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

1. Over the last 40 years a range of therapeutic strategies has been introduced for the long term treatment of hypertension. 2. Although safe effective agents are available a significant number of patients are unable or unwilling to take these drugs as long term treatment. 3. Both insufficient efficacy and adverse effects justify the search for new antihypertensive strategies. 4. Recent developments include orally active angiotensin (AT1) receptor antagonists (ARA) which appear to offer the benefits of prevention of angiotensin II effects without the adverse effects of bradykinin potentiation, such as cough, which limit the usefulness of angiotensin converting enzyme (ACE) inhibitors. 5. Imidazoline receptor agonists offer the potential of centrally active antihypertensives without the adverse effects of sedation and dry mouth. Further clinical experience is necessary to confirm whether the clinical efficacy and good tolerability are confirmed with long term use. 6. Both ARA and imidazoline preferring substances offer the bonus of a desirable haemodynamic profile in patients with heart failure and may open new therapeutic avenues in the management of cardiac failure.
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PMID:New therapeutic agents for hypertension. 880 42

Traditional centrally acting antihypertensives have been associated with a high incidence of adverse effects and are no longer recommended as first-line therapy. The newer imidazoline receptor agonists must overcome this reputation if they are to gain recognition as potential first-line agents for hypertension. Methyldopa, a centrally acting alpha(2)-agonist, is characterized by a number of serious adverse reactions that limit its use. Although unpredictable idiosyncratic or hypersensitivity reactions are uncommon, these include hepatitis, myocarditis, and hemolytic anaemia. Less serious problems such as abnormal liver function tests, positive Coombs test, drug-induced fever, and pancreatitis also occur. Central side effects include drowsiness, fatigue, lethargy, sedation, depression, psychotic reactions, nasal stuffiness, impotence, and exacerbation of Parkinsonism. In hypertensive men, methyldopa is less well tolerated than either captopril or propranolol, and up to 20% of patients discontinue therapy because of adverse effects. Clonidine acts primarily as an alpha(2)-agonist but also acts as an agonist at imidazoline receptors in the rostroventrolateral medulla. It is equipotent to most other antihypertensives but is considerably less well-tolerated in comparative trials. The principal adverse effects of clonidine are drowsiness, sedation, lethargy and dry mouth. Reserpine acts primarily by depleting central catecholamine neurotransmitter stores. It was very extensively used in early hypertension trials, but its central side effects of sedation, nasal stuffiness, and severe depression are now considered so undesirable that the drug is seldom prescribed. The imidazoline (I1) agonists moxonidine and rilmenidine act selectively and have very little central alpha(2)-agonist activity. In comparative studies against placebo and other reference antihypertensives, the only adverse effect consistently associated with these drugs was dry mouth (approximate placebo-corrected incidence 10%). Sedation was not pronounced. Withdrawal syndromes are complex pathophysiologic processes and occur with a variety of antihypertensive drugs. Cessation of therapy with clonidine and, to a lesser extent, methyldopa may result in a severe withdrawal syndrome characterized by restlessness, sweating, anxiety, tremor, palpitations, and headache. There may be a rapid rise in blood pressure, often with a true "rebound" to higher than pretreatment levels. Plasma and urinary catecholamine levels are increased, and fatalities have been reported. It is important to stress that such a syndrome has not been recorded, in animal or human studies, with either moxonidine or rilmenidine.
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PMID:Aspects of tolerability of centrally acting antihypertensive drugs. 887 99

