Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1323099 (sympathomimetic)
 2,957 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oral combination preparations (antihistamine + sympathomimetic) are widely used for nasal and sinus congestion without the presence of allergy. The use of antihistamine in these cases may be questioned. Evaluation of the clinical effect of only a sympathomimetic agent on patients with nonallergic rhinitis is performed in a double-blind clinical study on seventy patients. Phenylpropanolamine (50 mg and 100 mg) was compared with placebo. It was found that 100 mg phenylpropanolamine was significantly more active than 50 mg or placebo administered orally as a sustained-release tablet twice daily. No side-effects such as CNS stimulation and influence on blood pressure were seen at any of the dose levels.
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PMID:A double-blind clinical study with Monydrin tablets in patients with non-allergic chronic rhinitis. 37 33

Phenylpropanolamine hydrochloride (PPA-HCL) is a synthetic phenylisopropanolamine sympathomimetic agent which is structurally related to ephedrine and amphetamine. Although its precise mechanism of action has not been conclusively determined, PPA is known to exert cardiovascular effects possibly related to indirect stimulation of beta-adrenergetic receptors in the heart. In addition, through CNS stimulation, PPA is known to act as an appetite suppressant, the anorexigenic effect being much weaker than that of amphetamine. In order to develop a convenient dosage of PPA, a transdermal preparation containing 250 mg PPA has been developed. Transdermal delivery is convenient both in terms of case of application and ready withdrawal of drug if desired. Oral PPA dosage forms are designed to have a fall off period of 6-8 hours to facilitate sleep. Such a drug free period is easily attained using a transdermal system either by removal of the transdermal device or incorporation of a lag period into the design of the system. The bioavailability and in vitro pharmacokinetic characteristics of this novel PPA preparation were compared with those of a reference sustained-release 75 mg Q16 PPA tablet (Acutrim), in a pilot, 3 subject, unblinded, cross-over, single dose study. Subjects fasted from the evening before dosing until 0.5 hours prior to dosing. Patches were removed 24 hours following application. Reportedly effective plasma PPA levels for appetite suppression were recorded after patch application and were comparable to those observed with the reference. Peak plasma PPA levels were slightly higher for the transdermal patch compared with the tablet formulation (93.6 ng/ml versus 80.10 ng/ml respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:In-vivo pharmacokinetic characteristics of a transdermal phenylpropanolamine (PPA) preparation. 182 Aug 95

Phenylpropanolamine, a widely consumed over-the-counter drug, is known to elevate blood pressure, but the mechanism is unknown; it may be both a direct and indirect sympathomimetic. This study investigated the effects of 75-mg sustained-release phenylpropanolamine, 75-mg phenylpropanolamine plus 400-mg caffeine, and 150-mg phenylpropanolamine on blood pressure, plasma norepinephrine, and epinephrine levels in 16 normotensive subjects in a double-blind, placebo-controlled crossover design. Mean peak phenylpropanolamine levels of 317 +/- 26, 152 +/- 17, and 157 +/- 17 ng/mL for 150-mg phenylpropanolamine, 75-mg phenylpropanolamine, and 75-mg phenylpropanolamine plus 400-mg caffeine, respectively, were reached at about 3.6 hours after dosing. The maximal increases in supine diastolic blood pressures after all three phenylpropanolamine-containing drugs were almost three times that after placebo (P less than .05), but peak blood pressures occurred at about 2.3 hours earlier than peak phenylpropanolamine levels. Blood pressure increases correlated with phenylpropanolamine plasma levels (r = .49 for systolic blood pressure and r = .34 for diastolic blood pressure; P less than .0001 for both). Norepinephrine levels increased after the administration of 150-mg phenylpropanolamine and 75-mg phenylpropanolamine plus 400-mg caffeine; norepinephrine increases correlated with phenylpropanolamine levels (r = .34, P less than .0001). The expected increment in norepinephrine induced by standing was significantly decreased by phenylpropanolamine in a dose-dependent mode. The study supports the idea that phenylpropanolamine as both a direct (at alpha -1 and alpha-2 receptors) and an indirect sympathomimetic agent.
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PMID:Dose-dependent response to phenylpropanolamine: inhibition of orthostasis. 189 58

Phenylpropanolamine is a sympathomimetic agent present in over 100 proprietary and prescription anorectics, nasal decongestants, psychostimulants and treatments for premenstrual syndrome. It is often found in street drugs prepared to look like amphetamines. Phenylpropanolamine has precipitated paranoid psychosis, severe anxiety, cerebrovascular accidents and hypertensive crises. Hypertensive crises can be treated with phentolamine. Psychiatric symptoms and anxiety are managed with benzodiazepines.
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PMID:Complications of phenylpropanolamine. 230 Dec 4

