Failure of acyclovir cream in treatment of recurrent herpes labialis.

A double blind, randomised, crossover placebo controlled trial of 5% acyclovir cream, applied topically five times a day for five days, was carried out in 45 patients with recurrent herpes labialis. These patients had a total of 72 episodes, 34 of which were treated with the 5% acyclovir cream and 38 with placebo cream. Treatment was begun by the patients as soon as possible after the onset of prodromal symptoms. There was no significant clinical benefit from treatment with acyclovir cream compared with placebo cream. The median healing times were nine days with acyclovir cream, 10 days with placebo cream, and 13 days when no treatment was given. The possibility that the 40% propylene glycol cream base alone has a therapeutic effect must therefore be considered.     

Balm mint extract (Lo-701) for topical treatment of recurring herpes labialis.

A double-blind, placebo-controlled, randomized trial was carried out with the aim of proving efficacy of standardized balm mint cream [active ingredient: 1% Lo-701--dried extract from Melissa officinalis L. leaves (70:1)] for the therapy of herpes simplex labialis. Sixty six patients with a history of recurrent herpes labialis (at least four episodes per year) in one center were treated topically; 34 of them with verum and 32 with placebo. The cream had to be smeared on the affected area four times daily over five days. A combined symptom score of the values for complaints, size of affected area and blisters at day 2 of therapy was formed as the primary target parameter. There was a significant difference in the values of the primary target parameter between both treatment groups: verum 4.03 +/- 0.33 (3.0); placebo 4.94 +/- 0.40 (5.0); values given are mean +/- SEM (median) of the symptoms score on day 2 of therapy. The tested formulation is effective for the treatment of herpes simplex labialis. The significant difference in the combined symptom score on the second day of treatment is of particular importance having in mind that the complaints in patients suffering from herpes labialis are usually most intensive at that time. In addition to the shortening of the healing period, the prevention of a spreading of the infection and the rapid effect on typical symptoms of herpes like itching, tingling, burning, stabbing, swelling, tautness and erythema, the balm mint cream has a further advantage. The different mechanism of action of the balm mint extract rules out the development of resistance of the herpes virus. Some indication exists that the intervals between the periods with herpes might be prolonged with balm mint cream treatment.     

Oral acyclovir in acute herpes zoster.

Oral acyclovir at a dose of 800 mg five times daily for seven days was compared with placebo in a randomised double blind trial conducted at three centres in the United Kingdom. The study group comprised 205 elderly immune competent patients suffering from herpes zoster who were entered within 72 hours of the onset of rash. Acyclovir significantly reduced the times to arrest of new lesion formation (p = 0.005), loss of vesicles (p less than 0.001), and full crusting (p = 0.02) in those patients entered within 48 hours of the onset of rash. In addition, there was a significant reduction in pain during treatment with acyclovir as compared with placebo (p = 0.008). Of the patients with severe pain on entry, 40% (10/25) of those treated with acyclovir had no or only mild pain at the end of treatment, whereas in the placebo group all had residual moderate or severe pain (p less than 0.001). No clinically important adverse effects of acyclovir were reported. Oral acyclovir may modify acute herpes zoster and reduce pain.     

Acyclovir given as prophylaxis against oral ulcers in acute myeloid leukaemia: randomised,double blind,placebo controlled trial.

OBJECTIVES--To evaluate (a) the prophylactic effect of the antiherpetic drug acyclovir on oral ulcers in patients with acute myeloid leukaemia receiving remission induction chemotherapy and thus (b), indirectly, the role of herpes simplex virus in the aetiology of these ulcers. DESIGN--Randomised, double blind, placebo controlled trial. SUBJECTS--74 herpes simplex virus seropositive patients aged 18-84. Thirty seven patients received acyclovir (800 mg by mouth daily) and 37 placebo. The patients were examined daily for 28 days. MAIN OUTCOME MEASURES--Occurrence of herpes labialis, intraoral ulcers, and acute necrotising ulcerative gingivitis. RESULTS--The two populations were comparable in age, sex, type of antineoplastic treatment, and history of herpes labialis. Acute oral infections occurred in 25 of the acyclovir treated patients and 36 of the placebo treated patients (relative risk 0.69 (95% confidence interval 0.55 to 0.87)). This difference was due to a reduction in the incidence of herpes labialis (one case versus eight cases; relative risk 0.13 (0.02 to 0.95)), intraoral ulcers excluding the soft palate (one case versus 13 cases; relative risk 0.08 (0.01 to 0.56)), and acute necrotising ulcerative gingivitis (one case versus eight cases; relative risk 0.13 (0.02 to 0.95)). However, ulcers on the soft palate were diagnosed with similar frequency in the two groups. Isolation of herpes simplex virus type 1 in saliva was reduced from 15 cases in the placebo group to one case in the acyclovir group (relative risk 0.07 (0.01 to 0.48)). CONCLUSION--Intraoral ulcers excluding the soft palate are most often due to infection with herpes simplex virus, whereas ulcers on the soft palate have a non-herpetic aetiology. The findings suggest that acute necrotising ulcerative gingivitis may also be due to herpes simplex virus. Prophylaxis with acyclovir should be considered for patients with acute myeloid leukaemia during remission induction therapy.     

