Treprostinil
Mechanism :
Treprostinil is a direct vasodilator of both pulmonary and systemic arterial vascular beds; also inhibits platelet aggregation.
Indication :
- Pulmonary arterial hypertension
Contraindications :
Injection/inhalation: No contraindications
Oral: Severe hepatic impairment (Child-Pugh class C).
Dosing :
Injectable (≥16 years):
Initial: 1.25 ng/kg/min continuous SC/IV infusion (0.625 ng/kg/min if not tolerated).
Titrate by no more than 1.25 ng/kg/min every week x first 4 weeks, then no more than 2.5 ng/kg/min every week. Max: 40 ng/kg/min.
Oral tablet (≥18 years):
Initial: 0.25 mg PO BID with food, taken ~12 hours apart. Increase dose as tolerated to achieve optimal clinical response by increments or 0.25-0.5 mg BID every 3-4 days.
Adverse Effect :
Infusion site reaction, pain, headache, nausea, diarrhea, vasodilation, jaw pain, rash, dizziness, edema, pruritus, hypotension.
Interaction :
CYP2C8 Inhibitors (Strong): May increase the serum concentration of Treprostinil.
Rifampin: May decrease the serum concentration of Treprostinil.
Thrombolytic Agents: May enhance the adverse/toxic effect of Prostacyclin Analogues.
Hepatic Dose :
Injectable
Mild to moderate hepatic impairment: Begin dose at 0.625 ng/kg/min.
Severe hepatic impairment: Dosing has not been studied, avoid use.
Oral inhalation
Mild to moderate hepatic impairment: Dose should be titrated slowly.
Severe hepatic impairment: Dosing has not been studied, avoid use.
Oral Preparation:
Mild hepatic impairment: Dose should be halved, and increments of this same dose every 12 hours every 3 to 4 days.
Moderate hepatic impairment: drug is not recommended.
Severe hepatic impairment: drug use is contraindicated.