title: Determinants of the pressor effect of phenylpropanolamine in healthy subjects.
abstract: 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.
authors.affiliation: Department of Surgery, Harvard Medical School, New England Deaconess Hospital, Boston, MA 02215.
authors.forename: G L
authors.initials: GL
authors.lastname: Blackburn
authors.forename: J P
authors.initials: JP
authors.lastname: Morgan
authors.forename: P T
authors.initials: PT
authors.lastname: Lavin
authors.forename: R
authors.initials: R
authors.lastname: Noble
authors.forename: F R
authors.initials: FR
authors.lastname: Funderburk
authors.forename: N
authors.initials: N
authors.lastname: Istfan
mesh_terms: 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
chemical_list: D003692:Delayed-Action Preparations; D010665:Phenylpropanolamine