Pulmonary arterial hypertension (PAH)

Active Ingredient: Bosentan

Indication for Bosentan

Population group: only adults (18 years old or older)
Therapeutic intent: Curative procedure

Bosentan is indicated for the treatment of pulmonary arterial hypertension (PAH) to improve exercise capacity and symptoms in patients with WHO functional class III. Efficacy has been shown in:

  • Primary (idiopathic and heritable) PAH
  • PAH secondary to scleroderma without significant interstitial pulmonary disease
  • PAH associated with congenital systemic-to-pulmonary shunts and Eisenmenger’s physiology

Some improvements have also been shown in patients with PAH WHO functional class II.

For this indication, competent medicine agencies globally authorize below treatments:

62.5 mg twice daily for 4 weeks and thereafter 125 mg twice daily


Dosage regimens

Oral, 62.5 milligrams bosentan, 2 times daily, over the duration of 4 weeks. Afterwards, oral, 125 milligrams bosentan, 2 times daily.

Detailed description

In adult patients, bosentan treatment should be initiated at a dose of 62.5 mg twice daily for 4 weeks and then increased to the maintenance dose of 125 mg twice daily. The same recommendations apply to re-introduction of bosentan after treatment interruption.

Management in the event of clinical deterioration of PAH

In the event of clinical deterioration (e.g. decrease in 6-minute walk test distance by at least 10% compared with pre-treatment measurement) despite bosentan treatment for at least 8 weeks (target dose for at least 4 weeks), alternative therapies should be considered. However, some patients who show no response after 8 weeks of treatment with bosentan may respond favourably after an additional 4 to 8 weeks of treatment.

In the event of late clinical deterioration despite treatment with bosentan (i.e. after several months of treatment), the treatment should be re-assessed. Some patients not responding well to 125 mg twice daily of bosentan may slightly improve their exercise capacity when the dose is increased to 250 mg twice daily. A careful benefit/risk assessment should be made, taking into consideration that the liver toxicity is dose dependent.

Discontinuation of treatment

There is limited experience with abrupt discontinuation of bosentan in patients with PAH. No evidence for acute rebound has been observed. However, to avoid the possible occurrence of harmful clinical deterioration due to potential rebound effect, gradual dose reduction (halving the dose for 3 to 7 days) should be considered. Intensified monitoring is recommended during the discontinuation period. If the decision to withdraw bosentan is taken, it should be done gradually while an alternative therapy is introduced.

Dosage considerations

It should be taken orally morning and evening, with or without food.

Active ingredient


Bosentan is a dual endothelin receptor antagonist (ERA) with affinity for both endothelin A and B (ETA and ETB) receptors. Bosentan decreases both pulmonary and systemic vascular resistance resulting in increased cardiac output without increasing heart rate.

Read more about Bosentan

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