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Daniela Brady, RNResearch Nurse ClinicianPulmonary Hypertension CenterColumbia University Medical Center

Disclosures� United Therapeutics, Speaker’s Bureau

Prostacyclin (PGI2)� Naturally occuring prostaglandin metabolite of arachidonic

acid (PGI2)� Continuously produced by the vascular endothelium by

prostacyclin synthase � A relative deficiency of prostacyclin may contribute to the

pathogenesis of PAH

Prostacyclin pathway

Arachidonic acid Prostaglandin I 2

Prostacyclin (PGI 2)

cAMP

Vasodilation and antiproliferation

Smooth muscle cells

Prostacyclin derivatives

+

Pulmonary artery in

patient with PAH

PGI2 and its derivatives have potent vasodilatory, antiproliferative and antithrombotic effects on vascular smooth muscl e cells.

PGI2: Mechanism of Action

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Main Properties of Prostacyclin� Systemic and pulmonary vasodilation via relaxation of vascular

smooth muscle cells

� Inhibition of platelet aggregation

� Inhibition of vascular cell migration and proliferation

� Cytoprotective effect: prevention of ischemic cell injury

� Improvement in pulmonary clearance of endothelin-1

� Possible inotropic effect

Prostanoids� Developed to mimic the favorable characteristics of

prostacyclin (PGI2) but offer alternate modes of delivery� Longer half-life or other features (e.g.

thermostability) to improve risk-benefit ratio and/or quality of life issues associated with epoprostenol delivery

Intravenous Epoprostenol (PGI2)� Rapidly hydrolyzed in circulation (t1/2 = 3 min)� Unstable at room temperature – requires ice packs � thermo-stable formulation FDA approved; not tested in children

� Many potential side effects� Requires continuous IV infusion for sustained effect

� PGI2 was first used as an acute vasodilator in 1980 in a child with IPAH

FDA approved 1995; FC III/IV PAH

Epoprostenol vs. Conventional TherapyChange from Baseline in 6-Minute Walk Test

Epoprostenol (11; 41) Conventional Therapy (14; 40)

-60

-40

-20

0

20

40

60

80

Met

ers

Week 1 Weeks 8 and 12 (Mean)

Rubin, et al. Ann Intern Med, 1990; Barst, et al. NEJM, 1996

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Barst, RJ. et al. Circulation 1999

K-M survival curves comparing survival of nonrespon ders (n=24) treated with long-term PGI2 with survival of nonresponders (n=22 ) for whom PGI2 was indicated but unavailable

Epoprostenol and Survival in Children

Yung, D. et al. Circulation 2004;110:660-665

Kaplan-Meier curves for survival and treatment succ ess in patients in more recent medical era (n=44)

Pediatric PAH Survival and Treatment success in “Epo Era”

Epoprostenol (Flolan)Epoprostenol –thermostable (Veletri)

Epoprostenol delivery system (CADD pump) IV/SQ Prostanoid Side Effects

� Flushing�Headache�Diarrhea �Nausea/emesis� Jaw pain� Leg pain

�Hypotension�Dizziness� Syncope�Delivery complications� Site pain� Site reaction

Vary according to drug and route of delivery

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Epoprostenol Delivery System Complications �Local site infection �Catheter related bloodstream infections�CADD pump malfunction� bolus effect� cessation phenomenon – due to short half life

of epoprostenol

Epoprostenol� Prostacyclin is effective in treating group 1 PAH� improve pulmonary hemodynamics� prolong survival� improve symptoms� extend exercise tolerance

� Caution� numerous side effects� inconvenience and risks with continuous infusion

Pediatric PAH Indications for IV epoprostenol: general guidelines�WHO FC III or IV patient (presence of right heart

failure)� Non-responsive to AVT� Very young patients (<7yrs); maximize benefit

during rapid lung development� Syncope (particularly if already on oral tx)� Failed oral trial (how long do you wait?)� Consider a lower threshold knowing the natural

history in children is worse than adults, untreated

Treprostinil (remodulin)� Longer acting prostacyclin analogue� (t ½= 4 hours)

� Stable at room temperature� No ice packs or refrigeration required� Mixed cassettes last 48 hours

� SQ or IV form

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Treprostinil Delivery Systems� CADD Legacy� Chrono 5� Minimed 407 C (IV/SQ)

IV/SC Bioequivalence Study

Laliberte et al. J Cardiovasc Pharmacol. 2004.