A comparative multi-centre study of the efficacy of propolis, acyclovir and placebo in the treatment of genital herpes (HSV).

Ninety men and women with recurrent genital HSV type 2 participated in a randomized, single-blind, masked investigator, controlled multi-centre study comparing the efficacy of ointment of Canadian propolis containing natural flavonoids with ointments of acyclovir and placebo (vehicle) on healing ability and capacity to remedy symptoms. Thirty individuals were randomized to each group. Treatment was intended to start in the blister phase. All participants had HSV type 2 isolated, confirmed by serum immunoglobulin levels. The participants were examined on the 3rd, 7th and 10th days of treatment by gynaecologists, dermatovenerologists or urologists at seven different medical centres. Apart from clinical symptoms the number and size of the herpetic lesions were noted. At each examination the lesions were classified into four stages: vesicular, ulcerated, crusted and healed. The study ointments were applied to affected areas four times daily. In women with vaginal or cervical lesions a tampon with the appropriate ointment was inserted four times daily for 10 days. Endpoint variables were healing time and time until loss of symptoms. RESULTS: On Day 10, 24 out of 30 individuals in the propolis group had healed. In the acyclovir group 14 out of 30 and in the placebo group 12 out of 30 had healed. (p = 0.0015). The healing process appeared to be faster in the propolis group. In the propolis group 15 individuals had crusted lesions on Day 3 compared to 8 individuals in the acyclovir group and none in the placebo group (p = 0.0006). On Day 7, 10 participants in the propolis group, 4 in the acyclovir group and 3 in the placebo group had healed. At the initial examination all patients had local symptoms and 28% general symptoms. At Day 3, 3 patients in the propolis group had local symptoms compared to 8 and 9 in the acyclovir and placebo groups respectively. Of the women, 66% had vaginal superinfections of microbial pathogens at the initial examination. In the acyclovir and placebo groups no change in the vaginal flora was found following treatment whereas in the propolis group the incidence of superinfection was reduced by 55%. (p = 0.10 n.s.). CONCLUSION: An ointment containing flavonoids appeared to be more effective than both acyclovir and placebo ointments in healing genital herpetic lesions, and in reducing local symptoms.     

Effect of herbal therapy on herpes labialis and herpes genitalis

Administration of hot water extracts of six herbs to four patients with recurrent herpes labialis led to prompt crusting over and complete recovery within a few days. Similar treatment for one female patient who had been suffering from recurrent genital herpes resolved the associated pain dramatically. In all cases mentioned, symptoms disappeared much more quickly than with previous outbreaks when herb extracts were not administered.     

The efficacy and safety of solifenacin in patients with overactive bladder syndrome

The aim of the randomised, double blind, placebo controlled study was to evaluate the efficacy, tolerability and safety of solifenacin, a once-daily M3 selective receptor antagonist, in patients with overactive bladder syndrome. Following a single blind 2-week placebo run in period, patients who complained from symptoms of OAB for at least 6 months, were randomized to 4 weeks of solifenacin in 5 mg once daily doses or placebo. 171 patients were enrolled in the study and 157 patients completed the study. Patients with solifenacin had significantly improved micturitions per 24 hours after first week of treatment (1.75 +/- 0.63 vs. 2.64 +/- 0.48, p < 0.001), and after four weeks (1.56 +/- 0.58 vs. 2.71 +/- 0.45, p < 0.001) compared to placebo group. The mean number of urgency episodes per 24 hours had significantly decreased in patients with solifenacin compared to placebo after first week (5.75 +/- 1.43 vs. 6.65 +/- 0.65, p < 0.001), and after four weeks of treatment (5.77 +/- 1.33 vs. 6.54 +/- 0.50, p < 0.001). Solifenacin was also significantly more effective than placebo in reducing the mean number of episodes of severe urgency from baseline to end point (5.83 +/- 1.16 vs. 6.48 +/- 0.50, p < 0.001). Compared with changes obtained with placebo, episodes of urinary frequency were significanlty reduced after first week (0.3 vs. -0.5, p < 0.001) and four weeks check up periods in patients treated with solifenacin (0.19 vs. -0.15, p < 0.001). Episodes of nocturia was significantly reduced in patients treated with solifenacin after first week (0.3 vs. -0.5, p < 0.001), and after four weeks treatment period (0.45 vs. -0.50, p < 0.001). The number of incontinence episodes was also significantly decreased in solifenacin group compared to placebo group after first week (1.06 +/- 0.57 vs. 2.74 +/- 0.47, p < 0.001) and four weeks check up (0.96 +/- 0.57 vs. 2.75 +/- 0.43, p < 0.001). The most common adverse effects with solifenacin were dry mouth and constipation. Adverse effects were mild or moderate severity. The discontinuation rate owing to adverse effects was 4.5%-6.7% with solifenacin and 3.8%-6.1% with placebo, respectively. According to subjective estimation, significant improvement was achieved in 71 (92.21%) of patients treated with solifenacin and in 68 (85%) patients treated with placebo there was no change in OAB symptoms compared to baseline values. UDI score was significantly improved after solifenacin (22.26 +/- 5.91 vs. 29.61 +/- 8.45, p < 0.001) compared to placebo. IIQ score was significantly decreased in patients with solifenacin (36.25 +/- 10.34 vs. 46.86 +/- 6.81, p < 0.001) compared to placebo. In conclusion, solifenacin is a safe and effective treatment alternative for patients with overactive bladder symptoms.     

