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Results for “randomized crossover trial”

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At least 379 records · Page 21Linked to original sources

PubMed1996

Fish oil supplementation in patients with heterozygous familial hypercholesterolemia.

Familial hypercholesterolemia is associated with premature coronary heart disease. In patients with familial hypercholesterolemia, monotherapy with hydroxymethylglutaril coenzyme. A reductase inhibitors rarely achieves the goal of desirable low-density lipoprotein levels. Epidemiological studies suggest that populations with a high dietary intake of marine n3 fatty acids are protected against coronary heart disease. Hepatic synthesis and secretion of very low density lipoproteins are reduced during fish oil supplementation while other effects on lipid and lipoprotein metabolism are controversial. Fourteen patients affected by familial heterozygous hypercholesterolemia on chronic treatment with simvastatin were enrolled in a double blind, placebo controlled, randomized crossover trial that evaluated the effect of fish oil ethyl ester (Esapent, 5.1 g/day) on lipid and lipoprotein serum concentrations. Total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglycerides, apoprotein B, apoprotein AI, lipoprotein (a) did not show any significant variation during the four week treatment period with fish oil ethyl ester. The present data suggest that the possible favourable influence of fish oil on the progression of atherosclerosis in these high-risk patients might involve mechanisms which are different from lipid metabolism.

Adult↗

PubMed1996

Efficacy and duration of salmeterol powder inhalation in protecting against exercise-induced bronchoconstriction.

BACKGROUND: The protective effect of a new long acting beta 2-agonist, salmeterol, against exercise-induced bronchoconstriction has been documented when given as inhaled aerosol. OBJECTIVE: The aim of the present study was to examine the duration of the protective effect of a single dose of salmeterol, 50 micrograms, inhaled as dry powder, against exercise-induced bronchoconstriction. METHODS: Sixteen patients with reproducible exercise-induced bronchoconstriction were challenged on a treadmill on two prestudy visits and six study days. The patients were challenged 4, 8, and 12 hours postdosing. The study was designed as a double blind placebo-controlled randomized crossover trial. RESULTS: Statistically significant differences in % maximum fall in PEFR were found at four and eight hours postdosing, in favor of salmeterol. At 12 hours postdosing, no clear statistical inference was possible, owing to the presence of a statistical carry-over effect; however, significant differences in area under curve in favor of salmeterol were found at 4, 8, and 12 hours postdosing. CONCLUSION: Salmeterol, 50 micrograms, dry powder inhalation had a protective effect against exercise-induced bronchoconstriction up to 12 hours postdosing, as compared with placebo. No adverse effects were identified.

Administration, Inhalation↗

PubMed1995

High-grade nucleoside transport inhibition stimulates ventilation in humans.

In 6 healthy male volunteers a placebo-controlled, double-blind, randomized, crossover trial was done to assess the effect of 1, 2, 4, and 6 mg of draflazine, a specific nucleoside transport inhibitor, on ventilation. Draflazine increased thoracic excursions dose-dependently by maximally (median with 95% confidence interval) 114.0% (38.3-184.8%) without affecting breathing rate. Ex vivo adenosine transport was inhibited by 0% (0-1%) after placebo, and 70% (59-74%), 81% (76-85%), 90% (86-93%), and 93% (90-96%) after the 4 increasing draflazine dosages, respectively (P < .05 for each draflazine dosage versus placebo). These results indicate that endogenously released adenosine may play a role in the regulation of ventilation.

Adenosine↗

PubMed1992

An antispasticity effect of threonine in multiple sclerosis.

To determine whether the naturally occurring amino acid threonine, a potential precursor for glycine biosynthesis in the spinal cord, has an effect on spasticity in multiple sclerosis, 26 ambulatory patients were entered into a randomized crossover trial. Threonine administered at a total daily dose of 7.5 g reduced signs of spasticity on clinical examination, although no symptomatic improvement could be detected by the examining physician or the patient. In contrast to the side effects of sedation and increased motor weakness associated with antispasticity drugs commonly used for the treatment of multiple sclerosis, no side effects or toxic effects of threonine were identified. Levels of threonine were elevated in serum and cerebrospinal fluid during treatment, but glycine levels did not change. Enhancement by threonine of glycinergic postsynaptic inhibition of the motor reflex arc in the spinal cord may represent a non-sedating, nontoxic approach to the management of spasticity in multiple sclerosis.

