RESUMEN
Phenylpropanolamine (PPA) is a sympathomimetic agent, very similar in structure to amphetamine. In the United States, it is present in over 130 medications, primarily anorectic agents and cough and cold remedies, many available without a prescription. The effects of PPA on blood pressure (BP) remain controversial and its mechanisms of action unknown. We studied acute (1 and 2 hours) and 2-week effects of a daily dose of 75 mg of sustained release PPA administered to 14 normal volunteers. Measurements of heart rate, BP, and plasma catecholamines (CA) were made with the subject in the supine and standing positions, and upon gripping a hand dynamometer for 5 minutes. Although systolic BP across all postures and sampling times was significantly higher when subjects were taking PPA in comparison to placebo (F = 5.95, p = 0.03), in no subject did the increase in BP reach hypertensive or clinically significant levels and no substantial changes in CA levels were found. Our study population was relatively young and normotensive; even such a small BP increase may pose greater problems for hypertensive, obese subjects likely to be users of diet aids. Strenuous isometric exercise did not cause any greater increase in BP or CA after subjects took PPA versus placebo. PPA blood levels 24 hours after the last of 14 daily doses were similar to levels 1 and 2 hours after an initial dose. We conclude from these data that recommended doses of PPA have only minimal sympathetic nervous system (SNS) and cardiovascular effects in young, healthy, normotensive populations at the times and dose studied.
Asunto(s)
Presión Sanguínea/efectos de los fármacos , Epinefrina/sangre , Frecuencia Cardíaca/efectos de los fármacos , Norepinefrina/sangre , Fenilpropanolamina/farmacología , Sistema Nervioso Simpático/fisiología , Adulto , Femenino , Humanos , Contracción Isométrica , Masculino , Postura , Valores de Referencia , Sistema Nervioso Simpático/efectos de los fármacosRESUMEN
A 16-month-old child is presented who developed severe "stress hyperglycemia" with the onset of a respiratory distress syndrome. The serum glucose rose from 74 mg/dl to 520 mg/dl and returned to 52 mg/dl all within 24 h. These variations in serum glucose were paralleled by a similar marked increase in plasma cortisol concentration (from 41 to 90 to 36 micrograms/dl). The patient was receiving no iv dextrose and required no exogenous insulin. These data are consistent with a diagnosis of stress hyperglycemia. This report is unique in that, to our knowledge, stress hyperglycemia to levels greater than 350 mg/dl have not been previously reported in either adults or children.