Dexfenfluramine increases serotonergic activity by stimulating serotonin (5-hydroxytryptamine; 5-HT) release into brain synapses, inhibiting its reuptake into presynaptic neurons and by directly stimulating postsynaptic serotonin receptors. On the basis of the serotonin hypothesis of appetite control, these actions would be expected to reduce appetite and, consequently, bodyweight. Studies conducted in animals and in overweight patients with and without associated disorders have confirmed the weight-reducing efficacy and good tolerability of dexfenfluramine. In 3-month clinical studies in obese patients, weight reductions with dexfenfluramine 15mg twice daily combined with dietary support were significantly higher than those achieved with placebo and similar to those with ephedrine/caffeine 20/20mg 3 times daily, sibutramine 10mg once daily and fluoxetine 60 mg/day. Furthermore, dexfenfluramine recipients with non-insulin-dependent diabetes mellitus, hyperlipidaemia or hypertension consistently show improvements in glycaemic control, blood lipid profiles and blood pressure. 12-month trial results indicate that most weight loss occurs in the initial 6 months and appears to be maintained for a further 6 months. Weight regain after withdrawal of treatment in 12-month studies demonstrates that dexfenfluramine is effective in maintaining a stable bodyweight at a lower level than placebo and in limiting food intake over this time period. Commonly reported adverse events with dexfenfluramine include diarrhoea, tiredness, dry mouth and somnolence; these symptoms are generally mild and transient. Approximately 7 and 10% of dexfenfluramine recipients in short and long term studies withdrew because of adverse events. Dexfenfluramine was better tolerated than ephedrine/caffeine and fluoxetine in short term studies. Obesity is a chronic condition that is accompanied by a number of metabolic complications. It is a significant health problem in developed countries, and as a major risk factor for many chronic diseases, including diabetes and cardiovascular disease, the economic burden of this condition is considerable. As with other chronic conditions, there is a role for pharmacological intervention in patients with severe obesity. However, drugs should be considered as only one component of a weight-control programme, since additional lifestyle modification is required to maintain weight loss. The promising data on the long term efficacy and tolerability of dexfenfluramine as well as its favourable effects on risk factors associated with obesity requires confirmation in long term studies. In the meantime, dexfenfluramine should be considered a valuable adjunct to a reduced-calorie diet in the management of severe obesity, particularly in patients with associated disorders and those unsuccessful with conventional weight loss measures. Available data support the use of the drug for up to 1 year to maintain weight loss and thus dexfenfluramine should be considered for long term administration.
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PMID:Dexfenfluramine. An updated review of its therapeutic use in the management of obesity. 911 19

Venlafaxine, a phenylethylamine, and nefazodone, a phenylpiperazine compound, are the newest antidepressants to receive approval of the Food and Drug Administration and to be marketed in the United States. Both strongly inhibit serotonin (5-HT) reuptake; venlafaxine also inhibits norepinephrine reuptake, and nefazodone also exhibits 5-HT2-receptor antagonism. Venlafaxine inhibits the cytochrome P-450 2D6 isozyme to a lesser extent than the selective serotonin reuptake inhibitors (SSRIs) and is 27% protein bound. Structurally, the drugs are unrelated to SSRIs and have some clinically important differences in side effect profiles. Nausea, headache, somnolence, and dry mouth are the most frequently reported side effects with both. Sustained hypertension was reported by a limited number of venlafaxine-treated patients.
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PMID:Venlafaxine and nefazodone, two pharmacologically distinct antidepressants. 916 54

Jimson weed (Datura stramonium, a member of the Belladonna alkyloid family) is a plant growing naturally in West Virginia and has been used as a home remedy since colonial times. Due to its easy availability and strong anticholinergic properties, teens are using Jimson weed as a drug. Plant parts can be brewed as a tea or chewed, and seed pods, commonly known as "pods" or "thorn apples," can be eaten. Side effects from ingesting jimson weed include tachycardia, dry mouth, dilated pupils, blurred vision, hallucinations, confusion, combative behavior, and difficulty urinating. Severe toxicity has been associated with coma and seizures, although death is rare. Treatment consists of activated charcoal and gastric lavage. Esmolol or other beta-blocker may be indicated to reduce severe sinus tachycardia. Seizures, severe hypertension, severe hallucinations, and life-threatening arrhythmias are indicators for the use of the anticholinesterase inhibitor, Physostigmine. This article reviews the cases of nine teenagers who were treated in hospitals in the Kanawha Valley after ingesting jimson weed. We hope this article will help alert primary care physicians about the abuse of jimson weed and inform health officials about the need to educate teens about the dangers of this plant.
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PMID:The dangers of jimson weed and its abuse by teenagers in the Kanawha Valley of West Virginia. 927 42

