RT Book, Section
A1 Moote, Rebecca
A1 Attridge, Rebecca L.
A1 Levine, Deborah J.
A2 DiPiro, Joseph T.
A2 Yee, Gary C.
A2 Posey, L. Michael
A2 Haines, Stuart T.
A2 Nolin, Thomas D.
A2 Ellingrod, Vicki
SR Print(0)
ID 1182435532
T1 Pulmonary Arterial Hypertension
T2 Pharmacotherapy: A Pathophysiologic Approach, 11e
YR 2020
FD 2020
PB McGraw-Hill Education
PP New York, NY
SN 9781260116816
LK accesspharmacy.mhmedical.com/content.aspx?aid=1182435532
RD 2024/04/24
AB KEY  CONCEPTS  Pulmonary  arterial  hypertension  (PAH)  is  defined  as  a  mean  pulmonary  artery  pressure  (mPAP)  ≥25  mm  Hg  at  rest  with  a  pulmonary  wedge  pressure  or  left  ventricular  end-diastolic  pressure  (LVEDP)  ≤15  mm  Hg  and  a  pulmonary  vascular  resistance  (PVR)  >3  Wood  units  (WU)  measured  by  right  cardiac  catheterization.  Patients  with  PAH  present  with  exertional  dyspnea,  fatigue,  weakness,  and  exertion  intolerance.  As  the  disease  progresses,  symptoms  of  right  heart  dysfunction  and  failure,  such  as  dyspnea  at  rest,  lower  extremity  edema,  chest  pain,  and  syncope,  may  be  present.  The  definitive  diagnosis  of  PAH  is  done  with  a  right  heart  catheterization.  The  right  heart  catheterization  provides  important  prognostic  information  and  can  be  used  to  assess  pulmonary  vasoreactivity  prior  to  initiating  therapy.  Goals  of  treatment  are  to  alleviate  symptoms;  improve  quality  of  life,  functional  class,  and  exercise  capacity;  slow  disease  progression;  and  improve  survival.  Nonpharmacologic  therapy,  including  counseling  on  pregnancy  avoidance,  immunizations,  and  low-sodium  diets,  should  be  provided  to  all  patients  with  PAH.  Conventional  therapy  of  PAH  includes  oral  anticoagulants,  diuretics,  oxygen,  and  digoxin.  Prostacyclin  analogs  such  as  epoprostenol,  treprostinil,  and  iloprost  induce  potent  vasodilation  of  pulmonary  vascular  beds  and  are  typically  reserved  for  WHO  functional  class  III  and  IV  patients.  Only  epoprostenol  has  demonstrated  improved  survival.  Patients  with  WHO  functional  class  II  or  III  are  commonly  initiated  on  oral  therapy  for  PAH.  Options  include  endothelin-receptor  antagonists,  phosphodiesterase-5  inhibitors,  riociguat,  and  selexipag.  These  agents  have  been  shown  to  improve  exercise  capacity,  functional  class,  and  hemodynamics  in  PAH.  Calcium  channel  blockers  are  only  considered  in  a  small  number  of  patients  who  have  a  positive  response  to  acute  vasoreactivity  testing.  A  very  small  number  of  patients  have  a  long-term  response  to  calcium  channel  blockers.  Combination  therapy  may  address  more  than  one  mechanism  causing  PAH.  Combination  therapy  may  be  initiated  sequentially  or  as  the  initial  regimen  in  patients  with  worse  functional  classes.  Evidence  demonstrates  that  initial  combination  therapy  is  associated  with  a  significant  reduction  in  time  to  clinical  failure  and  PAH  hospitalizations.