Tembexa Side Effects Center

Last updated on RxList: 8/11/2021
Tembexa Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

What Is Tembexa?

Tembexa (brincidofovir) is an orthopoxvirus nucleotide analog DNA polymerase inhibitor and is used to treat human smallpox disease in adult and pediatric patients, including neonates.

What Are Side Effects of Tembexa?

Side effects of Tembexa include:

  • diarrhea,
  • nausea,
  • vomiting, and
  • abdominal pain.

Dosage for Tembexa

The dose of Tembexa for adult and pediatric patients weighing 48 kg or above is 200mg (two 100mg tablets or 20mL oral suspension for patients who cannot swallow tablets) once weekly for 2 doses. The dose of Tembexa for adult and pediatric patients weighing 10 kg to less than 48 kg is 4mg/kg oral suspension once weekly for 2 doses. The dose of Tembexa for pediatric patients weighing less than 10 kg is 6 mg/kg oral suspension once weekly for 2 doses.


Tembexa In Children

As in adults, the effectiveness of Tembexa in smallpox infected pediatric patients, including neonates, is based solely on efficacy studies in animal models of orthopoxvirus disease. The recommended pediatric dosing regimen is expected to produce brincidofovir exposures that are comparable to those in adults based on a population pharmacokinetic modeling and simulation approach. The dosage for pediatric patients is based on weight.

What Drugs, Substances, or Supplements Interact with Tembexa?
 

Tembexa may interact with other medicines such as:

OATP1B1 or 1B3 inhibitors (e.g., clarithromycin, cyclosporine, erythromycin, gemfibrozil, HIV and hepatitis C virus protease inhibitors, and rifampin).

Tell your doctor all medications and supplements you use.


Tembexa During Pregnancy and Breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant before using Tembexa; it may harm a fetus. Pregnancy testing is recommended in females of childbearing potential before initiation of Tembexa. Females of childbearing potential are advised to use effective contraception during treatment and for at least 2 months after the last dose of Tembexa. Males with partners of childbearing potential are advised to use condoms during treatment and for at least 4 months after the last dose of Tembexa. It is unknown if Tembexa passes into breast milk, however, because of the potential for variola virus transmission through direct contact with the breastfed infant, breastfeeding is not recommended in patients with smallpox.

Additional Information

Our Tembexa (brincidofovir) Tablets, for Oral Use and Tembexa (brincidofovir) Oral Suspension Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

SLIDESHOW

Fungal Skin Infections: Types, Symptoms, and Treatments See Slideshow
Tembexa Professional Information

SIDE EFFECTS

The following clinically significant adverse reactions are described elsewhere in the labeling:

  • Elevations in hepatic transaminases and bilirubin [see WARNINGS AND PRECAUTIONS]
  • Diarrhea and other GI adverse events [see WARNINGS AND PRECAUTIONS]

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The safety of TEMBEXA has not been studied in patients with smallpox disease.

The safety of TEMBEXA was evaluated in 392 adult subjects aged 18 to 77 years in Phase 2 and 3 randomized, placebo-controlled clinical trials. Of the subjects who received a 200 mg total weekly dose of TEMBEXA, 54% were male, 85% were White, 7% were Black/African American, 6% were Asian, and 10% were Hispanic or Latino. Twenty-one percent of subjects in the studies were age 65 or older. Of these 392 subjects, 85% received a 200 mg total weekly dose of TEMBEXA for at least 2 weeks.

Common Adverse Reactions

The most common adverse reactions (adverse events assessed as causally related by the investigator) experienced in the first 2 weeks of dosing with TEMBEXA were diarrhea and nausea. Adverse reactions that occurred in at least 2% of subjects in the TEMBEXA treatment group are shown in Table 2.

Table 2: Adverse Reactions (All Grades) Reported in ≥2% of Subjects

Adverse Reaction TEMBEXA 200 mg
N=392
%
Placebo
N=208
%
Diarrheaa 8 3
Nausea 5 1
Vomitingb 4 1
Abdominal painc 3 2
Note: Only adverse reactions with onset in the first 2 weeks of treatment are presented.
a.Composite term includes: bowel movement irregularity, defecation urgency, diarrhea, fecal incontinence, and frequent bowel movements.
b.Composite term includes: vomiting and retching.
c.Composite term includes: abdominal discomfort, abdominal distention, abdominal pain, abdominal pain lower, abdominal pain upper, abdominal tenderness, and gastrointestinal pain.

