A randomized trial of iloprost in patients with intermittent claudication. Treatment of intermittent claudication with beraprost sodium, an orally active prostaglandin I2 analogue: a double-blinded, randomized, controlled trial. A dose-effect study of beraprost sodium in intermittent claudication. Effects of taprostene, a chemically stable prostacyclin analogue, in patients with ischaemic peripheral vascular disease: a placebo controlled double-blind trial. The effects of prostaglandin E-1 in patients with intermittent claudication. Clinical effects of intravenous iloprost in patients with intermittent claudication. A double blind placebo controlled trial of intravenous prostacyclin (PGI2) in 108 patients with ischaemic peripheral vascular disease. Efficacy of a new prostaglandin E1 regimen in outpatients with severe intermittent claudication: results of a multicenter placebo-controlled double-blind trial. Effects of regular physical training in a supervised class and additional intravenous prostaglandin E1 and naftidrofuryl infusion therapy in patients with intermittent claudication--a controlled study. Intermittent intraarterial infusion therapy with PGE1 in patients with severe claudication--results of a randomized prospective double blind study. Clinical and haemorheological efficacy of i.a. PGE1 infusions in intermittent claudication. Randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of AS-013, a prostaglandin E1 prodrug, in patients with intermittent claudication. Intensive vascular training in stage IIb of peripheral arterial occlusive disease. The additive effects of intravenous prostaglandin E1 or intravenous pentoxifylline during training. Oral Beraprost sodium, a prostaglandin I(2) analogue, for intermittent claudication: a double-blind, randomized, multicenter controlled trial. Beraprost et Claudication Intermittente (BERCI) Research Group. Impact of a 4-week treatment with prostaglandin E1 on health-related quality of life of patients with intermittent claudication. Restoring vascular nitric oxide formation by L-arginine improves the symptoms of intermittent claudication in patients with peripheral arterial occlusive disease.
Prostanoids, which promote vasodilation and reduce platelet aggregation, have been proposed as candidate therapies for intermittent claudication due to peripheral arterial disease (PAD). However, studies of these medications have yielded inconsistent results. This study tested the hypothesis that iloprost, an oral prostacyclin analogue, would improve walking distance and quality of life in patients with intermittent claudication. The study was a multi-center, randomized, double-blind, placebo-controlled trial comparing three doses of oral iloprost (50 microg, 100 microg, or 150 microg twice daily), pentoxifylline, or placebo in 430 patients with intermittent claudication. The primary outcome measure was improvement in absolute claudication distance (ACD) after 6 months. Secondary outcomes included initial claudication distance and quality of life assessment. Placebo increased ACD by 3.3%, and iloprost increased peak ACD by 7.7%, 8.8% and 11.2% at the 50 microg, 100 microg, and 150 microg twice-daily doses, respectively (all insignificant relative to placebo). Pentoxifylline increased ACD by 13.9% relative to placebo (p = 0.039). Neither iloprost nor pentoxifylline enhanced quality of life. These results indicate that oral iloprost is not effective in improving exercise performance or quality of life in patients with PAD who have intermittent claudication. In the current study, we hypothesized that beraprost would: 1) improve treadmill exercise performance and quality of life; and 2) decrease rates of ischemic events in patients with intermittent claudication.
                Previous trials with beraprost sodium, an orally active prostaglandin I(2) analogue, in the treatment of claudication in patients with peripheral arterial disease (PAD) have been inconsistent.
                Patients with intermittent claudication (n = 897) were randomized to receive either 40 microg three times a day of beraprost with meals (n = 385) or placebo (n = 377) in a double-blinded manner for one year. The primary efficacy parameter was treadmill-measured maximum walking distance, as assessed at three and six months after randomization. Secondary efficacy parameters included treadmill-measured pain-free walking distance and change in quality of life.
                There was no significant improvement in maximum walking distance in the beraprost group (16.7%) as compared with the placebo group (14.6%, p = NS). Administration of beraprost did not improve the pain-free walking distance (p = NS between treatment groups), and there was no improvement in the quality-of-life measures between the treatment groups. The incidence of critical cardiovascular events was 7.3% in the beraprost group and 11.4% in the placebo group (p = NS). There was a significant reduction in the combination of cardiovascular death and myocardial infarction in the beraprost group (p = 0.01).
