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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of 10 oral doses of phenylpropanolamine hydrochloride 25 mg four times a day on blood pressure and heart rate in Korean patients with hypertension controlled by hydrochlorothiazide was studied. A randomized, placebo-controlled, crossover, double-blind study design was used. Twenty Korean patients with mild hypertension controlled by hydrochlorothiazide were recruited from an ambulatory-care clinic. Blood pressure and heart rate were measured in triplicate before treatment, after a five-day washout period between phases of treatment, and two hours after the last dose in each phase of treatment. Eighteen patients completed both phases of treatment, and one patient completed only the placebo phase. Mean baseline values for systolic and diastolic blood pressures and heart rate before the placebo phase did not significantly differ from mean baseline values before the phenylpropanolamine phase. Comparison of mean baseline values for systolic and diastolic blood pressures and heart rate with mean after-treatment values showed no clinically relevant or statistically significant changes for the 19 patients who completed the placebo phase or the 18 patients who completed the phenylpropanolamine phase. There was no significant difference between the mean change in systolic blood pressure, diastolic blood pressure, or heart rate when the phenylpropanolamine phase was compared with the placebo phase. Phenylpropanolamine hydrochloride 25 mg p.o. four times a day (total, 10 doses) given to Korean patients with hypertension controlled by hydrochlorothiazide did not affect blood pressure or heart rate according to single-point outcome measurements.
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PMID:Effect of phenylpropanolamine hydrochloride on blood pressure in Korean patients with hypertension controlled by hydrochlorothiazide. 155 Dec 98

Phenylpropanolamine (PPA) is contained in about 106 products, over half of which are available over-the-counter (OTC). Most are cough/cold remedies; nine are OTC diet aids. More than nine million Americans were using OTC diet aids in 1981, making PPA the fifth most used drug in the United States, responsible for over $200 million in revenues. The safety of PPA remains controversial. Although most controlled studies indicate minimal pressor effects with recommended doses, adverse drug reactions (ADRs) continue to be documented. Since 1965, 142 ADRs have been reported in 85 studies, 69% of these in North America. Many such cases may go unrecognized. About two thirds of all ADRs occurred in females and in patients under 30. Of ADRs attributed to legitimately sold PPA products, 85% occurred after consumption of OTC products versus only 15% after prescription drugs. The PPA product often contained combination ingredients, or PPA was consumed along with additional drugs. An overdose of PPA was taken in about a third of the cases. After ingestion of non-overdose amounts, 82% of the ADRs were severe. The most frequent side effects involved symptoms compatible with acute hypertension, with severe headache the most common complaint. Twenty-four intracranial hemorrhages, eight seizures, and eight deaths (most due to stroke) were associated with PPA ingestion. We have summarized these data in an effort to alert clinicians to the prevalence of usage of PPA products and the potential for adverse effects. In patients who present with elevated blood pressure or signs of acute hypertension, especially hypertensive encephalopathy of undetermined origin, we recommend inquiry about recent ingestion of PPA-containing diet aids and cough/cold products and suggest having such patients remain upright rather than supine.
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PMID:Adverse drug effects attributed to phenylpropanolamine: a review of 142 case reports. 220 Feb 64

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.
Hypertension 1988 Mar
PMID:Phenylpropanolamine and other over-the-counter vasoactive compounds. 328 Apr 97

Phenylpropanolamine (PPA) overdose can cause severe hypertension, intracerebral hemorrhage, and death. We studied the efficacy and safety of propranolol in the treatment of PPA-induced hypertension. Subjects received propranolol either by mouth for 48 hours before PPA or as a rapid intravenous infusion after PPA. PPA, 75 mg alone, increased blood pressure (31 +/- 14 mm Hg systolic, 20 +/- 5 mm Hg diastolic), and propranolol pretreatment antagonized this increase (12 +/- 10 mm Hg systolic, 10 +/- 7 mm Hg diastolic). Intravenous propranolol after PPA also decreased blood pressure. Left ventricular function (assessed by echocardiography) showed that PPA increased the stroke volume 30% (from 62.5 +/- 20.9 to 80.8 +/- 22.4 ml), the ejection fraction 9% (from 64% +/- 10% to 70% +/- 7%), and cardiac output 14% (from 3.6 +/- 0.6 to 4.1 +/- 1.0 L/min). Intravenous propranolol reversed these effects. Systemic vascular resistance was increased by PPA 28% (from 1710 +/- 200 to 2190 +/- 700 dyne X sec/cm5) and was further increased by propranolol 22% (to 2660 +/- 1200 dyne X sec/cm5). We conclude that PPA increases blood pressure by increasing systemic vascular resistance and cardiac output, and that propranolol antagonizes this increase by reversing the effect of PPA on cardiac output. That propranolol antagonizes the pressor effect of PPA is in contrast to the interaction in which propranolol enhances the pressor effect of norepinephrine. This is probably because PPA has less beta 2 activity than does norepinephrine.
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PMID:Propranolol antagonism of phenylpropanolamine-induced hypertension. 398 72

Hypertension, severe headache, and grand mal seizures developed in a 13-year-old girl after ingestion of one nonprescription diet pill containing phenylpropanolamine and caffeine. This case is at least the sixth report of seizures with phenylpropanolamine use in children or adolescents. Phenylpropanolamine ingestion must be included in the differential diagnosis of young patients, particularly adolescents, in whom acute neurological symptoms develop.
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PMID:Phenylpropanolamine-associated CNS complications in children and adolescents. 642 18

Phenylpropanolamine (PPA) is a drug that has been associated with serious side effects including stroke. It is often combined with caffeine in diet preparations and "look-alike" pills. In order to determine if PPA/caffeine can lead to stroke in normotensive and/or hypertensive rats, we administered the combination in six times the allowed human dose calculated on a per weight basis for the rats two times per day for five days. Subarachnoid and cerebral hemorrhage was noted in 18% of the hypertensive rats. A single PPA/caffeine administration (same dose) lead to acute hypertension in both the normotensive and hypertensive animals. These results suggest that PPA/caffeine can lead to cerebral hemorrhage in previously hypertensive animals when administered in greater than the allowed dosage. An acute elevation in blood pressure may be a contributing factor.
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PMID:Cerebral hemorrhage associated with phenylpropanolamine in combination with caffeine. 669 15

Phenylpropanolamine hydrochloride is an amphetamine-like substance that is found in 64 different over-the-counter preparations for colds and appetite suppression. It is also found in numerous prescription drugs. Recently, it has been reported to cause symptoms of sympathomimetic-like effects, such as severe hypertension, hypertensive crisis, and possible renal failure. Also, several cases of psychotic episodes while taking phenylpropanolamine have been reported. This is the report of seven patients who have experienced acute CNS effects. These effects range from stimulation of the medullary respiratory center to tremor, restlessness, increased motor activity, agitation, and hallucinations.
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PMID:Amphetamine-like reactions to phenylpropanolamine. 745 88

The acceptance of medication as a legitimate adjunct to diet and behavior modification in the treatment for obesity is an emerging phenomenon spurred by advances in understanding the biologic basis of body weight regulation and by the demonstration of safe and effective chronic maintenance of weight loss using a pharmacobehavioral approach. The decision to medicate for obesity depends on good clinical judgment based on such considerations as body mass index; body composition; body fat dissociation; age; sex; and comorbid conditions, such as diabetes and hypertension. Several nonadrenergic agents and a serotonergic agent have FDA-approved indications for weight loss. Phenylpropanolamine is available over the counter. Clinical trials support the efficacy of fluoxetine and ephedrine or caffeine in producing weight loss, although these agents do not have FDA-approved indications for treatment for obesity. In addition, new agents are being developed or are anticipated for approval. The use of existing agents in combination and their use adjunctive to diet and behavioral approaches to obesity treatment are fertile areas for research. The expectant attention to this subject is demanded by the imperative that the health in one three people in the United States is adversely affected by obesity.
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PMID:Medicating the obese patient. 897 57