Adult↗

PubMed1979

Levodopa with benserazide or carbidopa in Parkinson disease.

Plasma levodopa and therapeutic responses to treatment with levodopa in combination with benserazide or carbidopa were studied in 49 patients with Parkinson disease not previously treated with levodopa in a blind randomized crossover trial. The treatment periods were 12 weeks; similar dosage schedules were used, with doses that induced equal levels of plasma levodopa in both combinations. In pretrial studies of plasma levodopa responses, 200 mg of levodopa and 50 mg of benserazide was equal to 250 mg of levodopa combined with 25 mg of carbidopa. Equal plasma levodopa responses to both combinations were also found during the trial. There was no significant difference between the treatment groups in beneficial effects on parkinsonian disability and individual symptoms or in the frequency of involuntary movements. However, nausea and vomiting occurred significantly more often during treatment with levodopa and carbidopa than during treatment with levodopa and benserazide. This difference was probably due to inadequate inhibition of peripheral decarboxylase inhibitor by the 1:10 ratio of carbidopa to levodopa.

Benserazide↗

PubMed1996

Circadian rhythms of prolactin and thyroid-stimulating hormone during the menstrual cycle and early versus late sleep deprivation in premenstrual dysphoric disorder.

The present study extended previous work by examining whether disturbances in the circadian rhythms of prolactin (PRL) and thyroid-stimulating hormone (TSH) distinguish patients with premenstrual dysphoric disorder (PMDD) from normal volunteers. In addition, the effects of therapeutic interventions with early and late partial sleep deprivation were explored. Both PRL and TSH levels were measured every 30 min from 18:00 h to 09:00 h during midfollicular and late luteal menstrual cycle phases in 23 PMDD patients and 18 normal volunteers. Hormone levels were measured again after a randomized crossover trial of early (sleep 03:00-07:00 h) versus late (sleep 21:00-01:00 h) partial sleep deprivation administered in two separate luteal phases. Compared with normal volunteers, PMDD patients had higher PRL concentrations, consistent with previous findings. TSH rhythms occurred earlier in PMDD than in normal subjects. PRL levels decreased and TSH levels increased with sleep deprivation compared with baseline conditions. The timing of PRL secretion shifted earlier with late sleep deprivation and later with early sleep deprivation. Although circadian disturbances of PRL and TSH were found in PMDD patients compared with normal volunteers, the therapeutic effects of early and late sleep deprivation do not appear to be mediated by correcting these disturbances.

Affect↗

PubMed1985

Lack of effect of oral activated charcoal on imipramine clearance.

The effect of oral activated charcoal on the pharmacokinetics of intravenous imipramine was studied in a randomized, crossover trial. Four normal men received intravenous imipramine (12.5 mg/70 kg) on two separate occasions, followed by either water or water plus high-surface-area activated charcoal (180 gm) in divided doses over 24 hours. Serum imipramine concentrations were measured from 0 to 24 hours after the imipramine infusion. There was no difference in the mean (+/- SE) t1/2 (9.0 +/- 0.8 vs. 10.9 +/- 1.6 hours), apparent volume of distribution (11.2 +/- 2.1 vs. 12.4 +/- 2.1 L/kg), or systemic clearance (992.2 +/- 138.3 vs. 930.3 +/- 101.9 ml/min/70 kg) of imipramine after dosing without and with oral activated charcoal, respectively (P greater than 0.05; paired t test). These results suggest that multiple oral doses of activated charcoal do not increase the clearance of imipramine in man.

Absorption↗

PubMed1988

Individual responses to converting enzyme inhibitors and calcium antagonists.

