Fexinidazole Side Effects

Medically reviewed by Drugs.com. Last updated on May 18, 2025.

Applies to fexinidazole: oral tablet.

Precautions

It is very important that your doctor check your or your child's progress at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Do not take this medicine if you are also taking disulfiram within the last 2 weeks.

Call your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem, including QT prolongation.

Check with your doctor right away if you have change in personality or behavior, discouragement, feeling sad or empty, hallucinations, irritability, lack of appetite, loss of interest or pleasure, nightmares, thoughts of killing oneself, tiredness, trouble concentrating, or trouble sleeping. These could be symptoms of serious mental health problems.

This medicine lowers the number of some types of blood cells in your body. Because of this, you may get infections more easily. To help with these problems, avoid being near people who are sick or have infections. Wash your hands often.

Check with your doctor right away if you or your child have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

This medicine may cause some people to become dizzy, drowsy, or tired. Do not drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.

Serious side effects of fexinidazole

Along with its needed effects, fexinidazole may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking fexinidazole:

More common side effects

• black, tarry stools
• chest pain
• chills
• confusion
• cough
• fever
• lower back or side pain
• mood or mental changes
• muscle cramps in the hands, arms, feet, legs, or face
• numbness and tingling around the mouth, fingertips, or feet
• painful or difficult urination
• pale skin
• shakiness in the legs, arms, hands, or feet
• sore throat
• stomach pain or cramps
• swelling of the feet or lower legs
• trembling or shaking of the hands or feet
• trouble breathing
• trouble sleeping
• ulcers, sores, or white spots in the mouth
• unusual bleeding or bruising
• unusual tiredness or weakness

Less common side effects

• anxiety
• blurred vision
• deep or fast breathing with dizziness
• dizziness
• dry mouth
• fast, irregular, pounding, or racing heartbeat or pulse
• headache
• irritability
• nervousness
• numbness of the feet, hands, and around the mouth
• pounding in the ears
• restlessness
• shaking

Rare side effects

• change in personality
• changes in behavior
• discouragement
• feeling sad or empty
• lack of appetite
• loss of interest or pleasure
• seeing, hearing, or feeling things that are not there
• thoughts of killing oneself
• trouble concentrating

Incidence not known

• fainting
• nightmares

Other side effects of fexinidazole

Some side effects of fexinidazole may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

• acid or sour stomach
• back or neck pain
• belching
• feeling hot
• heartburn
• indigestion
• lack or loss of strength
• nausea
• stomach discomfort, upset, or pain
• vomiting

Less common side effects

• burning, crawling, itching, numbness, prickling, "pins and needles" , or tingling feelings
• burning feeling in the chest or stomach
• change in color vision
• constipation
• difficulty in speaking
• difficulty seeing at night
• drooling
• full or bloated feeling
• increased sensitivity of the eyes to sunlight
• increased sweating
• itching skin
• loss of balance control
• muscle spasm
• pressure in the stomach
• stiffness of the limbs
• swelling of the stomach area
• twisting movement of the body
• uncontrolled movement, especially of the face, neck, and back

See also:

For healthcare professionals

Applies to fexinidazole: oral tablet.

General adverse events

The most common side effects reported in human African trypanosomiasis patients treated with this drug in the comparative trial were headache, vomiting, insomnia, nausea, asthenia, tremor, decreased appetite, dizziness, hypocalcemia, dyspepsia, back pain, upper abdominal pain, and hyperkalemia.^[Ref]

Nervous system

• Very common (10% or more): Headache (up to 34.8%), tremor (up to 22%), dizziness (up to 18.9%)
• Common (1% to 10%): Extrapyramidal disorder, paresthesia^[Ref]

Gastrointestinal

• Very common (10% or more): Vomiting (up to 28.4%), nausea (up to 25.8%), dyspepsia (up to 12.9%), upper abdominal pain (up to 10.2%)
• Common (1% to 10%): Salivary hypersecretion, constipation, abdominal distension, gastritis^[Ref]

Psychiatric

• Very common (10% or more): Insomnia (up to 28%)
• Common (1% to 10%): Agitation, anxiety, abnormal behavior
• Frequency not reported: Hallucinations, psychotic disorder, depression, personality change, suicidal ideation, nightmares^[Ref]

Other

• Very common (10% or more): Asthenia (up to 22.7%)
• Common (1% to 10%): Feeling hot, chest pain, hot flush, gait disturbance^[Ref]

Metabolic

• Very common (10% or more): Decreased appetite (up to 21.2%), hypocalcemia (up to 13.6%)
• Common (1% to 10%): Hypoalbuminemia^[Ref]

Musculoskeletal

• Very common (10% or more): Back pain (up to 11.4%)
• Common (1% to 10%): Neck pain, muscle spasms^[Ref]

Hematologic

• Common (1% to 10%): Neutropenia^[Ref]

Neutropenia was defined as an absolute neutrophil count of less than 1000 cells/mm3 that occurred at any time after the first dose of study drug to the end of the study.^[Ref]

Cardiovascular

• Common (1% to 10%): Palpitations, hypertension
• Frequency not reported: QT interval prolonged^[Ref]

Respiratory

• Common (1% to 10%): Cough, dyspnea^[Ref]

Dermatologic

• Common (1% to 10%): Pruritus, hyperhidrosis^[Ref]

Ocular

• Common (1% to 10%): Photophobia^[Ref]

Hepatic

• Frequency not reported: Elevated liver transaminases^[Ref]

Further information

Fexinidazole side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer