Determinants of the pressor effect of phenylpropanolamine in healthy subjects.
Phenylpropanolamine (PPA) is frequently used in over-the-counter diet aids and cold medicines, In view of concern about the safety of this sympathomimetic agent, we undertook a double-blind, multicenter clinical trial to determine the factors that influence the pressor effect of short-term oral administration of PPA in healthy individuals. Eight hundred eighty-one healthy individuals in four categories of body weight were randomized to receive placebo capsules three times per day (n = 286), a 75-mg sustained-release PPA hydrochloride preparation once per day (n = 296) followed by two doses of placebo capsules, or a 25-mg immediate-release PPA hydrochloride preparation three times per day (n = 299). The median age of the study population was 28 years, 56% were men, 73% were white, and 47% were in excess of 30% above their ideal body weight. Measurements of pulse rate and supine and standing blood pressure were made 11 times during the day of PPA administration. A statistically significant but clinically unimportant pressor effect for the short-term administration of PPA was observed. The effect occurred in the first 6 hours after administration and was greater in the sustained-release group. Significant independent determinants of the pressor effect of PPA were baseline diastolic blood pressure, baseline body weight, and treatment.
Blackburn
G L
GL
Department of Surgery, Harvard Medical School, New England Deaconess Hospital, Boston, MA 02215.
Morgan
J P
JP
Lavin
P T
PT
Noble
R
R
Funderburk
F R
FR
Istfan
N
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects*; D001835:Body Weight; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010665:Phenylpropanolamine / Q000008:administration & dosage / Q000494:pharmacology*; D011187:Posture; D011897:Random Allocation; D013997:Time Factors
D003692:Delayed-Action Preparations; D010665:Phenylpropanolamine