Ambrisentan


Concise Prescribing Info
Indications/Uses
Pulmonary arterial hypertension (WHO Class II/III).
Dosage/Direction for Use
Adult : PO Initial: 5 mg once daily, may increase up to 10 mg once daily.
Dosage Details
Oral
Pulmonary arterial hypertension
Adult: In patients w/ WHO functional class II and III PAH (idiopathic, heritable, or associated w/ connective tissue diseases): Initially, 5 mg once daily, may be increased up to 10 mg once daily if necessary.
Special Patient Group
Patients taking ciclosporin: Max: 5 mg once daily.
Hepatic Impairment
Severe: Contraindicated.
Administration
May be taken with or without food. Swallow whole, do not split/chew/crush.
Contraindications
Idiopathic pulmonary fibrosis. Severe hepatic impairment or clinically significant elevated hepatic aminotransferases (>3 times the upper limit of normal). Pregnancy and lactation.
Special Precautions
Patient w/ pulmonary veno-occlusive disease, significant anaemia. Severe renal (CrCl <30 ml/min) and moderate hepatic impairment. Patients taking concomitant ciclosporin.
Adverse Reactions
Significant: Autoimmune hepatitis (e.g. exacerbation of underlying autoimmune hepatitis, hepatic injury, hepatic enzyme elevations), reduced Hb and haematocrit, fluid retention, peripheral oedema, acute pulmonary oedema, decreased sperm count.
Nervous: Headache, dizziness, fatigue, asthenia.
CV: Palpitation, cardiac failure, flushing, hypotension, syncope, chest pain.
GI: Diarrhoea, vomiting, nausea, abdominal pain, constipation.
Resp: Dyspnoea, nasopharyngitis, nasal congestion, epistaxis, sinusitis, rhinitis.
Patient Counseling Information
This drug may cause dizziness, asthenia, hypotension, or fatigue, if affected, do not drive or operate machinery.
MonitoringParameters
Monitor for signs of hepatic injury, significant peripheral oedema. Monitor ALT and AST, Hb and haematocrit levels. Obtain mthly pregnancy test during treatment.
Overdosage
Symptoms: Headache, dizziness, flushing, nausea, nasal congestion, and potential hypotension. Management: In case of hypotension, give active CV support.
Drug Interactions
Increased exposure w/ ciclosporin. Rifampicin may cause transient increase in ambrisentan exposure.
Action
Description: Ambrisentan, an endothelin antagonist, is selective on endothelin type A (ETA) receptor. Endothelin is a potent vasoconstrictor which plays a pathogenic role in pulmonary arterial hypertension (PAH). Blockade of endothelin receptor leads to vasodilation and inhibition of smooth muscle proliferation.
Pharmacokinetics:
Absorption: Absorbed rapidly from the GI tract. Time to peak plasma concentration: Approx 2 hr.
Distribution: Plasma protein binding: 99%, mainly to albumin and to a lesser extent to α1-acid glycoprotein.
Metabolism: Metabolised via glucuronidation by several uridine diphosphate glucuronosyltransferase (UGT) isoenzymes to ambrisentan glucuronide and via oxidation, mainly by CYP3A4 and to a lesser extent by CYP3A5 and CYP2C19, to form 4-hydroxymethyl ambrisentan.
Excretion: Mainly via bile; urine (22%, 3.3% as unchanged drug). Terminal elimination half-life: Approx 15 hr.
Chemical Structure

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Storage
Store between 15-30°C.
Wear gloves during receiving, unpacking, and placing in storage.
ATC Classification
C02KX02 - ambrisentan ; Belongs to the class of other antihypertensives. Used in the treatment of pulmonary arterial hypertension.
Disclaimer: This information is independently developed by MIMS based on Ambrisentan from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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