ambrisentan: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
ambrisentan: clinical details
Prescribing considerations
- Initiation and ongoing review should be led by a PAH-experienced specialist.
- Establish PAH classification, functional class and evidence of fluid overload before treatment.
- Evidence is insufficient to establish the benefit–risk balance in functional class I; monotherapy efficacy is not established in functional class IV.
- Use cautiously in severe renal impairment.
- Consider possible effects on spermatogenesis when discussing fertility with male patients.
Contraindications and cautions
- Pregnancy or breastfeeding
- Potential for pregnancy without reliable contraception
- Hypersensitivity to ambrisentan or an excipient
- Severe hepatic impairment, with or without cirrhosis
- Baseline ALT or AST above three times the upper limit of normal
- Idiopathic pulmonary fibrosis, with or without secondary pulmonary hypertension
Monitoring
- Check ALT and AST before initiation and monthly thereafter; assess promptly for symptoms of hepatic injury.
- Check haemoglobin or haematocrit during treatment, including early after initiation and periodically thereafter.
- Monitor for clinically significant fluid retention, weight gain and decompensated heart failure.
- For patients who could become pregnant, document a negative pretreatment test, reliable contraception and ongoing pregnancy testing.
- Acute pulmonary oedema should prompt assessment for pulmonary veno-occlusive disease.
Clinical pharmacology
Ambrisentan is an orally active, highly selective endothelin A receptor antagonist. It is absorbed rapidly, is highly protein bound, and is cleared mainly through glucuronidation and oxidative metabolism followed by biliary elimination.
Formulation and product differences
- The selected product is a pink, oval, film-coated tablet that should not be split, crushed or chewed.
- It contains lactose and is essentially sodium-free.
- Tablet appearance, scoring and excipients can differ between ambrisentan products; check the specific product information before substitution or manipulation.
ambrisentan preparations and strengths
Tablet
Route: Oral
Strengths: 2.5 mg, 5 mg, 10 mg
ambrisentan interactions
Tell the PAH team about all prescribed, non-prescription and herbal products. Important examples include:
Cyclosporine A
It substantially increases ambrisentan exposure, requiring specialist adjustment and monitoring.
Rifampicin
It can temporarily increase ambrisentan exposure when started, so close monitoring is advised.
Other targeted PAH treatments
Some combinations are established, but evidence for certain vasodilator combinations is limited and specialist oversight is required.
Hormonal contraceptives
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.