Drug reference

Ambrisentan

Vasodilator · Antihypertensive

Also known as Volibris, LETAIRIS

VasodilatorAntihypertensive

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

7 major

SEVERE in our sources

PREGNANCY

Avoid (teratogenic in animal studies). Monthly pregnancy tests advised and effective contraception during treatment.

FDA category + note

Top interactionssee all 8 →

CyclosporineSevereDatabaseDDInter
LeflunomideSevereDatabaseDDInter
LomitapideSevereDatabaseDDInter
MipomersenSevereDatabaseDDInter

Mechanism

Endothelin-1 (ET-1) is a potent pulmonary vasoconstrictor produced in increased amounts in pulmonary arterial hypertension (PAH), which contracts vascular smooth muscle cells and causes proliferation primarily via ETA receptors. Ambrisentan is a selective ETA receptor antagonist, blocking the vasoconstrictive and proliferative effects of ET-1. This selective blockade may allow ETB receptors to continue stimulating the release of prostacyclin and nitric oxide, potentially offering a greater therapeutic effect.

Indications

Pulmonary arterial hypertension (initiated under specialist supervision)To improve exercise capacity in patients with WHO functional class II and III pulmonary arterial hypertensionmoderate PAH (functional class II–III)

Dosing

Adult: Initially 5 mg once daily by mouth, increased if necessary to 10 mg once daily. Manufacturer advises max dose 5 mg daily and close monitoring with concurrent use of ciclosporin.
Renal adjustment: Use with caution if eGFR less than 30 mL/minute/1.73 m2.
Hepatic adjustment: Avoid in severe impairment or if baseline serum transaminases exceed 3 times the upper limit of normal.
Max dose: 10 mg once daily (general); 5 mg once daily (with concurrent ciclosporin)

Pharmacokinetics

Half-life

9 h (at steady state)

Metabolism

Some metabolism by CYPs 3A4 and 2C19, followed by glucuronidation.

Contraindications

Pregnancy (teratogenic)
Significant anaemia
Pulmonary veno-occlusive disease
Severe hepatic impairment or baseline serum transaminases exceeding 3 times the upper limit of normal

Side effects

Common

Abdominal painAnaemiaAstheniaConstipationDiarrhoeaDizzinessEpistaxisFlushingHeadachesHypersensitivityIncreased risk of infectionNasal congestionNauseaPalpitationsSkin reactionsSyncopeTinnitusVision disordersVomitingPeripheral edemaAbnormal liver function testsheadachepulmonary edemaanemianasal congestion/pharyngitisedema

Serious