This study was designed to assess whether the acute blood pressure response of an individual hypertensive patient to a calcium antagonist or an angiotensin converting enzyme (ACE) inhibitor is a good predictor of the long-term efficacy of these drug classes in this particular patient. The concept that good responses to ACE inhibitors and calcium antagonists may be mutually exclusive was also tested. Sixteen patients were included in a randomized crossover trial of enalapril, 20 mg daily, and diltiazem, 120 mg daily, for 6 weeks each. Blood pressure was measured by ambulatory blood pressure recording. During the washout phase, the acute effect of nifedipine, 10 mg p.o., and enalaprilat, 5 mg i.v., was evaluated. Nifedipine and enalaprilat reduced blood pressure equally well. The long-term blood pressure reduction induced by enalapril and diltiazem was similar. The acute blood pressure response to a given drug was not a good predictor of the result obtained with long-term therapy. No age dependency of the antihypertensive effect of either drug class was apparent. There was no evidence that a good response to one drug excluded a similarly good response to the other.

Adult↗

PubMed1984

Effects of bepridil on exercise tolerance in chronic stable angina: a double-blind, randomized, placebo-controlled, crossover trial.

Bepridil, a calcium antagonist with a half-life of approximately 42 hours, was compared with placebo in a double-blind, randomized, crossover trial. Thirteen men (average age 62 years) with exercise-related angina pectoris and a positive exercise test (modified Bruce protocol) were studied. In the group as a whole, bepridil (400 mg once a day) caused an increased total exercise time (2.6 +/- 1.8 minutes, mean +/- standard deviation), time to onset of angina (3.3 +/- 1.6 minutes), time to 1 mm of ST-segment depression (2.2 +/- 2.3 minutes), time to 2 mm of ST-segment depression (2.4 +/- 1.4 minutes) and total work load achieved (1.8 +/- 1.4 kpm) compared with the preceding placebo phase (all p less than 0.05). Frequency of angina and nitroglycerin consumption were low and did not change significantly during bepridil therapy. Comparison of the 3 placebo periods (run-in, double-blind and washout) did not reveal a change in any measurement except time to onset of angina, suggesting no training effect or change in patient status. Adverse effects were common in patients taking both placebo and bepridil, but only 2 patients had adverse effects (dizziness) with bepridil that necessitated discontinuation of therapy. Similarity of the double product (systolic blood pressure X heart rate) at the end of exercise suggests a decrease in myocardial oxygen demand as the primary mode of action. This study suggests that bepridil is a promising agent for the treatment of exercise-induced myocardial ischemia.

Aged↗

PubMed1987

Comparison of four pancreatic extracts in cystic fibrosis.

Four different pancreatin products, Pancrease, Creon, Pancrex V Forte, and Pancreatin Merck, were compared in a random crossover trial in children with cystic fibrosis. The results of our study showed that patients who received Creon and Pancrease had fewer gastrointestinal symptoms than patients who received Pancrex V Forte and Pancreatin Merck. Fat absorption was significantly improved with Pancrease when compared with Pancrex V forte and Pancreatin Merck. Also the fat absorption with Creon was superior to that with Pancrex V Forte. There was no significant difference in fat absorption between Pancrease and Creon. Pancrex V Forte and Pancreatin Merck, or Pancreatin Merck and Creon. Faecal nitrogen content was less with both Creon and Pancrease compared with Pancreatin Merck. Creon and Pancrease allow the patient with cystic fibrosis to take a high energy diet without any dietary restrictions.

Adolescent↗

PubMed1993

Grapefruit juice--felodipine interaction: mechanism, predictability, and effect of naringin.

Grapefruit juice produces a marked and variable increase in felodipine bioavailability. The pharmacokinetics of felodipine and its single primary oxidative metabolite, dehydrofelodipine, were studied after drug administration with 200 ml water, grapefruit juice, or naringin in water at the same concentration as the juice in a randomized crossover trial of nine healthy men. With grapefruit juice, mean +/- SEM felodipine area under the plasma concentration-time curve (AUC) and peak plasma concentration (Cmax) were 206% +/- 23% (range, 123% to 330%, p < 0.01) and 170% +/- 24% (range, 127% to 310%, p < 0.02), respectively, compared with water. Dehydrofelodipine/felodipine ratios for AUC (1.5 +/- 0.2 versus 2.2 +/- 0.2, p < 0.001) and felodipine Cmax (1.5 +/- 0.2 versus 2.2 +/- 0.2, p < 0.001) were reduced, consistent with inhibition of presystemic felodipine metabolism. Intersubject changes in felodipine and dehydrofelodipine AUC supported inhibition of both primary and secondary metabolic steps as a mechanism. The interaction could not be predicted from baseline pharmacokinetics with water and did not result in more consistent bioavailability among individuals. Naringin solution produced much less of an interaction, showing that other factors were important.

Adult↗

PubMed1985

Aerosol beclomethasone in patients with steroid-responsive chronic obstructive pulmonary disease.

Some patients with chronic obstructive pulmonary disease have favorable responses to treatment with oral corticosteroids with increase in one-second forced expiratory volume of 30 percent or more above the baseline. The benefit of long-term steroid therapy may be outweighed by the side effects. Twelve patients who had previously demonstrated a response to oral corticosteroids were studied in a double-blind randomized crossover trial comparing prednisone (30 mg daily) with beclomethasone (metered-dose inhaler, 16 puffs daily) for two weeks each with a two-week washout period between the two regimens. Those who were taking prednisone tapered the dose to 5 mg daily and those taking beclomethasone discontinued it for two weeks before the beginning of the study. History, physical examination, and pulmonary function were monitored. The mean one-second forced expiratory volume increased from 0.65 to 1.00 liter after prednisone therapy and it increased from 0.63 to 0.81 liter after aerosol beclomethasone (difference significant, p less than 0.01 by paired t test). Only five of 12 patients had an increase in one-second forced expiratory volume with steroid aerosol, an increase that was at least 50 percent that achieved by prednisone. In most patients with steroid-responsive chronic obstructive pulmonary disease, aerosol beclomethasone is not an adequate substitute for oral steroids.

Administration, Oral↗

PubMedDate not supplied

Effect of reinforced laryngeal mask airway or endotracheal intubation anesthesia on adverse events: quality of life issues for dental patients requiring general sedation.

This study tested whether the use of a reinforced laryngeal mask airway (LMA) compared to endotracheal intubation (El) anesthesia diminished adverse events and improved the post-operative quality of life for 146 dental patients who required general anesthesia due to developmental disabilities. In this randomized, crossover trial, patients received either reinforced LMA or El anesthesia during an initial dental treatment visit; the other anesthetic method was used during a second visit scheduled after six months or more. Data were assessed with Student's t-test, chi-square test and McNemar's test to evaluate the affect on quality of life by analyzing disturbances in daily activity, such as eating patterns and sleeping behaviors after the procedure. Although the reinforced LMA anesthesia was associated with a significantly lowered incidence of adverse events (p = .04), neither method significantly disturbed quality of life activities.

Activities of Daily Living↗

PubMed1991

Interference of dairy products with the absorption of ciprofloxacin.

The effects of milk and yogurt on the bioavailability of ciprofloxacin were studied in seven healthy volunteers in a randomized crossover trial. After an overnight fast, 500 mg ciprofloxacin was given with 300 ml water, milk, or yogurt. Plasma ciprofloxacin concentrations were significantly (p less than 0.05) lower during the milk and yogurt phases from 1/2 to 10 hours; at 1/2 hour the concentration was reduced by 70% by milk and by 92% by yogurt. Milk reduced the peak plasma concentration by 36% (p less than 0.05) and yogurt by 47% (p less than 0.05). The extent of bioavailability, measured as the total area under the plasma concentration-time curve and 24-hour urinary excretion of ciprofloxacin, was reduced by 30% to 36% by milk and yogurt (p less than 0.05). We conclude that the absorption of ciprofloxacin can be reduced by concomitant ingestion of milk or yogurt. To avoid therapeutic failures in infections where the causative organism is only moderately susceptible, ingestion of large amounts of dairy products in liquid form with ciprofloxacin is not recommended.

Administration, Oral↗

PubMed1991

Protein-metabolism kinetics and energy-substrate utilization in infants fed parenteral solutions with different glucose-fat ratios.