Adverse Reactions Leading To Discontinuation Of TEMBEXA

Fifteen subjects (4%) had their treatment with TEMBEXA discontinued due to adverse reactions. One subject had two adverse reactions; the other subjects had one reaction each. These adverse reactions were:

  • Diarrhea (n=9)
  • Nausea (n=3)
  • Vomiting (n=1)
  • Enteritis (n=1)
  • ALT increased (n=1)
  • Dyspepsia (n=1)

These adverse reactions were mild (Grade 1, n=1), moderate (Grade 2, n=7) or severe (Grade 3, n=8) in severity and resolved upon discontinuation of TEMBEXA.

Less Common Adverse Reactions

Clinically significant adverse reactions that were reported in <2% of subjects (and also occurred in 2 or more subjects) exposed to TEMBEXA and at rates higher than in subjects who received placebo are listed below:

  • 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 (includes rash, maculo-papular rash, pruritic rash)

Selected treatment-emergent laboratory values occurring during the first 2 weeks of treatment with TEMBEXA are presented in Table 3

Table 3: Frequencies of Selected Laboratory Abnormalities

Laboratory Parameter Abnormalitya TEMBEXA 200 mg
N=392
Placebo
N=208
Alanine aminotransferase (ALT)b n 382 203
Grade 2 (>3 to 5x ULN), (%) 3 2
Grade 3 (>5 to 20x ULN), (%) 2 1
Grade 4 (>20x ULN), (%) 0 0
Aspartate aminotransferase (AST)c n 380 201
Grade 2 (>3 to 5x ULN), (%) 2 1
Grade 3 (>5 to 20x ULN), (%) 1 0
Grade 4 (>20x ULN), (%) 0 0
Total bilirubin n 382 203
Grade 2 (>1.5 to 3x ULN), (%) 3 2
Grade 3 (>3 to 10x ULN), (%) 1 <1
Grade 4 (>10x ULN), (%) 0 <1
Serum creatinine n 383 205
Grade 2 (>1.5 to 3x ULN), (%) 4 4
Grade 2 (>1.5 to 3x ULN), (%) <1 0
Grade 2 (>1.5 to 3x ULN), (%) 0 0
ULN = upper limit of normal
a. Frequencies are based on treatment-emergent laboratory abnormalities. Graded per Common Terminology Criteria for Adverse Events (CTCAE) version 4.03 toxicity grading criteria.
b. ALT >10x ULN occurred in one subject in the TEMBEXA group and no subjects in the placebo group. c. No subjects reported AST >10x ULN.

Adverse Reactions In Pediatric Subjects

In 23 pediatric subjects aged 7 months to 17 years who received TEMBEXA in a randomized, placebo-controlled clinical trial, the adverse reactions and laboratory abnormalities observed with TEMBEXA were similar to adults [see Use In Specific Populations].

DRUG INTERACTIONS

Effect Of Other Drugs On TEMBEXA

Inhibitors For Organic Anion Transporting Polypeptide (OATP) 1B1 And 1B3

Concomitant use of TEMBEXA with OATP1B1 and 1B3 inhibitors (clarithromycin, cyclosporine, erythromycin, gemfibrozil, human immunodeficiency virus [HIV] and hepatitis C virus [HCV] protease inhibitors, rifampin [single dose]) increase brincidofovir AUC and Cmax which may increase TEMBEXA-associated adverse reactions [see CLINICAL PHARMACOLOGY].

Where possible, consider alternative medications that are not OATP1B1 or 1B3 inhibitors. If concomitant use with TEMBEXA is necessary, increase monitoring for adverse reactions associated with TEMBEXA (elevations in transaminases and bilirubin, diarrhea, or other GI adverse events) [see WARNINGS AND PRECAUTIONS] and postpone the dosing of OATP1B1 or 1B3 inhibitors for at least 3 hours after TEMBEXA administration.

Vaccine Interactions

No vaccine-drug interaction studies have been performed in human subjects. Animal studies have indicated that coadministration of TEMBEXA at the same time as live smallpox vaccine (vaccinia virus) may reduce the immune response to the vaccine. It is also possible that TEMBEXA may reduce the immune response to replication-defective smallpox vaccine (modified vaccinia virus Ankara). The clinical impacts of these potential interactions on vaccine efficacy are unknown.

Read the entire FDA prescribing information for Tembexa (Brincidofovir Tablets)

QUESTION

Bowel regularity means a bowel movement every day. See Answer

© Tembexa Patient Information is supplied by Cerner Multum, Inc. and Tembexa Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

Health Solutions From Our Sponsors