Hypertensive responses induced by phenylpropanolamine in anorectic and decongestant preparations.

The acute effects of a single capsule of each of two phenylpropanolamine-containing preparations were determined in a group of healthy young adults, by means of a double-blind comparison with matching placebo preparations. Supine diastolic blood-pressure rose to 100 mm Hg or more in 12 out of 37 subjects taking an anorectic preparation ('Trimolets'; 85 mg phenylpropanolamine per capsule) and in 4 out of 34 subjects taking a decongestant preparation ('Contac 500'; 50 mg phenylpropanolamine per capsule). 20 of the subjects taking trimolets reported adverse side effects. The frequency and extent of the hypertensive response to high-dose phenylpropranolamine-containing preparations suggest that clinical use of such preparations should be reviewed and that their availability without prescription may not be appropriate.