Determinants of the Pressor Effect of Phenylpropanolamine in Healthy Subjects
- George L. Blackburn, MD, PhD;
- John P. Morgan, MD;
- Philip T. Lavin, PhD;
- Rudolf Noble, MD, PhD;
- Frank R. Funderburk, MA;
- Nawfal Istfan, MD, PhD
- From the Departments of Surgery (Drs Blackburn and Lavin) and Medicine (Dr Istfan), New England Deaconess Hospital, Harvard Medical School, Boston, Mass; the Department of Pharmacology, City University of New York (NY) Medical School (Dr Morgan); Cathedral Hill Obesity Clinic, San Francisco, Calif (Dr Noble); and the Department of Psychiatry, The Johns Hopkins University School of Medicine and Francis Scott Key Medical Center, Baltimore, Md (Mr Funderburk).
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.
(JAMA. 1989;261:3267-3272)
Footnotes
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Reprint requests to the Department of Surgery, Harvard Medical School, New England Deaconess Hospital, 194 Pilgrim Rd, Boston, MA 02215(Dr Blackburn).