The relative effect of glucose and lipids on whole-body protein-metabolism kinetics was assessed in seven infants undergoing parenteral feeding. Protein intake was kept constant and nonprotein energy was either provided as glucose alone or as an isoenergetic glucose-lipid mixture according to a randomized crossover trial. Protein metabolism and energy-substrate utilization were assessed by a primed, constant L-[13C]leucine infusion, combined with indirect calorimetry. There was a significant difference in the pattern of energy-substrate utilization according to regime. Protein turnover (11.3 +/- 0.7 vs 9.8 +/- 0.4 g.kg-1.d-1; P less than 0.05), protein breakdown (8.4 +/- 0.6 vs 7.1 +/- 0.4 g.kg-1.d-1; P less than 0.05), and amino acid oxidation rates (2.7 +/- 0.4 vs 1.4 +/- 0.5 g.kg-1.d-1; P less than 0.05) were higher for the glucose than the glucose-lipid treatment, whereas protein-synthesis rates did not significantly differ. These results suggest that the nature of energy substrates delivered to parenterally fed infants may affect protein metabolism.

Calorimetry, Indirect↗

PubMed2004

Supplementation of a diet low in carotenoids with tomato or carrot juice does not affect lipid peroxidation in plasma and feces of healthy men.

Antioxidant properties of carotenoids are thought to be at least partly responsible for the protective effects of fruits and vegetables rich in carotenoids against colon cancer. There are large amounts of in vitro data supporting this hypothesis. But there is little known about the antioxidant effects of carotenoid-rich food in vivo particularly in the gastrointestinal tract. In a randomized, crossover trial, healthy men (n = 22) who were consuming a low-carotenoid diet drank 330 mL/d tomato juice or carrot juice for 2 wk. Antioxidant capacity was assessed by the "lag time" of ex vivo LDL oxidation induced by copper and lipid peroxidation as determined by measurements of malondialdehyde (MDA) in plasma and feces using HPLC with fluorescence detection. Although consumption of both carotenoid-rich juices for 2 wk increased the carotenoid level in plasma and feces (P < 0.001), the antioxidant capacity of LDL tended to be increased by only approximately 4.5% (P = 0.08), and lipid peroxidation in the men's plasma and feces was not affected. Thus, processes other than lipid peroxidation could be responsible for the preventive effects of tomatoes and carrots against colon cancer.

Antioxidants↗

PubMed1988

More rapid relief of pain with isosorbide dinitrate oral spray than with sublingual tablets in elderly patients with angina pectoris.

To evaluate the possibility of improving clinical practice in the treatment of angina pectoris, the duration of relief of pain with isosorbide dinitrate (ISDN) oral spray and sublingual tablets were compared in elderly patients with chronic stable angina pectoris. Nine patients (mean age 67 years) were studied in a randomized crossover trial. The patients underwent bicycle ergometry, which resulted in typical chest pain associated with electrocardiographic ST-segment depression in all 9. The patients received ISDN oral spray or sublingual tablets immediately on termination of exercise. At least 6 hours later another ergometry test was performed and the patients were crossed over to the other drug. ISDN spray relieved pain in all patients at a mean duration of 61.6 +/- 24.4 seconds after administration, whereas the duration of relief of pain by ISDN sublingual tablets was 112.4 +/- 70 seconds. The difference was highly significant (p less than 0.0005). It is concluded that clinical practice of treatment of angina pectoris in the elderly can be improved by using ISDN oral spray rather than sublingual tablets. The spray is effective at twice the rapidity of the sublingual tablet.

Administration, Oral↗

PubMed1985

Treatment of progressive systemic sclerosis using factor XIII.

A double-blind, randomized crossover trial was carried out in 25 patients with progressive systemic sclerosis to compare the effectiveness and tolerability of treatment with Factor XIII with that of placebo. Patients received twice daily intravenous injections of either Factor XIII or placebo for 3 weeks and, after a wash-out period of 6 weeks, were crossed over to the alternative medication for a further 3 weeks. Assessments made by the physician and patients at the end of each treatment period indicated that Factor XIII was significantly better than placebo in improving the cutaneous manifestations of the disease and these opinions were supported by the significant improvement in the function index which was used to assess the degree of motor disability. Both local and general tolerability of Factor XIII treatment was good and there were no adverse reports.

Clinical Trials as Topic↗