Hour0 12 24 36 48 60 72 84 96

10-3

10-2

10-1

100

Trep

rost

inil

conc

entr

atio

n, n

g/m

L

IVSC

Steady state

● IV Remodulin▲SC Remodulin

Treatment considerations: IV vs SQ� Provider/patient preferences� Financial considerations� PAH center experience� Family/care-giver support� Body image concerns� Low pain threshholds

SQ Treprostinil Site Pain Considerations

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Site Pain Management Approaches: Local/Topical options� First line remedies� Ice� Warm bath with Epsom salts� Aloe vera gel, arnica oil, capsaicin cream

� Anesthetic Agents� Lidocaine 5% patches/lidocaine cream� Caladryl lotion

� Vasoconstrictive agents� Hemorrhoid ointment

� PLO Gel compounds

Pain Management Approaches: Systemic options� Histamine H1 receptor antagonists� Loratadine, fexofenadine HCL, cetirizine HCL

� Histamine H2 receptor antagonists� Ranitidine, famotidine

� Non-opioid analgesics� Ibuprofen, acetaminophen

� GABA analogs� Gabapentin, pregabalin

� Opioid analgesics (for severe pain)� Tramadol, fentanyl patch, hydrocodone with acetaminophen

� Antidepressants� Amitriptyline

IV Epoprostenol to IV Treprostinil transition � Successful transition of 13 pediatric PAH pts

from IV epo to IV treprostinil� 2 deaths, 2 transitions to other therapies� Transitioned in hospital over 24 hours (rapid or slow)� Patients maintained their exercise capacity� Higher dose, fewer side effects� Several central line infections however, reported

before current recommendations for treprostinil line care were implemented

Ivy DD, et al. Am J Cardiol, 2007

IV Prostanoids: Minimizing risk for Catheter Related- Blood Stream Infections (CR-BSI)

� Single center experience using closed-hub system and waterproofing precautions during showering with IV prostanoids in children to minimize CR-BSI� 50 patients receiving prostanoids � Closed-hub system and maintenance of dry catheter hub

connections significantly reduced the incidence of CR-BSI (particularly infections caused by gram-negative pathogens) in patients receiving intravenous treprostinil.

Ivy DD, et al. Infection Control and Hospital Epidemiology, 2009.

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Rates of CR-BSI pre and post implementation of Closed-Hub system with protected connections

Ivy DD, et al. Infection Control and Hospital Epidemiology, 2009.

SQ Treprostinil for PH associated with CLD of infancy� Case series of 5 infants successfully treated (off-label)

with SQ treprostinil at Columbia University Medical Center� General characteristics� CLD� Former premature infants (born at 23-26 weeks)� Birth weight range 470-635 grams� 4/5 patients were under 1 year of age at the time of

initiation of therapy

SQ Treprostinil for PH associated with CLD of infancy: Results� All patients had improvement in their respiratory and

inotrope support after treprostinil initiation� There were no local reactions at SC infusion site� No evidence of pain or tenderness at infusion site� 4/5 patients are alive at present (one baby died from

suspected septic shock 2 weeks after initiation of therapy)

Transition of Pediatric PAH Patients from IV Epoprostenol to oral/inhaled agents � Retrospective review of all pediatric IPAH/FPAH

treated at Columbia (1987-2008) who transitioned off IV epo to oral/inhaled drugs� General criteria for transition off included: � FC I/II� Age > 6yrs� PAPm <35mmHg� Normal cardiac index

� Hemodynamics and clinical data were assessed on peak epoprostenol dose vs. off epoprostenol

Melnick L, et al., AJCardiol, 2010

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Transition of Pediatric PAH Patients from IV Epoprostenol to oral/inhaled agents: Results� 14/104 pediatric patients who met general criteria were

transitioned off IV epoprostenol (over several months to years; 4/03-7/08) � 13/14 remained off IV epo on oral/inhaled medications� Hemodynamics, exercise capacity (if able) and WHO

functional class remained stable off epo compared to peak epoprostenol dose. (f/u 7+6 mos); Further improvement in WHO FC was seen post epoprostenol (p<0.005)� All 13 patients are alive at present; (77% ERA, 69%

PDE-5 inhibitor, 38% CCB, 8% iloprost)

Melnick L, et al., AJCardiol, 2010

Summary: Prostanoids in Pediatric PAH� IV epoprostenol still remains the “gold standard” for the

treatment of advanced pediatric PAH� Newer agents have enabled initiation or transition to other

prostanoids and even to oral/inhaled agents in carefully selected patients� Close monitoring of side effects and diligent management are

important for patient compliance and treatment success� Caution should be applied to delay in the institution of

prostanoid therapy when using novel oral agents � As novel agents are developed so are new challenges in

decision making