                Despite previous investigations suggesting efficacy, these results indicate that beraprost is not an effective treatment to improve symptoms of intermittent claudication in patients with PAD. The potential benefit of beraprost on critical cardiovascular events would require confirmation in a larger prospective investigation. We compared the efficacy and safety of three doses of beraprost sodium, an epoprostenol analogue, with placebo in the treatment of intermittent claudication (Fontaine's stage II). One hundred sixty-four patients were randomized to receive either placebo, 20 micrograms beraprost sodium (BPS60 group), 40 micrograms beraprost sodium (BPS120 group), or 60 micrograms beraprost sodium (BPS180 group) three times daily administered orally in a double-blind manner for 12 weeks. Treadmill exercise tests were performed twice during an initial selection phase (D-28 and D0) at week 10 (at trough beraprost concentration) and week 12 (at peak beraprost concentration) of the treatment phase. At week 10, all groups showed an increase in pain-free walking distance, and this distance was greatest in the BPS60 and BPS120 groups (p = 0.055). At week 12, a similar pattern was observed, and the difference was significant between the groups (p = 0.023). The most frequent adverse events reported were gastrointestinal disorders, headaches, skin disorders, and flushes. Patients who received either 60 or 120 micrograms of beraprost sodium daily had an increased pain-free walking distance. Further studies are required to investigate why the highest dose used (180 micrograms daily) showed lower efficacy. Having both vasodilating and antiplatelet properties and being able to increase pain-free walking distance in the short term, beraprost sodium is a promising drug for the treatment of intermittent claudication. Thirty patients with ischaemic peripheral vascular disease and intermittent claudication were randomly allocated to receive either placebo or taprostene, a chemically stable prostacyclin analogue, intravenously at a rate of 25 ng/kg/min for 6 hours daily on 5 consecutive days. Taprostene produced a significant (p less than 0.05) increase in absolute walking time compared to placebo on one day after infusion and at 1, 4 and 8 weeks (14% vs 2.8%) later. Taprostene also produced a significant (p less than 0.05) increase in the pain-free walking time compared to placebo in the follow-up period (8 weeks after infusion: 23% vs 3.8%). During the infusion period systolic and diastolic blood pressure decreased (p less than 0.05) and heart rate was accelerated (p less than 0.05) in the taprostene treated group whereas no change was monitored in the placebo group. The ankle/brachial Doppler index was unaffected by taprostene. The platelet half-life was significantly (p less than 0.05) prolonged following taprostene-infusion (72.6 +/- 9.35 vs 77.9 +/- 7.44 hours). However, no change on platelet half-life was found in the placebo group (p less than 0.05). Various measures of platelet function parameters followed in vitro (ADP-induced aggregation, platelet sensitivity to PGI2, PGE1, PGD1 and taprostene, concentrations of platelet factor 4 and beta-thromboglobulin) showed no change with taprostene. Measures of circulating platelet aggregates and endothelial cells count showed no changes during the 2 months follow-up period too. It is assumed that taprostene may be of clinical benefit in patients with ischaemic peripheral vascular disease. However, future investigations have to be carried out to assess the optimal dose regime. Aim of the study is to evaluate the effects of Prostaglandin E-1 (PGE-1) in patients with peripheral arterial disease (PAD) at the 2nd b stage Fontaine's classification. The study, controlled, single blinded, enrolled 123 patients with intermittent claudication that were randomised in two groups; the first group received a treatment with PGE-1 while the second one received a pentoxifylline-buflomedil association by venous infusion. We evaluated: Pain Free Walking Distance (PFWD), Maximum Walking Distance (MWD), Rest Flow (RF), Peak Flow (PF), Basal (BVR) and Minimal Vascular Resistance (MVR) with a strain gauge plethysmograph, Resting Flow (RF), Peak Flow (PF), time to reach the Peak Flow (tPF) and time to recovery of the base values (tRF) with laser Doppler flowmeter. After a four weeks treatment, we observed an increase of 370% about PFWD and of 260% in the MWD in patients treated with PGE-1; the other group showed an increase of 110% and 118% respectively. Moreover, the patients of the first group showed a significant increase regarding the plethysmographic Peak Flow (from 9.75+/-1.37 to 16.21+/-1.75, p<0.001), greater than the one observed in the second group (from 9.53+/-1.41 to 13.47+/-1.53, p<0.05); also the laser Doppler parameters showed a significant reduction, more evident in the first group (tPF from 23.0+/-7.5 to 10.5+/-4.9, p<0.001; tRF from 73.5+/-22.7 to 48.3+/-13.5, p<0.001) than in the second one. In a randomized patient-blind study iloprost or hydroxy-ethyl starch 200/0.5 were given i.v. 5 h daily for 2 weeks to 24 patients suffering from severe intermittent claudication due to peripheral vascular disease. An increase in pain-free walking distance of more than 50% occurred in 6 of 11 patients after the iloprost infusions and in 7 of 12 patients after HES treatment. No significant effects on haemodynamic or clinical chemistry tests were observed. 