended dose
Contraception
- Females of childbearing potential: Use effective contraception during treatment and for at least 2 months after the last dose
- Males: Advise sexually active individuals with partners of childbearing potential to use condoms during treatment and for at least 4 months after last dose
Male infertility
- Based on testicular toxicity in animal studies, may irreversibly impair fertility in males of reproductive potential
Lactation
- Breastfeeding is not recommended in patients with smallpox
- Data are not available on the presence in human milk, effects on breastfed infants, or on milk production
- Brincidofovir is present in animal milk
Animal studies
- When administered to lactating rats (4 mg/kg/day or 15 mg/kg twice weekly), brincidofovir was detected in milk, but not in the plasma of nursing pups
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Prodrug; brincidofovir effectively penetrates cells via its lipid conjugate, releasing the nucleotide analog cidofovir, which then acts to inhibit viral replication
Cidofovir diphosphate selectively inhibits orthopoxvirus DNA polymerase-mediated viral DNA synthesis; incorporation of cidofovir into the growing viral DNA chain results in reductions in the rate of viral DNA synthesis
Absorption
Bioavailability: 16.8% (oral suspension); 13.4% (tablet)
Peak plasma time: 3 hr (brincidofovir); 47 hr (cidofovir diphosphate)
Peak plasma concentration: 480 ng/mL (brincidofovir); 9.7 pg/106 cells (cidofovir diphosphate)
AUC: 3400 ng⋅hr/mL(brincidofovir); 1200 pg⋅hr/106 cells (cidofovir diphosphate)
Effect of food
- AUC decreased by 31%
- Peak plasma concentration decreased by 49%
Distribution
Protein bound: >99.9%
Vd: 1230 L
Blood/plasma ratio: 0.48-0.61
Metabolism
Brincidofovir is a prodrug that is converted intracellularly to cidofovir, which is subsequently phosphorylated to cidofovir diphosphate, the active antiviral moiety, following oral administration
Metabolic pathways: Hydrolysis, CYP4F2
Elimination
Half-life: 19.3 hr (brincidofovir); 113 hr (cidofovir diphosphate)
Clearance: 44.1 L/hr
Excretion: 51% (as metabolites) in urine; 40% (as metabolites) in feces
Administration
Preparation
Suspected carcinogen: Avoid direct contact with broken or crushed tablets or oral suspension; if contact with skin or mucous membranes occurs, wash thoroughly with soap and water, and rinse eyes thoroughly with water
Oral Administration
Tablets
- May take on an empty stomach or with a low-fat meal (~400 calories, with ~25% of calories from fat)
- Swallow tablets whole; do not crush or divide
Suspension
- Take on an empty stomach
- Shake oral suspension before use
- Use an appropriate oral dosing syringe to correctly measure the total prescribed dose
- Discard unused portion after completion of 2 prescribed doses
-
Administration via enteral tube
- Draw up prescribed dose with calibrated catheter-tip syringe, and use this syringe to administer dose via the enteral tube
- Refill catheter-tip syringe with 3 mL of water, shake, and administer the contents via the enteral tube
- Flush with water before and after enteral administration
Storage
Store at 20-25ºC (68-77ºF); excursions permitted from 15-30ºC (59-86ºF)
Do not freeze
Handling
- Avoid direct contact with oral suspension
- If contact with skin or mucous membranes occurs, wash thoroughly with soap and water, and rinse eyes thoroughly with water
Images
Formulary
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