Volibris Dosage/Direction for Use

Treatment must be initiated by a physician experienced in the treatment of PAH.
Posology: Ambrisentan monotherapy: Volibris is to be taken orally to begin at a dose of 5 mg once daily and may be increased to 10 mg daily depending upon clinical response and tolerability.
Ambrisentan in combination with tadalafil: When used in combination with tadalafil, Volibris should be titrated to 10 mg once daily.
In the AMBITION study, patients received 5 mg ambrisentan daily for the first 8 weeks before up titrating to 10 mg, dependent on tolerability (see Pharmacology: Pharmacodynamics under Actions). When used in combination with tadalafil, patients were initiated with 5 mg ambrisentan and 20 mg tadalafil. Dependent on tolerability the dose of tadalafil was increased to 40 mg after 4 weeks and the dose of ambrisentan was increased to 10 mg after 8 weeks. More than 90% of patients achieved this. Doses could also be decreased depending on tolerability.
Limited data suggest that the abrupt discontinuation of ambrisentan is not associated with rebound worsening of PAH.
When co-administered with cyclosporine A, the dose of ambrisentan should be limited to 5 mg once daily and the patient should be carefully monitored (see Pharmacology: Pharmacokinetics under Actions and Interactions).
Special populations: Elderly patients: No dose adjustment is required in patients over the age of 65 (see Pharmacology: Pharmacokinetics under Actions).
Patients with renal impairment: No dose adjustment is required in patients with renal impairment (see Pharmacology: Pharmacokinetics under Actions). There is limited experience with ambrisentan in individuals with severe renal impairment (creatinine clearance <30 ml/min); therapy should be initiated cautiously in this subgroup and particular care taken if the dose is increased to 10 mg ambrisentan.
Patients with hepatic impairment: Ambrisentan has not been studied in individuals with hepatic impairment (with or without cirrhosis). Since the main routes of metabolism of ambrisentan are glucuronidation and oxidation with subsequent elimination in the bile, hepatic impairment might be expected to increase exposure (C_max and AUC) to ambrisentan. Therefore ambrisentan must not be initiated in patients with severe hepatic impairment, or clinically significant elevated hepatic aminotransferases (greater than 3 times the Upper Limit of Normal (>3xULN); see Contraindications and Precautions).
Paediatric population: The safety and efficacy of ambrisentan in children and adolescents aged below 18 years has not been established. No data are available (see Pharmacology: Toxicology: Preclinical safety data under Actions regarding data available in juvenile animals).
Method of administration: It is recommended that the tablet is swallowed whole and it can be taken with or without food. It is recommended that the tablet should not be split, crushed or chewed.