Standard Bosentan Dosage
Bosentan (Tracleer) treats pulmonary arterial hypertension (PAH). The usual starting dose for adults is 62.5 mg twice daily for 4 weeks, then 125 mg or 250 mg twice daily based on tolerability and weight. It's taken orally with or without food.[1]
Dosage in Mild Liver Impairment (Child-Pugh A)
No dose adjustment needed. Use standard dosing: start at 62.5 mg twice daily, titrate to 125 mg twice daily.[1][2]
Dosage in Moderate Liver Impairment (Child-Pugh B)
Avoid use. Bosentan is contraindicated due to risk of liver injury and elevated transaminases.[1][2]
Dosage in Severe Liver Impairment (Child-Pugh C)
Avoid use. Contraindicated; higher risk of hepatotoxicity.[1][2]
Monitoring and Adjustments
Check liver enzymes (ALT/AST) before starting, monthly for first 3 months, then every 3 months. Discontinue if ALT/AST >8x upper limit of normal or >5x with symptoms/bilirubin >2x upper limit. Reduce dose by 50% if mild elevation (3-5x upper limit).[1]
Why Liver Impairment Matters
Bosentan is metabolized by CYP3A4 in the liver, with biliary excretion. Impairment raises drug levels, increasing hepatotoxicity risk. Label warns against use in moderate/severe cases.[1][2]
[1]: Tracleer Prescribing Information (FDA)
[2]: DrugPatentWatch.com - Bosentan