More than 170 over-the-counter (OTC) preparations contain a sympathomimetic agent as the active ingredient. Nonprescription medicines are consumed commonly in our society. Phenylpropanolamine, an alpha-adrenergic agonist as well as a popular decongestant, is consumed at a massive volume of 5 billion doses annually. Over-the-counter sympathomimetics have been reported to cause hypertension and arrhythmias. Despite the ability to cause these potentially serious adverse effects and the high-volume consumption of these agents, the medical literature until recently has been scant in reporting adverse events. We report symptomatic ventricular arrhythmia and presyncope in a 36-year-old pregnant woman who consumed relatively high doses of two OTC cold remedies simultaneously. Increased physician awareness of the potential side effects associated with OTC sympathomimetics as well as improved level of patient education are needed. Finally, we support the calls for more prominent warning labels on some selected OTC preparations, including OTC sympathomimetics.
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PMID:Over-the-counter sympathomimetics: a risk factor for cardiac arrhythmias in pregnancy. 985 29

Quality and number of subjects in blinded controlled clinical trials about the nutrition and dietary supplements discussed here is variable. Glucosamine sulfate and chondroitin sulfate have sufficient controlled trials to warrant their use in osteoarthritis, having less side effects than currently used nonsteroidal anti-inflammatory drugs, and are the only treatment shown to prevent progression of the disease. Dietary supplements of ephedrine plus caffeine for weight loss (weight loss being the current first line recommendation of physicians for osteoporosis) show some promise, but are not sufficient in number of study subjects. Phenylpropanolamine is proven successful in weight loss. Both ephedrine and phenylpropanolamine have resulted in deaths and hence are worrisome [table: see text] as an over-the-counter dietary supplement. Other commonly used weight loss supplements like Cola acuminata, dwarf elder, Yohimbine, and Garcinia camborgia are either lacking controlled clinical trials, or in the case of the last two supplements, have clinical trials showing lack of effectiveness (although Garcinia has been successful in trials as part of a mixture with other substances, it is unclear if it was a necessary part of the mixture). Safety of these weight loss supplements is unknown. Chromium as a body building supplement for athletes appears to have no efficacy. Creatine may help more in weight lifting than sprinting, but insufficient study subjects and safety information make more studies necessary. Carbohydrate loading is used commonly before endurance competitions, but may be underused as it may be beneficial for other sport performances. Supplements for muscle injury or cramps have had too few studies to determine efficacy. Although proper rehydration with fluids and electrolytes is necessary, a paucity of actual studies to maximize prophylactic treatment for exercise induced cramping still exists. Nutritional supplements for cardiovascular disorders are generally geared to prevention. The United States Department of Agriculture has good recommendations to prevent atherosclerosis; a stricter version by Ornish was shown to reverse coronary heart disease, and the low meat, high fruit, and vegetable DASH diet has been found to decrease hypertension. The epidemiologic studies of hyperhomocysteinemia are impressive enough to give folic acid (or vitamin B6 or B12) supplements to those with elevated homocysteine levels and test patients who have a history of atherosclerotic disease, but no controlled clinical trials have been completed. Soluble fiber has several positive studies in reduction of cholesterol levels and generally is accepted. The data on vitamin E are the most confusing. This vitamin was not helpful in cerebrovascular prevention in China and not helpful at relatively small doses (50 mg) in the United States or Finland against major coronary events. Levels of 400 mg appeared to decrease cardiovascular disease in the United States in studies based on reports by patients and in one large clinical trial. Vitamin E also was successful in prevention of restenosis after PTCA in one clinical trial. Both of these clinical trials need to be repeated in other developed country populations. Some nutritional and dietary supplements are justifiably useful at this point in time. Several meet the criteria of a late Phase 3 FDA clinical trial (where it would be released for public use), but many dietary supplements have insufficient numbers of studies. Some deaths also have occurred with some supplements. If these supplements were required to undergo clinical trials necessary for a new drug by the FDA, they would not be released yet to the public. Several nontoxic supplements appear promising, though need further study. Because they have essentially no toxicity (such as folic acid with B12, soluble fiber, and vitamin E) and may have efficacy, some of these supplementations may be useful now, without randomized clinical trials.
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PMID:Nutrition and dietary supplements. 1051 85


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