Bosentan


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Pulmonary HTN >12 yr <40 kg: Initial and maintenance: 62.5 mg bid; ≥40 kg: Initial: 62.5 mg bid for 4 wk. Maintenance: 125 mg bid.
Dosage Details
Oral
Pulmonary hypertension
Adult: >12 yr <40 kg: Initial and maintenance dose is 62.5 mg bid; ≥40 kg: Initially, 62.5 mg bid for 4 wk, then increased to a maintenance dose of 125 mg bid.
Elderly: No dosage adjustment needed.
Special Patient Group
Dosage adjustment for patients w/ confirmed LFT elevations. >3 and ≤5 x ULN: Reduce dose or discontinue therapy. Monitor LFT at least every 2 wk until LFT return to pre-treatment levels, continue or restart therapy as needed; >5 and ≤8 x ULN: Stop treatment and monitor LFT levels at least every 2 wk. Consider to restart therapy if LFT returns to pre-treatment levels; >8 x ULN: Stop treatment and bosentan should not be restarted.
Renal Impairment
No dosage adjustment needed in renal impairment or dialysis patients.
Hepatic Impairment
Mild: No dosage adjustment needed. Moderate and severe: Contraindicated.
Administration
May be taken with or without food.
Contraindications
Acute porphyria; moderate and severe hepatic impairment. Coadministration w/ ciclosporin or glibenclamide. Pregnancy (use 2 forms of contraception during treatment and 1 mth after stopping).
Special Precautions
Consider discontinuation of therapy if pulmonary oedema occurs. Avoid abrupt withdrawal and consider dose reduction (e.g. half the dose for 3-7 days) to minimise risk of clinical deterioration. Lactation.
Adverse Reactions
Headache, nasopharyngitis, flushing, fluid retention (e.g. peripheral oedema), hypotension, palpitations, dyspepsia, fatigue, pruritus, rash, anaemia (dose-related), reduced sperm count (reversible).
MonitoringParameters
Monitor hepatic function before initiating therapy and mthly thereafter, and 2 wk after any dose increment. Monitor haemoglobin levels before initiating therapy, mthly during the 1st 4 mth, then quarterly thereafter.
Overdosage
Symptoms: Nausea, vomiting, hypotension, dizziness, sweating and blurred vision. Management: Symptomatic and supportive treatment.
Drug Interactions
Increased bosentan levels w/ CYP3A4 inhibitors (e.g. ketoconazole, ritonavir, diltiazem), CYP2C9 inhibitors (e.g. amiodarone, fluconazole), tacrolimus. Rifampicin initially increases but subsequently decreases bosentan concentration. May decrease plasma levels of warfarin, statins (e.g. simvastatin, lovastatin), hormonal contraceptives, sildenafil, tadalafil.
Potentially Fatal: Increased risk of hepatotoxicity may occur w/ glibenclamide. Ciclosporin markedly increases bosentan concentration.
Food Interaction
Decreased bosentan levels w/ St John's wort. Increased bosentan concentration w/ grapefruit juice.
Lab Interference
Abnormal LFT.
Action
Description: Bosentan, an endothelium-receptor antagonist blocks endothelin receptors on vascular endothelium and smooth muscle promoting vasodilation. It improves exercise capacity and clinical worsening in patients w/ pulmonary arterial HTN.
Pharmacokinetics:
Absorption: Bioavailability: Approx 50%. Time to peak plasma concentration: 3-5 hr after oral admin.
Distribution: Volume of distribution: Approx 18 L. Plasma protein binding: >98% highly bound (mainly to albumin).
Metabolism: Metabolised by CYP3A4 and CYP2C9 isoenzymes.
Excretion: Excreted primarily in the bile as metabolites and <3% of the oral dose is excreted in the urine as unchanged drug. Terminal half-life: Approx 5 hr.
Storage
Store between 20-25°C.
References
Anon. Bosentan. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 07/06/2013.

Buckingham R (ed). Bosentan. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 07/06/2013.

Joint Formulary Committee. Bosentan. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 07/06/2013.

McEvoy GK, Snow EK, Miller J et al (eds). Bosentan. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 07/06/2013.

Tracleer Tablet (Actelion Pharmaceuticals US, Inc). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 07/06/2013.

Tracleer Tablet (Actelion Pharmaceuticals US, Inc). U.S. FDA. https://www.fda.gov/. Accessed 07/06/2013.

Disclaimer: This information is independently developed by MIMS based on Bosentan 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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