Bosentan: Uses, Interactions and Safety
Uses
Bosentan blocks endothelin receptors, helping relax the blood vessels in the lungs. It is used for selected forms of pulmonary arterial hypertension (PAH). European and Turkish product information also describe prevention of new finger or toe ulcers in systemic sclerosis with ongoing ulcer disease; this does not mean that existing ulcers will heal.
Administration
Tablets are taken by mouth under specialist supervision, with or without food. Film-coated and dispersible tablets have different instructions. Do not change the dose, switch formulations, or stop treatment without a plan from the PAH team. Treatment response and worsening breathlessness require review.
Safety
Liver injury, reduced haemoglobin and fluid retention are important risks. Liver enzymes must be checked before treatment and monthly thereafter. Blood counts are also monitored. Report jaundice, dark urine, unusual tiredness, rapid weight gain or worsening swelling promptly. Certain liver disorders and ciclosporin treatment prevent use.
Interactions
Bosentan can reduce the effectiveness of hormonal contraception and several other medicines. Ciclosporin must not be combined; fluconazole, rifampicin and tacrolimus require particular review. Warfarin may need closer INR monitoring. Sildenafil and tadalafil can be used in specialist PAH regimens, but blood concentrations change and the combination must be assessed. Paxlovid requires a specific prescriber-managed interruption plan.
Pregnancy and breastfeeding
Pregnancy is contraindicated because of fetal risk. Reliable contraception and pregnancy testing are essential; hormone-based contraception alone is insufficient. Contact the specialist immediately if pregnancy is suspected. Breastfeeding is not recommended during treatment.
Adverse effects
Common problems include headache, ankle swelling, anaemia and abnormal liver tests. These effects are not interchangeable with PAH progression: new symptoms should be assessed rather than attributed automatically to the medicine.
Sources
- Tracleer Summary of Product Characteristics
- TRACLEER 62,5 mg Turkish product information
- Tracleer US Prescribing Information
- Paxlovid US Prescribing Information
Additional verified references
The linked Turkish profile contains the medicine record and its documented interaction list.