Tecovirimat

Tecovirimat is a prescription medication used for the treatment of human smallpox disease. 

• Tecovirimat is available under the following different brand names: TPOXX

Common side effects of Tecovirimat include:

• headache,
• nausea,
• abdominal pain, and
• vomiting

Serious side effects of Tecovirimat include:

• hives,
• difficulty breathing, and
• swelling of the face, lips, tongue, or throat

Rare side effects of Tecovirimat include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
• Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; sudden dizziness, lightheartedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

 Adult and pediatric dosage

Capsule

• 200mg

Injection, lyophilized powder for reconstitution

• 200mg/20mL

Human Smallpox Disease

• Adult dosage
• Oral
  • 40 kg to less than 120 kg: 600 mg orally twice daily for 14 days
  • Above 120 kg: 600 mg orally thrice daily for 14 days
  • Take within 30 minutes after eating a full meal
• IV
  • Use if patients are unable to take orally
  • If IV treatment is necessary, switch to capsules to complete 14-day treatment as soon as oral therapy can be tolerated
  • In patients receiving an IV infusion, give the first oral dose at the next scheduled IV dosing
  • 35 kg to less than 120 kg: 200 mg IV over 6 hours every 12 hours for 14 days
  • Above 120 kg: 300 mg IV over 6 hours every 12 hours for 14 days

Pediatric dosage

• Oral
  • Below 13 kg: Safety and efficacy not established
  • 13 kg to 24 kg: 200 mg orally twice daily for 14 days
  • 25 kg to 39  kg: 400 mg orally twice daily for 14 days
  • 40 kg to less than 120 kg: 600 mg orally twice daily for 14 days
  • More than 120 kg: 600 mg orally thrice daily for 14 days
  • Take within 30 minutes after eating a full meal
• IV
  • Below 3 kg: Safety and efficacy not established
  • 3 kg to 34 kg: 6 mg/kg IV over 6 hours every 12 hours for 14 days; patients weighing above 13 kg should switch to capsules to complete 14-day treatment as soon as oral therapy can be tolerated
  • 35 kg to less than 120 kg: 200 mg IV over 6 hours every 12 hours for 14 days
  • Above 120 kg: 300 mg IV over 6 hours every 12 hours for 14 days

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first

• Tecovirimat has severe interactions with no other drugs.
• Tecovirimat has serious interactions with the following drug:
  • pacritinib
• Tecovirimat has moderate interactions with 302 other drugs.
• Tecovirimat has minor interactions with no other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions or concerns.

Contraindications

• Capsules: None
• Injection: Severe renal impairment (CrCl less than 30 mL/min)

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Tecovirimat?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Tecovirimat?”

Cautions

• 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 (see Drug interaction overview)
• Risks of hydroxypropyl-β-cyclodextrin excipient for patients with renal insufficiency and pediatric patients less than 2 years
• In healthy patients and patients with mild to severe renal insufficiency, most of an 8-g dose of hydroxypropyl-β-cyclodextrin (per 200 mg tecovirimat/20 mL solution) is eliminated in urine
• It is known that clearance of hydroxypropyl-β-cyclodextrin is reduced in patients with mild, moderate, and severe renal impairment, resulting in higher exposure to hydroxypropyl-β-cyclodextrin
• In pediatric patients less than 2 years of age, limited data are available on the use of hydroxypropyl-β-cyclodextrin; there is potential for drug accumulation due to renal immaturity in these patients, and monitoring of renal function after treatment is recommended
• Monitor closely CrCl
• If renal toxicity is suspected, consider oral administration if possible or to using an alternative medication
• IV route is contraindicated in patients with severe renal impairment (CrCl less than 30 mL/min)

Drug interaction overview

• Weak inducer of CYP3A4 and a weak inhibitor of CYP2C8 and CYP2C19; however, the effects are not expected to be clinically relevant for most substrates of those enzymes
• UGT enzymes: Substrate of UGT1A1 and UGT1A4
• Transporter systems: Inhibits BCRP in vitro
• Monitor sensitive CYP3A4 substrates (e.g., midazolam) for decreased effectiveness
• Monitor sensitive CYP2C8 (e.g., repaglinide) and CYP2C19 substrates for increased effect
• Vaccines
  • No vaccine-drug interaction studies have been performed on humans
  • 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
  • The clinical impact of this interaction on vaccine efficacy is unknown

Pregnancy & Lactation

• There are no available data regarding use in pregnant women

Infertility

• 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

Lactation

• 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