During the autumn of 1995, the National Poisons Information Centre was contacted about several cases of poisoning with Jimson weed (Datura stramonium). Five cases are described here. Upon admission to hospital the patients had moderate to severe anticholinergic symptoms, such as mydriasis, sinus tachycardia, agitation, dry mouth, urine retention, fever, hypertension, hallucinations and seizures. Owing to their agitated behaviour, gastrointestinal decontamination was impossible. Repeated doses of physostigmine (2-3 mg) administered intravenously reversed the anticholinergic features without side-effects. In the most severe case, physostigmine was needed for 18 hours (total dose; 25.5 mg). The patients recovered in a day or two, but mydriasis persisted in many cases.
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PMID:[Poisoning with Jimson weed. Five cases treated with physostigmine]. 932 14

Zolmitriptan (Zomig, formerly 311C90) at doses of 0.5-50 mg was administered to 316 unique volunteers in clinical pharmacology studies and 2,750 unique patients in eight clinical studies of acute migraine treatment. Overall, subjects received almost 50,000 doses; 97% of exposures were at doses > or = 2.5 mg. In the clinical pharmacology studies, the overall incidence of subject exposures experiencing at least one adverse event was 52% with zolmitriptan 2.5 mg (28% with placebo). In placebo-controlled studies, the overall incidence of patients with at least one adverse event was dose-dependent for zolmitriptan over the 1-15 mg dose range, e.g. 42% and 46% with 1 and 2.5 mg, respectively and 58% with 5 mg (29% with placebo). Only four serious adverse events attributable to zolmitriptan were reported. In a long-term study, during which 2,058 outpatients treated a total of 31,579 migraine attacks with either one or two zolmitriptan 5 mg doses over a period of up to 1 year, the number of attacks associated with at least one adverse event was similar after one (26%) and two (24%) doses. The majority (59%) of the adverse events reported in this study (59%) occurred within 2 h of dosing, were predominantly mild (59%) or moderate (35%) in intensity, of < or = 4 h duration (58%), required no further action (94%). In placebo-controlled studies, the percentage of patients who reported severe adverse events was similar with zolmitriptan 2.5 mg (4%) and placebo (5%). The most frequently reported adverse events with zolmitriptan in the placebo-controlled clinical studies were asthenia, heaviness (other than chest or neck), dry mouth, nausea, dizziness, somnolence, paresthesia and warm sensations. The type and severity of the adverse events was not influenced by gender (although the frequency of reported adverse events was higher in females, as was the case in the placebo group), age, presence of aura prior to the attack, association of migraine with menstruation, concurrent medication, or by the addition of a second zolmitriptan dose. Zolmitriptan showed a similar tolerability profile in the long-term study, in which a low withdrawal rate due to adverse events of 8% was observed. Zolmitriptan was not associated with an increased frequency of central nervous system-related adverse events in a comparative study of sumatriptan, despite pre-clinical and neurophysiological evidence of a dual peripheral and central action of zolmitriptan. Moreover, zolmitriptan doses of 5-20 mg produced no statistically significant effects on objective assessments of psychometric function. Zolmitriptan had no clinically significant effects on blood pressure (even in patients with controlled mild to moderate hypertension or impaired renal function), ECGs (e.g. there was no evidence of ischemic events) or clinical chemistry, hematological or urinalysis measurements. In summary, zolmitriptan is well tolerated, particularly at the recommended dose of 2.5 mg. Zolmitriptan has a well-defined dose-response with 2.5 mg proving highly effective and optimizing the benefit/risk ratio of treatment. Thus, zolmitriptan is well suited as an acute oral treatment for migraine in the outpatient setting.
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PMID:Tolerability profile of zolmitriptan (Zomig; 311C90), a novel dual central and peripherally acting 5HT1B/1D agonist. International clinical experience based on > 3000 subjects treated with zolmitriptan. 939 16