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.
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PMID:Determinants of the pressor effect of phenylpropanolamine in healthy subjects. 271 62

Phenylpropanolamine (PPA) is a sympathomimetic drug similar in structure to amphetamine which, in the United States, is present in over 130 medications, primarily decongestants, cough/cold remedies, and anorectic agents. We have reviewed 37 cases (published in North America and Europe since 1960) that received diagnoses of acute mania, paranoid schizophrenia, and organic psychosis and that were attributed to PPA product ingestion. Of the 27 North American case reports, more reactions followed the ingestion of combination products than preparations containing PPA alone; more occurred after ingestion of over-the-counter products than those obtained by prescription or on-the-street; and more of the cases followed ingestion of recommended doses than overdoses. Groups at particular risk appear to be those with a past or family psychiatric history, children under the age of 6 and post-partum women. Failure to recognize PPA as an etiological agent in the onset of symptoms usually led to a diagnosis of schizophrenia or mania, lengthy hospitalization, and treatment with substantial doses of neuroleptics or lithium. While generally safe at recommended doses, PPA can be hazardous to susceptible individuals and we urge physicians to be alert to the potential for PPA related psychiatric reactions. We have compiled an alphabetized table (Table 1: Prescription and Over-the-Counter Products Containing Phenylpropanolamine) allowing busy clinicians quick access to those drugs containing PPA.
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PMID:Psychiatric side effects attributed to phenylpropanolamine. 306 Aug 84

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.
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PMID:The effects of phenylpropanolamine on human sympathetic nervous system function. 325 97

Phenylpropanolamine is a sympathomimetic amine that shares structural similarities with amphetamine and ephedrine. It increases blood pressure primarily by increasing peripheral vascular resistance. This effect is the result of alpha-adrenergic agonist activity largely from both direct stimulation of adrenergic receptors and release of neuronal norepinephrine. As such, it has the potential to interact with other drugs to produce toxic reactions, especially in treated hypertensive patients. Complications have occurred with single oral doses that suggest some normal subjects may be more sensitive to the drug than others. The incidence of serious complications in the general population is small but could be much higher in susceptible individuals (e.g., cardiomyopathic and hypertensive patients). The availability of high-dose phenylpropanolamine-containing preparations without medical supervision is potentially dangerous, and certain restrictions should be imposed on such preparations.
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PMID:Phenylpropanolamine and other over-the-counter vasoactive compounds. 328 Apr 97

Metaiodobenzylguanidine (MIBG) localizes in adrenergic neurons; MIBG labeled with 123I then serves as an analog of norepinephrine, and concentrations of [123I]MIBG reflect sites of adrenergic neurons in organs. Movements of [123I]MIBG into and out of organs were measured by quantitative scintigraphy in man. We perturbed adrenergic neuron function in several ways, and [123I]MIBG concentrations in the heart were subsequently altered in patterns consistent with the concept that [123I]MIBG resides mostly in adrenergic neurons. Uptake of [123I]MIBG into the heart was inhibited by the tricyclic drug, imipramine, and this agent also accelerated the rate of loss of [123I]MIBG. Phenylpropanolamine, a sympathomimetic drug that acts by displacing norepinephrine from neurons, increased the rates of loss of [123I]MIBG from the heart. Exercise was followed by a movement of [123I]MIBG into blood and urine. Generalized autonomic neuropathies were associated with marked diminutions of [123I]MIBG uptake into the heart. We conclude that quantitative scintigraphy in patients will enable determinations of regional disturbances in integrity (by measuring uptake of [123I]MIBG) and function (by measuring rates of loss of [123I]MIBG) of the adrenergic nervous system in the heart.
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PMID:Metaiodobenzylguanidine to map scintigraphically the adrenergic nervous system in man. 365 15

Phenylpropanolamine (PPA) is a sympathomimetic amine and component of many over-the-counter decongestants and anorectic agents. It has been reported to cause elevated blood pressure and even hypertensive crises. The pressor effects with therapeutic doses are not well established. We monitored the effects of acute and chronic PPA dosing using 24-hour ambulatory blood pressure recording as a sensitive method of monitoring blood pressure variability. Eighteen normotensive male subjects were randomly assigned to receive 75 mg PPA (sustained-release preparation) or placebo in a double-blind crossover design with blood pressure monitored on days 1 (D1) and 6 (D6) of each period. There was no significant difference in blood pressure when compared as either 2-hour intervals or 24-hour global means: (placebo) 116/68 (D1), 117/68 (D6); (PPA) 118/69 (D1), 119/69 (D6). Our results document the absence of pressor effect with PPA in therapeutic doses even with repeated measurements and further confirm the reproducibility of 24-hour blood pressure monitoring.
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PMID:The effect of phenylpropanolamine on ambulatory blood pressure. 373 78


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