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Pharmacodynamics of phenylpropanolamine: aspects of safety and efficacy in humans

Phenylpropanolamine (PPA), a synthetic sympathomimetic amine, is widely used as a nasal decongestant and as an appetite suppressant. Much controversy exists regarding the efficacy of the drug as an anorectic agent, the related adverse reactions caused by the relatively high doses required for appetite suppression and the potential of this drug for abuse. Whilst numerous studies have been carried out to assess the central and cardiovascular safety of PPA and many investigations have been performed to evaluate efficacy in terms of weight loss in humans, there is a relative paucity of information regarding the effects of PPA on appetite and food intake. A pilot trial was conducted to determine the feasiblility of a multidimensional approach to evaluate the safety and efficacy of PPA as ananorectic agent in humans. Eight normotensive caucasian women who were overweight participated in a randomised double-blind cross-over comparison of PPA (75 mg) and placebo and were dosed to steady-state on a 12-hour fixed-dose schedule for a period of eleven weeks. Aspects of efficacy evaluated included the effects of PPA on hunger, appetite and satiety,salivation, macro-nutrient food intake and body weight. Standardised scales were used to quantitatively assess the possible subjective mood and behavioural reinforcing effects of PPA. Supine systolic and diastolic blood pressures were monitored continually throughout the trial. In addition, peak and trough blood samp1es were taken to monitor serum concentrations of PPA reached at steady-state and patient compliance with the dosing schedule. An adaptation of a published reverse-phase high performance liquid chromatographic (HPLC) assay for PPA in serum using U.V. detection at 210 nm is presented. A significant decrease in body weight, salivation, total food intake and carbohydrate consumption was demonstrated following PPA administration. Phenylpropanolamine produced significant decrements in subjective reports of hunger and appetite, whilst apparently having little effect on satiety. No significant changes were observed for blood pressures and PPA did not produce significant mood alterations or behavioural reinforcing effects. The study demonstrates the feasibility of using this muti-faceted approach, with certain design modifications, to evaluate the overall safety and efficacy of PPA as an appetite suppressant.

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:rhodes/vital:3785
Date January 1993
CreatorsPetrie, Lauri René
PublisherRhodes University, Faculty of Pharmacy, Pharmacy
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageEnglish
TypeThesis, Masters, MSc
Format125 leaves, pdf
RightsPetrie, Lauri René

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