108 patients with ischemic peripheral vascular disease were randomly allocated to receive infusion of either PGI2 (6 ng/kg/min over 8 hours daily for 5 consecutive days) or placebo in a double-blind manner. All patients had Stage II disease (Fontaine classification). One month after infusion the absolute and relative walking times were significantly (p less than 0.05) longer in the PGI2- than in the placebo-treated group. Patients were further classified as treatment responders or non-responders on the basis of increase of absolute and relative walking times. After one month 44% (24 out of 54) of the PGI2- and 15% (8 out of 54) of the placebo-treated patients were positive treatment-responders (p less than 0.01). For the first time efficacy and safety of a new prostaglandin E1 (PGE1) regimen in the treatment of intermittent claudication were evaluated in a randomized, double-blind, placebo-controlled multicenter clinical trial. The study involved 213 outpatients with a maximum walking distance of 50 to 200 m measured on the treadmill (3 km/hr, 12% grade). After a 2-week run-in phase they received a 2-hour intravenous infusion of 60 micrograms PGE1 or placebo 5 days a week for 4 weeks. It was followed by a 4-week interval treatment with the same medication administered only twice a week. Patients were monitored for 3 months when they received no study medication. In the PGE1 group the intention-to-treat analysis (n = 208) revealed an increase in walking distance after 4 weeks of 75% (placebo, 43%). At the end of the interval treatment the walking distance had improved to 101% (placebo, 60%). The results remained virtually constant during follow-up (PGE1, 104%, placebo, 63%). Between-group comparisons showed significant differences in favor of PGE1 for all three time points of measurement (p < 0.05, p < 0.01, and p < 0.05). PGE1 was well tolerated; the rate of adverse reactions related to the treatment was 12.8% (placebo, 7.7%). In summary, these results show that the new PGE1 regimen is effective and safe in the treatment of outpatients with intermittent claudication. The aim of this study was to investigate if PGE1 i.v.-therapy after active physical training further increases the walking distance in PAOD stage IIb according to Fontaine. 48 outpatients with intermittent claudication underwent a standardized active walking training of about 6 months twice weekly. Afterwards patients were randomly given once daily an i.v. infusion of 60 micrograms PGE1 (3 ampoules prostavasin) or 600 mg naftidrofuryl. The therapy lasted for 3 weeks with the exception of Saturdays and Sundays. Besides laboratory and doppler parameters, painfree and maximum walking distance (treadmill, 10% incline, 3.5 km/h) were determined. Results: Under active physical training the patients' walking distance increased significantly to more than double the baseline levels. Further significant increase of the painfree walking distance was seen after a 3 week treatment with PGE1 from 136 to 270 m (99%) as well as with naftidrofuryl from 117 to 230 m (97%). While this difference was not significant there was a significant difference in favour to PGE1 after the follow-up period (p less than 0.01). In the PGE1-group the painfree walking distance showed a further increase (from 270m to 306m) whereas it decreased in the naftidrofuryl-group (from 230m to 210m). At the same time under PGE1 the ankle/arm index increased significantly in comparison to naftidrofuryl (p less than 0.01). Side effects differed significantly in respect of the frequency and severity. In the PGE1-group in 20.8% of the patients side effects occurred, whereas in 91.6% of the patients in the naftidrofuryl-group side effects were observed. In no case therapy had to be discontinued because of side effects. In a randomized prospective double blind study, intraarterial infusion therapy with prostaglandin E1 (PGE) was tested against infusion therapy with energy rich phosphates (ERP) in 40 patients with severe claudication. During the treatment period of three weeks, a significant increase of the painfree (PWD) and maximal walking distance (MWD) was observed. The improvement of PWD was of clinical relevance (PGE: 60----195 m; ERP: 69----170 m; p less than 0.001) and persisted during a 36 week post treatment observation period. The differences between the two drugs were not significant but showed a tendency in favour of the PGE therapy. nan Intermittent claudication due to peripheral arterial occlusive disease (PAOD) is a common cause of pain and disability in the middle-aged. Clinical trials of the potent vasodilator prostaglandin E1 have been disappointing. This is the first report of a controlled clinical trial of AS-0:3, a novel prodrug of prostaglandin E1 incorporated into lipid microspheres that has been developed to improve delivery of the active compound to blood vessel walls.