Classical centrally acting antihypertensive agents lower blood pressure by reducing excessive sympathetic tone; however, their clinical use is limited by an adverse effect profile resulting from alpha2-adrenoceptor agonism. Moxonidine is a new centrally acting agent showing selective agonism of imidazoline I1 receptors, but very little alpha2-adrenoceptor agonism. The safety and tolerability of moxonidine was reviewed over an 8-year period (1989 to 1997), including 74 clinical trials and an estimated 370000 patient-years of exposure. Dry mouth and somnolence were the most frequently reported adverse events, followed by headache and dizziness. In phase II to IV controlled studies in patients with hypertension (n = 1460), the incidence of dry mouth was 8 to 9%, somnolence 5 to 8% and headache 6%, as recorded by spontaneous reporting; the percentage of patients discontinuing treatment because of adverse events did not exceed 4%. Subgroup analyses revealed no differences in adverse events related to age or gender. Moxonidine did not exacerbate concomitant conditions such as diabetes mellitus or chronic obstructive pulmonary disease, or interact pharmacokinetically with concurrent medications such as hydrochlorothiazide, digoxin and glibenclamide (glyburide). Coadministration of moxonidine with lorazepam resulted in small additional impairments in tasks requiring attention. A similar distribution of adverse events was observed in uncontrolled studies (n = 1058). The incidence and severity of dry mouth and somnolence were found to decrease with increasing exposure to moxonidine over a period of up to 2 years. Serious adverse events were rare in all trials and could not be attributed to administration of moxonidine. Post-marketing surveillance of the adverse effect profile of moxonidine detected 2 additional adverse effects: nausea and allergic skin reactions. The safety profile of moxonidine, combined with proven antihypertensive efficacy, suggests that it may have an important role to play in the management of mild-to-moderate hypertension.
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PMID:Safety and tolerability of moxonidine in the treatment of hypertension. 974 66

The psychopharmacology of depression is a field that has evolved rapidly in just under 5 decades. Early antidepressant medications--tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs)--were discovered through astute clinical observations. These first-generation medications were effective because they enhanced serotonergic or noradrenergic mechanisms or both. Unfortunately, the TCAs also blocked histaminic, cholinergic, and alpha1-adrenergic receptor sites, and this action brought about unwanted side effects such as weight gain, dry mouth, constipation, drowsiness, and dizziness. MAOIs can interact with tyramine to cause potentially lethal hypertension and present potentially dangerous interactions with a number of medications and over-the-counter drugs. The newest generation of antidepressants, including the single-receptor selective serotonin reuptake inhibitors (SSRIs) and multiple-receptor antidepressants venlafaxine, mirtazapine, bupropion, trazodone, and nefazodone, target one or more specific brain receptor sites without, in most cases, activating unwanted sites such as histamine and acetylcholine. This paper discusses the new antidepressants, particularly with regard to mechanism of action, and looks at future developments in the treatment of depression.
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PMID:Mechanism of action of antidepressant medications. 1008 78

A double-blind, double-dummy, parallel-group trial that used a predominantly Hispanic patient population with mild-to-moderate hypertension was designed to compare the efficacy, safety, and acceptability of monotherapy with either transdermal clonidine applied once a week or terazosin tablets taken once a day. Of 44 patients admitted, 20 of 22 in the transdermal clonidine group and 15 of 21 in the terazosin group (one patient was lost to follow-up) met the response criteria. These criteria included the completion of 1 full week of therapy with the smallest dose that resulted in a seated diastolic blood pressure of <90 mm Hg and the subsequent entrance into an 8-week maintenance therapy phase. At the end of the 8-week maintenance phase the mean seated diastolic blood pressure remained <90 mm Hg in the clonidine cohort but not in the terazosin cohort, yet the difference was not statistically significant. There was a significantly better response to clonidine when all patients who received treatment were considered. No adverse first-dose effects were experienced with terazosin. One patient who received transdermal clonidine developed contact dermatitis and withdrew from the study prematurely. The most common side effects associated with clonidine were dry mouth and fatigue while those associated with terazosin were headache and fatigue. Compliance was excellent in both groups. Seventy-nine percent of patients found transdermal clonidine preferable to the oral regimen.
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PMID:Alpha 2-agonist versus alpha 1-antagonist in mild-to-moderate hypertension: comparison of transdermal clonidine and terazosin monotherapies. 1042 84


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