Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The chemistry, pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage of ticlopidine are reviewed. Ticlopidine appears to inhibit platelet aggregation induced by adenosine diphosphate. Ticlopidine hydrochloride is rapidly absorbed after oral administration, and maximum antiplatelet effects occur one to three hours after the dose. In multicenter, randomized, double-blind trials, ticlopidine was more effective than aspirin or placebo in preventing stroke, myocardial infarction, or death caused by vascular events. Ticlopidine was more effective than aspirin in preventing recurrent transient ischemic attacks after six months of therapy. Ticlopidine has also been used to prevent occlusion and improve patency of aortocoronary bypass grafts, to prevent ischemic ulcers in patients with chronic arterial occlusive disease, and to slow the progression of diabetic microangiopathy. The most serious adverse effect, neutropenia, occurred in about 1% of patients. The most frequently reported adverse effects are diarrhea, nausea, vomiting, and abdominal cramps. Ticlopidine is indicated for reducing the risk of thrombotic stroke in patients who have experienced a minor stroke, transient ischemic attack, or completed thrombotic stroke. The recommended dosage is 500 mg/day in two divided doses taken with food. Ticlopidine is an alternative agent for the primary and secondary prevention of stroke. Because of the risk of neutropenia and agranulocytosis and the high cost of therapy, ticlopidine should be reserved for patients who are intolerant of or lack benefit from aspirin.
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PMID:Ticlopidine: a new platelet aggregation inhibitor. 161 11

Enalapril is an effective agent in the treatment of mild to severe hypertension. It is equally effective in elderly and young adult patients but appears to be more effective in white than in black hypertensive patients. Following treatment with enalapril, an assessment of maximum exercise performance found a decrease in total peripheral resistance without significant changes in cardiac output, heart rate, or stroke volume compared with pretreatment values. In addition, there have been reports of reversal of left ventricular hypertrophy in enalapril-treated hypertensive patients. Enalapril is also effective and well tolerated in hypertensive patients with renal impairment of varying etiology. The most common adverse experiences reported in controlled clinical trials were headache (5.2%), dizziness (4.3%), and fatigue (3.0%). In high-risk hypertensive patients, no enalapril-treated neutropenia, proteinuria, dysgeusia, or ageusia were reported. It may be concluded that the benefit-to-risk ratio of enalapril is among the best of the antihypertensive therapies currently available.
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PMID:Enalapril: benefit-to-risk ratio in hypertensive patients. 169 15

Aspirin (acetylsalicylic acid) is effective in reducing vascular outcome events in patients with atherosclerosis: a relative risk reduction of about 30% for stroke, 22% for stroke and death, and 15% for vascular mortality. It is probable that low and high dose aspirin are similar in efficacy. Complications are more frequent with high dose aspirin than with low doses. Four randomised trials evaluating sulfinpyrazone vs placebo, and 3 trials evaluating sulfinpyrazone vs aspirin, showed more cerebrovascular events in the sulfinpyrazone group than in the aspirin and placebo groups. One small trial comparing dipyridamole with placebo in patients with cerebrovascular disease found no difference between the 2 groups in outcome. No other studies have compared dipyridamole alone with placebo or aspirin. The European Stroke Prevention Study II is currently in progress and is comparing dipyridamole + aspirin, dipyridamole, aspirin, and placebo. In the first year, the Ticlopidine Aspirin Stroke Study (TASS) showed a 42% risk reduction for stroke and death using the efficacy analysis and a 47% risk reduction for stroke and stroke death. Ticlopidine was more effective than aspirin in reducing stroke in both males and females. Apart from a reversible severe neutropenia in 0.86% of patients, ticlopidine-related adverse effects were relatively benign and reversible. The Canadian-American Ticlopidine Study (CATS) compared ticlopidine with placebo in patients with completed major strokes. The cumulative event rates for the primary outcome events of stroke, myocardial infarction and vascular death, using the efficacy approach, show clear evidence of separation almost immediately after randomisation, consistent with a constant risk reduction of about 30% in the ticlopidine group. These data provide strong evidence that ticlopidine conveys a clinically important reduction in the risk of thromboembolic events in patients with a history of completed thromboembolic stroke. In conclusion, aspirin is effective in preventing atherothrombotic morbidity and mortality. It reduces the overall vascular event rate by about 25%. Sulfinpyrazone and dipyridamole appear to add nothing important over aspirin alone. Ticlopidine is more effective than aspirin in preventing stroke. The modest, reversible risk of neutropenia, affecting less than 1% of patients, makes the benefit: risk ratio a reasonable one.
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PMID:Antiplatelet therapy in the prevention of stroke. 172 15