                Eighty patients with stenosis or occlusion, symptoms of intermittent claudication, and maximum walking distance of > or = 30 and < or = 300 m on a standard treadmill test were randomized to placebo or one of three dosage regimens of AS-013. Drug was administered by intravenous injection 5 d/wk for 4 weeks. Treadmill tests and other assessments were completed at weeks 0, 4, and 8. A statistically significant increase in maximum walking distance was observed at 4 weeks (for placebo: median, 4.5 m; interquartile range [IQR], 20; for active treatment: median, 28.0 m; IQR, 81; P < .01, Mann-Whitney test). A similar response was seen at 8 weeks (for placebo; median, -11.2 m; IQR, 35; for active treatment: median, 35 m; IQR, 68; P < .01, Mann-Whitney test). Dose-related improvements in pain-free walking distance and quality of life were observed. No serious safety issues were noted.
                These promising clinical data indicate that AS-013, a new prodrug of prostaglandin E1, could provide an effective and acceptable treatment for patients with intermittent claudication. Studies to investigate the optimal dosing regimen, duration of clinical benefit, and effects in more severe forms of peripheral arterial disease are warranted. In a randomized open study, the combination of either prostaglandin E1 (PGE1) or pentoxifylline with controlled vascular training was compared with vascular training alone in patients with peripheral arterial occlusive disease in stage IIb. Forty-four patients were randomly assigned to treatment either of intensive vascular training alone (n = 15) or in combination with either i.v. pentoxifylline (200 mg over 2 hours BID, n = 15) or PGE1 (40 micrograms over 2 hours BID, n = 14). The basic therapy was a well-defined routine for vascular training, which was identical for all groups. The duration of therapy was 4 weeks. In all three test groups, there was a significant increase in the walking distance. There was a 119% increase in symptom-free walking distance in the exercise-only group. In comparison with exercise alone, the additional administration of pentoxifylline produced no greater effect; the increase was 105%. In contrast, administration of PGE1 combined with exercise achieved a remarkable improvement of 604%. Between-group comparison revealed the significant superiority of treatment with PGE1 (P < .05). During the 1-year follow-up, there was a reduction in the walking performance in all groups, albeit of variable extent. In the exercise-only and the pentoxifylline groups, the maintained increase in walking distance was only 30% compared with baseline values before the beginning of therapy. In the PGE1 group, on the other hand, the maintained improvement was 149%. Nine of 14 patients were still in stage IIa of peripheral arterial occlusive disease 1 year after PGE1 therapy. Beraprost sodium (BPS) is a new stable, orally active prostaglandin I(2) analogue with antiplatelet and vasodilating properties. We report the results of a phase III clinical trial of BPS in patients with intermittent claudication.
                Patients (n=549) with a pain-free walking distance of between 50 and 300 m were entered into a 4-week single-blind placebo run-in phase. Patients whose pain-free walking distance had changed by <25% were then randomized to receive either BPS (40 microg TID, n=209) or placebo (n=213) in a double-blind manner for 6 months. Pain-free and maximum walking distances were measured on the occasion of treadmill exercise tests performed at baseline and 1.5, 3, 4.5, and 6 months after randomization. Success was defined as an improvement of >50% in pain-free walking distance at month 6 and in > or =1 earlier treadmill exercise test in the absence of critical cardiovascular events. Success was observed more frequently in the BPS group (43.5%) than in the placebo group (33.3%, P=0.036). Pain-free walking distances increased by 81.5% and 52.5%, respectively, in the BPS and placebo groups (P=0.001) and maximum walking distances by 60.1% and 35.0%, respectively (P=0.004). The incidence of critical cardiovascular events was 4.8% in the BPS group and 8.9% in the placebo group.
