Drug information of tecovirimat


Tecovirimat is used to treat human smallpox disease caused by the variola virus.

Mechanism of effect

Tecovirimat inhibits the activity of the orthopoxvirus VP37 protein and blocks its interaction with cellular Rab9 GTPase and TIP47, preventing formation of egress-competent enveloped virions (necessary for dissemination of virus).


Tecovirimat prevents viral spread throughout the body. This drug inhibits its molecular target, a protein called p37, from interacting with intracellular transport components necessary for the production of enveloped virus, and therefore the spread of virus .


Peak plasma time: 4-6 hr

Peak plasma concentration: 2106 ng/mL

Minimum plasma concentration: 587 ng/mL

AUC: 28,791 hr·ng/mL

Effect of food (meal: 600 kcal, 25 g fat) relative to fasting: AUC increase 39%

Protein bound: 77-82%

Vd: 1030 L

Metabolism:Metabolic pathways include hydrolysis, UGT1A1d, and UGT1A4

Half-life: 20 hr

Clearance: 31 L/hr

Excretion: 73% urine (predominantly as metabolites); 23% feces (predominantly as parent drug)

Drug indications

Smallpox: Treatment of human smallpox disease caused by variola virus in adults and pediatric patients weighing ≥13 kg.


<13 kg: Safety and efficacy not established

13 kg to <25 kg: 200 mg PO BID for 14 days

25 kg to <40 kg: 400 mg PO BID for 14 days

≥40 kg: 600 mg PO BID for 14 days

Drug contraindications


Side effects





Abdominal pain



Dry mouth, chapped lips, dyspepsia, eructation, oral paresthesia,Pyrexia, pain, chills, malaise, thirst,Abnormal electroencephalogram, hematocrit decreased, hemoglobin decreased, heart rate increased,Arthralgia, osteoarthritis,Migraine, disturbance in attention, dysgeusia, paresthesia,Depression, dysphoria, irritability, panic attack,Oropharyngeal pain,Palpable purpura, rash, pruritic rash, facial redness, facial swelling, pruritus,EEG change, abnormal,Mild upset stomach, moderate diarrhea, fever and chills.


Smallpox Vaccine Live


-Coadministration with repaglinide (an antidiabetic agent) may cause mild-to-moderate hypoglycemia; monitor blood glucose and monitor for hypoglycemic symptoms when administering tecovirimat with repaglinide.

-Some animal studies have indicated that coadministration of tecovirimat at the same time as live smallpox vaccine (vaccinia virus) may reduce the immune response to the vaccine.

-Tecovirimat is a weak inducer of CYP3A4 and a weak inhibitor of CYP2C8 and CYP2C19. Monitor sensitive CYP3A4 substrates (eg, midazolam) for decreased effectiveness And  sensitive CYP2C8 (eg, repaglinide) and CYP2C19 substrates for increased effect.

Points of recommendation

-Efficacy studied in animal models; effectiveness has not been determined in humans.

-Efficacy may be reduced in immunocompromised patients based on studies demonstrating reduced efficacy in immunocompromised animal models.

-Monitoring Parameters:Blood glucose, symptoms of hypoglycemia

Pregnancy level

No data are available regarding the effect on female and male reproductive potential in humans.

Decreased fertility due to testicular toxicity was observed in male mice.

Breast feeding warning

The development and health benefits of breastfeeding should be considered along with the mother’s clinical need for the drug and any potential adverse effects on the breastfed child or from the underlying maternal condition.

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