Ticlopidine is a new prototype antiplatelet drug chemically unrelated to currently available agents. It causes an alteration in platelet membrane reactivity to a variety of aggregating stimuli and a marked prolongation of bleeding time, the mechanism of which remains unclear. Two major phase III multicenter trials, the ticlopidine-aspirin stroke study (TASS) and the Canadian-American ticlopidine study (CATS) reported that the agent may reduce the occurrence of stroke, myocardial infarction, or vascular death in patients of both sexes who have had recent cerebral ischemia. Ticlopidine has been well tolerated in preliminary studies, with the most commonly described adverse effects being rash and gastrointestinal complaints. The most important adverse effect is neutropenia, which was reported in both TASS and CATS, approximating a frequency of 0.9% and 0.8%, respectively. Ticlopidine holds considerable promise as adjunctive therapy in selected patients.
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PMID:Ticlopidine: a new antiplatelet agent for cerebrovascular disease. 192 14

The role of white blood cells in acute central nervous system disorders, such as stroke or traumatic injury is poorly understood. In this experimental study the effect of neutropenia on posttraumatic brain oedema was investigated. Polyclonal antiserum against polymorphonuclear leukocytes was used to induce neutropenia. Control animals received normal serum or no treatment at all. Hemispheric swelling and brain water content after cryo-injury to the exposed left cerebral hemisphere was gravimetrically assessed, and by the wet weight-dry weight method. Administration of anti-neutrophil serum led to a significant reduction of circulating neutrophils. In untreated animals or in rats receiving normal serum, hemispheric swelling of the brain was 7.26 +/- 0.35% or 8.52 +/- 0.26%, respectively. Neutropenia induced by anti-neutrophil serum resulted in a significant increase in hemispheric swelling to 11.44 +/- 0.84% (p less than 0.001). It may be noted, however, that the enhancement of brain swelling by neutropenia was not obvious when comparing the water contents of the affected hemispheres of animals subjected to cold injury with and without anti-neutrophil serum. The enhancement of brain oedema by neutropenia suggests a protective function of neutrophils against extravasation in the presence of a broken blood-brain barrier.
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PMID:Effects of antineutrophil serum (ANS) on posttraumatic brain oedema in rats. 208 56

High dose intravenous gammaglobulin (0.4 g/kg/day) for five days, causes a rapid rise in the platelet count in immune thrombocytopenic purpura (ITP). The response in chronic ITP is transient making it useful in emergency situations. Efficacy in immune mediated neutropenia and warm antibody haemolytic anaemia has been reported but in limited numbers. We have used this therapy in twenty-three adults with ITP, one patient with immune neutropenia, four patients with warm antibody autoimmune haemolytic anaemia and one case of thrombotic thrombocytopenic purpura (TTP). In ITP only four of the twenty patients failed to respond to gammaglobulin and of these, three had a positive antinuclear factor but no other signs of systemic lupus erythematosis. The sole patient with neutropenia treated with IgG failed to show any response. In three patients with haemolytic anaemia parameters of haemolysis improved during therapy. The patient with TTP suffered a cerebrovascular accident during therapy prior to a documented response. High dose intravenous immunoglobulin rapidly elevates the platelet count in acute and chronic ITP. Its use in other immune mediated haematological conditions has yet to be fully evaluated.
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PMID:High dose intravenous gammaglobulin in immune haematological disease. 244 Jul 41

The Canadian American Ticlopidine Study (CATS) is a randomised, double-blind, placebo-controlled trial to assess the effect of ticlopidine (250 mg twice daily) in reducing the rate of subsequent occurrence of stroke, myocardial infarction, or vascular death in patients who have had a recent thromboembolic stroke. Twenty-five centres entered 1072 patients into the study between 1 week and 4 months after their qualifying stroke. The patients were treated and followed for up to 3 years (mean 24 months). In the efficacy analysis, the event rate per year for stroke, myocardial infarction or vascular death, considered together, was 15.3% in the placebo group and 10.8% in the ticlopidine group, representing a relative risk reduction with ticlopidine of 30.2% (95% confidence interval 7.5-48.3%; p = 0.006). Ticlopidine was beneficial for both men and women (relative risk reductions 28.1%, p = 0.037, and 34.2%, p = 0.045, respectively). Analysis by intention-to-treat gave a smaller estimate of risk reduction (23.3%, p = 0.020) for stroke, myocardial infarction, or vascular death. Adverse experiences associated with ticlopidine included neutropenia (severe in about 1% of cases) and skin rash and diarrhoea (severe in 2% of cases each); all were reversible. This study provides evidence of a beneficial effect of ticlopidine in both men and women with a recent thromboembolic stroke.
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PMID:The Canadian American Ticlopidine Study (CATS) in thromboembolic stroke. 256 17

