RT Book, Section
A1 Biaggioni, Italo
A2 Katzung, Bertram G.
A2 Vanderah, Todd W.
SR Print(0)
ID 1176462236
T1 Adrenoceptor Agonists & Sympathomimetic Drugs
T2 Basic & Clinical Pharmacology, 15e
YR 2021
FD 2021
PB McGraw-Hill
PP New York, NY
SN 9781260452310
LK accesspharmacy.mhmedical.com/content.aspx?aid=1176462236
RD 2024/04/23
AB CASE  STUDYA  68-year-old  man  presents  with  a  complaint  of  light-headedness  on  standing  that  is  worse  after  meals  and  in  hot  environments*.  Symptoms  started  about  4  years  ago  and  have  slowly  progressed  to  the  point  that  he  is  disabled.  He  has  fainted  several  times  but  always  recovers  consciousness  almost  as  soon  as  he  falls.  Other  symptoms  include  slight  worsening  of  constipation,  urinary  retention  out  of  proportion  to  prostate  size,  and  decreased  sweating.  He  is  otherwise  healthy  with  no  history  of  hypertension,  diabetes,  or  Parkinson  disease.  Because  of  urinary  retention,  he  was  placed  on  the  α1A  antagonist  tamsulosin,  but  the  fainting  spells  got  worse.  Physical  examination  is  unremarkable  except  for  a  blood  pressure  of  167/84  mm  Hg  supine  and  106/55  mm  Hg  standing.  There  was  an  inadequate  compensatory  increase  in  heart  rate  (from  84  to  88  bpm),  considering  the  magnitude  of  orthostatic  hypotension.  There  is  no  evidence  of  peripheral  neuropathy  or  parkinsonian  features.  Laboratory  examinations  are  negative  except  for  a  low  plasma  norepinephrine  (98  pg/mL;  normal  for  his  age  250–400  pg/mL).  A  diagnosis  of  pure  autonomic  failure  is  made,  based  on  the  clinical  picture  and  the  absence  of  drugs  that  could  induce  orthostatic  hypotension  and  diseases  commonly  associated  with  autonomic  neuropathy  (eg,  diabetes,  Parkinson  disease).  What  precautions  should  this  patient  observe  in  using  sympathomimetic  drugs?  Can  such  drugs  be  used  in  his  treatment?