Skip to Content

Bosentan Side Effects

In Summary

Commonly reported side effects of bosentan include: increased serum alanine aminotransferase and increased serum aspartate aminotransferase. Other side effects include: decreased hematocrit, decreased hemoglobin, hepatic insufficiency, hypotension, palpitations, and flushing. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to bosentan: oral tablet

In addition to its needed effects, some unwanted effects may be caused by bosentan. In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking bosentan:

More common:
  • Blurred vision
  • confusion
  • dizziness
  • dark urine
  • faintness or lightheadedness when getting up from a lying or sitting position
  • fever with or without chills
  • light-colored stools
  • loss of appetite
  • nausea and vomiting
  • stomach pain
  • sudden sweating
  • unusual tiredness or weakness
  • yellow eyes or skin
Less common:
  • Swelling
Incidence not known:
  • Black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • blue lips and fingernails
  • chest pain
  • chills
  • clay-colored stools
  • coughing that sometimes produces a pink frothy sputum
  • coughing up blood
  • dark urine
  • decrease in the amount of urine
  • difficult, fast, or noisy breathing, sometimes with wheezing
  • fainting
  • fast heartbeat
  • fatigue on exertion
  • fever
  • headache
  • hives
  • hoarseness
  • increased sweating
  • irritation
  • itching
  • joint pain, stiffness, or swelling
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • noisy, rattling breathing
  • pale skin
  • pinpoint red spots on the skin
  • rash
  • redness of the skin
  • shortness of breath
  • swelling of the eyelids, face, lips, hands, fingers, legs, ankles, or feet
  • tightness in the chest
  • troubled breathing at rest
  • troubled breathing or swallowing
  • troubled breathing with exertion
  • unpleasant breath odor
  • unusual bleeding or bruising
  • vomiting of blood
  • weight gain
  • wheezing

If any of the following symptoms of overdose occur while taking bosentan, get emergency help immediately:

Symptoms of overdose:
  • Increased heart rate

Minor Side Effects

Some of the side effects that can occur with bosentan may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Fast, irregular, pounding, or racing heartbeat or pulse
  • feeling of warmth
  • muscle aches
  • redness of the face, neck, arms, and occasionally upper chest
  • sore throat
  • stuffy or runny nose
Less common:
  • Acid or sour stomach
  • belching
  • heartburn
  • indigestion
  • stomach discomfort, upset, or pain

For Healthcare Professionals

Applies to bosentan: oral tablet


Hepatic side effects including elevations in aminotransferases (ALT/AST) have been reported. Bosentan has resulted in at least 3-fold upper limit of normal elevation of liver aminotransferases (ALT/AST) in approximately 11% of treated patients accompanied by elevated bilirubin in small number of cases. Serum aminotransferases must be measured prior to initiating therapy and monthly thereafter. Due to the potential for serious liver injury, bosentan should be avoided in patients with moderate or severe liver impairment. In addition, it should generally be avoided in patients with elevated aminotransferases (more than 3 times the upper limit of normal) since monitoring liver injury in such patients may be more difficult.

Rare cases of liver failure have been reported during postmarketing.[Ref]

Elevations of AST and/or ALT associated with bosentan are dose-dependent and can occur both early and late in treatment. The elevations generally progress slowly and are typically asymptomatic. Elevations are usually reversible after treatment, interruption or cessation. In addition, the aminotransferase observations may reverse spontaneously while continuing treatment with bosentan.

If aminotransferase elevations are accompanied by clinical symptoms of liver injury (e.g., nausea, vomiting, fever, abdominal pain, jaundice, lethargy, fatigue) or increases in bilirubin are >= 2 times the upper limit of normal, treatment should be stopped.

Postmarketing studies have reported rare cases of unexplained hepatic cirrhosis after prolonged therapy (greater than 12 months) with bosentan in patients with multiple comorbidities and drug therapies. In at least one case, the initial presentation (after more than 20 months of treatment) included pronounced elevations in aminotransferases and bilirubin levels accompanied by nonspecific symptoms, all of which resolved slowly over time after discontinuation of bosentan. This reinforces the importance of strict adherence to the monthly monitoring schedule for the duration of treatment and the treatment algorithm, which includes stopping bosentan with a rise of aminotransferases accompanied by signs or symptoms of liver dysfunction. Elevations in aminotransferases require close attention.[Ref]


Hematologic side effects including dose-related decreases in hematocrit and hemoglobin have been observed in patients treated with bosentan. Hemoglobin levels should be monitored after 1 and 3 months of treatment and then every 3 months. If a marked decrease in hemoglobin concentration occurs, further examination should be undertaken to determine the cause and need for specific treatment. Thrombocytopenia has been reported in postmarketing studies.[Ref]


General side effects including flushing (9%), lower limb edema (8%), edema (4%), and fatigue (4%) have been reported.[Ref]


Cardiovascular side effects including hypotension (7%) and palpitations (5%) have been reported. At least one case of leukocytoclastic vasculitis has been reported. In addition, data from a placebo-controlled trial of patients with severe chronic heart failure treated with bosentan showed an increased incidence of hospitalization for CHF associated with weight gain and increased leg edema during the first 4 to 8 weeks of therapy. There have also been numerous postmarketing reports of fluid retention in patients with pulmonary hypertension occurring within weeks after starting bosentan. In addition, the possibility of associated pulmonary veno-occlusive disease should be considered if signs of pulmonary edema develop following bosentan administration. If this occurs, bosentan should be discontinued.[Ref]


Respiratory side effects including nasopharyngitis (11%) have been reported.[Ref]


Gastrointestinal side effects including diarrhea (9%) and dyspepsia (4%) have been reported.[Ref]


Hypersensitivity reactions including rash and angioneurotic edema have been reported in postmarketing studies.[Ref]


Dermatologic side effects have included pruritus (4%).

Nervous system

Nervous system side effects have included headache (14% to 22%) and dizziness (8%).[Ref]


Genitourinary side effects including reduced sperm counts have been reported.


1. Kenyon KW, Nappi JM "Bosentan for the treatment of pulmonary arterial hypertension." Ann Pharmacother 37 (2003): 1055-62

2. "Product Information. Tracleer (bosentan)." Acetelion Pharmaceuticals US, Inc, South San Francisco, CA.

3. Gasser S, Kuhn M, Speich R "Severe necrotising leucocytoclastic vasculitis in a patient taking bosentan." BMJ 329 (2004): 430

4. Korn JH, Mayes M, Matucci Cerinic M, et al. "Digital ulcers in systemic sclerosis: Prevention by treatment with bosentan, an oral endothelin receptor antagonist." Arthritis Rheum 50 (2004): 3985-93

5. Galie N, Beghetti M, Gatzoulis MA, et al. "Bosentan therapy in patients with eisenmenger syndrome: a multicenter, double-blind, randomized, placebo-controlled study." Circulation 114 (2006): 48-54

Not all side effects for bosentan may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.