We compared the cardiopulmonary responses to a single bolus (1.5 microgram/kg) vs. continuous infusion of endotoxin (LPS) (24 ng/kg/hr) in unanesthetized sheep. A single bolus produced an initial marked increase in pulmonary arterial pressure and plasma thromboxane levels and an elevated flow rate of lung lymph low in protein. Concomitantly, the cardiac output dropped and systemic vascular resistance rose. In the animals that received a continuous infusion of LPS, only very small changes in these variables were noted during this early period. Later, lung lymph flow rate and protein flux were elevated in both groups with a greater response in the bolus group. At 6 hr after LPS, the systemic vascular resistance fell in both groups, but to a greater extent in the bolus group, whereas the cardiac output rose to the same extent. Plasma levels of neutrophils, lymphocytes, and plasma prekallikrein levels decreased in both groups; neutropenia was more pronounced in the bolus group. The most important difference between both endotoxemia models during this phase was the reduction of the stroke work index in the bolus model, which was not observed with the continuous infusion. The apparent myocardial depression, the early reduction in cardiac output, and eicosanoid mediated pulmonary hypertension are the major differences between the two responses.
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PMID:Comparison of the cardiopulmonary responses to single bolus and continuous infusion of endotoxin in an ovine model. 265 Sep 14

Twenty-six episodes of Pseudomonas aeruginosa bacteremia treated with intravenous ceftazidime, 4-6 g/day were evaluated. Treatment was begun within the first 24 hours after the isolation of the microorganism and was maintained for 10-12 days. In two patients with neutropenia amikacin was added during the initial 48-72 hours until the susceptibility to ceftazidime was known. All isolates were sensitive to ceftazidime. The most common underlying diseases were neoplasia (12), diabetes with stroke (4), neurosurgical and vascular procedures (4), rheumatoid arthritis (2), burns (2), cor pulmonale (1), and hypertension (1). The origins of bacteremia were urinary (12), pulmonary (9), and unknown (5). The infection was hospital-acquired in 77% and community-acquired in 23%. A critical clinical status and the presence of complications were significantly (p less than 0.01) associated with an increased mortality rate. Clinical outcome was good in 18/26 (70%), with a 30% mortality rate. The microbiological evolution showed 14 eradications, 6 persistences, 3 relapses and 3 colonizations. Resistance did not develop during therapy. Ceftazidime may be a good alternative therapy for these severe infections, although wider comparative studies are required for a better evaluation.
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PMID:[Evaluation of ceftazidime monotherapy in Pseudomonas aeruginosa bacteremias. Prospective study]. 268 60

We report the results of the Ticlopidine Aspirin Stroke Study, a blinded trial at 56 North American centers that compared the effects of ticlopidine hydrochloride (500 mg daily) with those of aspirin (1300 mg daily) on the risk of stroke or death. The medications were randomly assigned to 3069 patients with recent transient or mild persistent focal cerebral or retinal ischemia. Follow-up lasted for two to six years. The three-year event rate for nonfatal stroke or death from any cause was 17 percent for ticlopidine and 19 percent for aspirin--a 12 percent risk reduction (95 percent confidence interval, -2 to 26 percent) with ticlopidine (P = 0.048 for cumulative Kaplan-Meier estimates). The rates of fatal and nonfatal stroke at three years were 10 percent for ticlopidine and 13 percent for aspirin--a 21 percent risk reduction (95 percent confidence interval, 4 to 38 percent) with ticlopidine (P = 0.024 for cumulative Kaplan-Meier estimates). Ticlopidine was more effective than aspirin in both sexes. The adverse effects of aspirin included diarrhea (10 percent), rash (5.5 percent), peptic ulceration (3 percent), gastritis (2 percent), and gastrointestinal bleeding (1 percent). With ticlopidine, diarrhea (20 percent), skin rash (14 percent), and severe but reversible neutropenia (less than 1 percent) were noted. The mean increase in total cholesterol level was 9 percent with ticlopidine and 2 percent with aspirin (P less than 0.01). The ratios of high-density lipoprotein and low-density lipoprotein to total cholesterol were similar in both treatment groups. We conclude that ticlopidine was somewhat more effective than aspirin in preventing strokes in this population, although the risks of side effects were greater.
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PMID:A randomized trial comparing ticlopidine hydrochloride with aspirin for the prevention of stroke in high-risk patients. Ticlopidine Aspirin Stroke Study Group. 230 95


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