Home Drug Guide Bosentan

Drug Guide

Generic Name

Bosentan

Brand Names Tracleer

Classification

Therapeutic: Treats pulmonary arterial hypertension (PAH)

Pharmacological: Endothelin receptor antagonist

FDA Approved Indications

Pulmonary arterial hypertension (PAH) in adults

Mechanism of Action

Bosentan is an oral endothelin receptor antagonist that blocks endothelin-1 from binding to its receptors (ETA and ETB), leading to vasodilation and decreased pulmonary artery pressure.

Dosage and Administration

Adult: Start with 62.5 mg twice daily for 4 weeks, then increase to 125 mg twice daily based on tolerance and clinical response.

Pediatric: Not approved for pediatric use.

Geriatric: No specific dosage adjustment recommended; assess hepatic function prior.

Renal Impairment: No dosage adjustment required, but monitor closely.

Hepatic Impairment: Contraindicated in patients with severe hepatic impairment (Child-Pugh C). Use caution in moderate impairment.

Pharmacokinetics

Absorption: Rapid absorption with peak plasma concentrations in 3-5 hours.

Distribution: Widely distributed; protein binding approximately 98%.

Metabolism: Primarily via hepatic CYP2C9 and CYP3A4 enzymes.

Excretion: Metabolites excreted mainly via the feces; minimal renal excretion.

Half Life: 5-12 hours.

Contraindications

Severe hepatic impairment (Child-Pugh C)
Use in pregnancy unless benefits outweigh risks

Precautions

Monitor liver function regularly during therapy.
Use with caution in pregnancy; risk of fetal harm.

Adverse Reactions - Common

Headache (Frequent)
Flushing (Frequent)
Edema (Frequent)
Liver enzyme elevation (Frequent)

Adverse Reactions - Serious

Hepatotoxicity (Less common, but serious)
Anemia (Uncommon)
Decreased hemoglobin (Uncommon)
Hypersensitivity reactions (Rare)

Drug-Drug Interactions

Cyclosporine (increases bosentan levels)
Glyburide (potential increase in hypoglycemia)
Other hepatotoxic drugs

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor liver function tests (LFTs) before initiating and periodically during therapy; assess for signs of liver injury.

Diagnoses:

Risk for hepatic injury
Impaired gas exchange

Implementation: Administer as per dosing schedule, monitor LFTs regularly, educate patient about liver toxicity symptoms, avoid pregnancy.

Evaluation: Liver function remains stable; therapeutic goals of reducing pulmonary arterial pressure are achieved.

Patient/Family Teaching

Report any symptoms of liver dysfunction (jaundice, dark urine, right upper quadrant pain).
Avoid pregnancy; use effective contraception during treatment.
Inform about potential side effects like headache, flushing, edema.
Do not stop medication abruptly without consulting healthcare provider.

Special Considerations

Black Box Warnings:

Hepatotoxicity: Severe liver injury has been reported. Liver function must be monitored during therapy.

Genetic Factors: None specified.

Lab Test Interference: May cause elevations in hepatic aminotransferases, which require confirmation.

Overdose Management

Signs/Symptoms: Liver toxicity, hypotension, dizziness.

Treatment: Supportive care, monitor liver function, symptomatic treatment. No specific antidote.

Storage and Handling

Storage: Store at room temperature, protected from moisture and light.

Stability: Stable under recommended storage conditions.