                These results show that BPS is an effective symptomatic treatment of patients with intermittent claudication. The beneficial effects of BPS on critical cardiovascular events should be confirmed in appropriate clinical trials. Intermittent claudication impairs functional status and quality of life in many patients by limiting walking capacity. The aim of this study was to evaluate the effects of a 4-week treatment with prostaglandin E1 (PGE1), a drug inducing vasodilation and inhibiting platelet aggregation, on improving functional status and health-related quality of life in patients with disabling intermittent claudication. Forty-two untrained outpatients (37 men and five women, mean age 64 +/- 8 years) with intermittent claudication,and maximum walking distance (MWD) of at least 50 and no more than 200 m on treadmill test (5% slope, 3 km/hr) were randomized to 4 weeks of double-blind treatment either with 60 mcg PGE1 daily given IV in 250 mL saline over a period of 2 hours (21 patients) or placebo (250 mL saline, 21 patients). Treatment-free follow-up was completed 8 weeks after the final infusion. Pain free walking distance (PFWD), MWD, and questionnaire evaluation were determined at baseline, after the 4-week treatment period, and at the end of the 8 weeks of the treatment-free follow-up period. After 4 weeks of treatment with PGE1 PFWD and MWD increased from 72 +/- 16 m to 135 +/- 33 m (+87%, p<0.001)and from 140 +/- 30 m to 266 +/- 62 m (+90%, p<0.001), respectively. Analysis of the Walking Impairment Questionnaire responses in the PGE1 group at 4 weeks demonstrated significant improvements in the walking impairment score (+19 percentage points, p<0.001), in the distance score (+25 percentage points, p<0.001), in the speed score (+24 percentage points, p<0.001), in the stair climbing score (+20 percentage points, p<0.001). The RAND survey responses showed improvements in physical function and bodily pain scores (+14 percentage points, p<0.001, and +15 percentage points, p<0.01, respectively). After the treatment-free follow-up period of 8 weeks, increases in PFWD and MWD were maintained (113 +/- 26 m, +57%, p<0.001, and 229 +/- 55 m, +63%, p<0.001, respectively). Similarly, at the end of the treatment-free follow-up, the walking impairment score (+16 percentage points, p<0.001), the distance score (+23 percentage points, p<0.001), the speed score (+22 percentage points, p<0.001), the stair climbing score (+18 percentage points, p<0.001) as well as the RAND physical function and bodily pain scores (+10 percentage points, p<0.001, and +13 percentage points, p<0.01, respectively) were still increased compared with baseline. No change from baseline was found in all the target parameters in the placebo group after 4 weeks of treatment and at the end of the treatment-free follow-up period. These data show that a 4-week treatment with PGE1 improves functional status and quality of life as well as treadmill performance in patients with disabling intermittent claudication as compared with placebo-treated patients. The improvements are also maintained for a period of 8 weeks beyond the end of the treatment. Additional studies are needed to determine the duration of functional benefits after the end of treatment. Administration of L-arginine improves nitric oxide (NO) formation and endothelium-dependent vasodilation in atherosclerotic patients.
                We investigated in this double-blind, controlled study whether prolonged intermittent infusion therapy with L-arginine improves the clinical symptoms of patients with intermittent claudication, as compared with the endothelium-independent vasodilator prostaglandin E1, and control patients.
                Thirty-nine patients with intermittent claudication were randomly assigned to receive 2 x 8 g L-arginine/day, or 2 x 40 microg prostaglandin E1 (PGE1)/day or no hemodynamically active treatment, for 3 weeks. The pain-free and absolute walking distances were assessed on a walking treadmill at 3 km/h, 12% slope, and NO-mediated, flow-induced vasodilation of the femoral artery was assessed by ultrasonography at baseline, at 1, 2 and 3 weeks of therapy and 6 weeks after the end of treatment. Urinary nitrate and cyclic guanosine-3', 5'-monophosphate (GMP) were assessed as indices of endogenous NO production.
                L-Arginine improved the pain-free walking distance by 230+/-63% and the absolute walking distance by 155+/-48% (each p < 0.05). Prostaglandin E1 improved both parameters by 209+/-63% and 144+/-28%, respectively (each p < 0.05), whereas control patients experienced no significant change. L-Arginine therapy also improved endothelium-dependent vasodilation in the femoral artery, whereas PGE1 had no such effect. There was a significant linear correlation between the L-arginine/asymmetric dimethylarginine (ADMA) ratio and the pain-free walking distance at baseline (r=0.359, p < 0.03). L-Arginine treatment elevated the plasma L-arginine/ADMA ratio and increased urinary nitrate and cyclic GMP excretion rates, indicating normalized endogenous NO formation. Prostaglandin E1 therapy had no significant effect on any of these parameters. Symptom scores assessed on a visual analog scale increased from 3.51+/-0.18 to 83+/-0.4 (L-arginine) and 7.0+/-0.5 (PGE1; each p < 0.05), but did not significantly change in the control group (4.3+/-0.4).
                Restoring NO formation and endothelium-dependent vasodilation by L-arginine improves the clinical symptoms of intermittent claudication in patients with peripheral arterial occlusive disease.
Whilst results from some individual studies suggested a beneficial effect of PGE1, the quality of these studies and of the overall evidence available is insufficient to determine whether or not patients with intermittent claudication derive clinically meaningful benefit from the administration of prostanoids. Further well-conducted randomised, double blinded trials with a sufficient number of participants to provide statistical power are required to answer this question.