In pulmonary hypertension, patients over 12 years of age may be given bosentan orally in an initial dose of 62.5 mg twice daily, increased after 4 weeks to a maintenance dose of 125 mg twice daily. In those with low body weight (below 40 kg) both the initial and maintenance doses are 62.5 mg twice daily. In systemic sclerosis with ongoing digital ulcer disease, bosentan is given in the same doses as for pulmonary hypertension; there are no data on safety or efficacy in patients under 18 years of age. Or as prescribed by the physician.