gamma Interferon production appears to predict time of recurrence of herpes labialis

Peripheral blood mononuclear cells separated from the blood of 29 volunteers within 3 wk of the onset of recurrent oral herpes labialis spontaneously secreted IFN-gamma (and small amounts of IFN-beta) into the culture medium in varying amounts (mean = 77 U/ml, SE = 17). However, interferon could not be detected in the serum of 10 of these patients tested. In the group as a whole, peak levels of interferon were secreted in vitro at 6 to 20 days after the onset of herpes labialis. Serial studies in eight patients showed peak production in the second or third week, with subsequent decrease to undetectable levels at 6 wk. A strong correlation between peak supernatant interferon level and the time to the next recurrence of herpes labialis in each patient was noted (r = 0.82, p less than 0.0001). Herpes simplex antigen-stimulated mononuclear cell cultures from each patient produced a mixture of IFN-alpha and IFN-gamma. A less marked but still significant correlation was noted between the peak mixed interferon level and the inter-recurrence interval (r = 0.52, p less than 0.005). These results suggest that a recurrent herpes labialis acts as an in vivo stimulus to the induction of IFN-gamma-producing cells that circulate in peripheral blood. The IFN-gamma produced is either a direct determinant of frequency of recurrence of herpes or a quantitative marker for other cellular immune events determining frequency.     

Successful treatment of experimental B virus (Herpesvirus simiae) infection with acyclovir.

The efficacy of the new nucleoside analogue acyclovir against B virus (Herpesvirus simiae) was investigated in rabbits and Vero cells infected with 2-136 and 0.3-1.0 TCD50 of the virus respectively. In the Vero cells 1 mg of acyclovir/1 reduced the yield of virus by 90%, which was slightly less than the effect on herpes simplex virus. Results in the rabbits varied with the interval between doses, duration of treatment, and delay before starting treatment. Acyclovir controlled an otherwise lethal infection when given not less than eight-hourly for 14 days. Withdrawing treatment after 9-10 days resulted in late-onset fatal disease in some rabbits. Treatment begun within 24 hours after infection gave complete protection, and rabbits first treated up to five days after infection showed a significant reduction in mortality (p less than 0.001). The plasma half life of acyclovir is twice as long in man as in rabbits and progression of the disease is much slower. Hence acyclovir may be useful for post-exposure prophylaxis against B virus infection in man and possibly also for treatment of the disease.     

The role of oral acyclovir in the management of genital herpes simplex.

Oral acyclovir is an antiviral nucleoside analogue that has recently been released in Canada for use in selected patients with genital infections by the herpes simplex virus. First episodes of genital herpes should be treated with oral acyclovir as soon as the diagnosis is considered. Most people with recurrent genital herpes do not require systemic drug therapy. Selected patients with severe or long-lasting recurrences, recurrences associated with long prodromal periods (greater than 12 to 24 hours) or systemic complications such as erythema multiforme and eczema herpeticum may receive measurable benefit from treatment at the onset of symptoms. In most patients frequently recurrent disease can be suppressed with long-term therapy. Since long-term safety beyond 1 year has not been established, suppressive therapy should be stopped at least once per year to reassess the recurrence pattern. Acyclovir has not been adequately tested for safety in pregnancy and should not be prescribed for pregnant women unless the potential benefits outweigh the risks. Careful attention to disease severity, accurate diagnosis and exclusion of other causes of genital lesions will ensure that the drug is used only when beneficial.     

Sustained release choline theophyllinate in nocturnal asthma.

Nocturnal wheeze is common in patients with asthma, and slow release theophyllines may reduce symptoms. As theophyllines are stimulants of the central nervous system the effect of 10 days'' twice daily treatment with sustained release choline theophyllinate or placebo on symptoms, overnight bronchoconstriction, nocturnal oxygen saturation, and quality of sleep were studied in a double blind crossover study in nine stable patients with nocturnal asthma (five men, four women, age range 23-64 years; forced expiratory volume in one second (FEV1) 0.85-3.8 1; vital capacity 1.95-6.1 1). When treated with the active drug all patients had plasma theophylline concentrations of at least 28 mmol/l (5 micrograms/ml) (peak plasma theophylline concentrations 50-144 mmol/l (9-26 micrograms/ml]. Morning FEV1 was higher when treated with sustained release choline theophyllinate (2.7 (SEM 0.3) 1) than placebo (2.1 (0.3) 1) (p less than 0.01). Both daytime and nocturnal symptoms were reduced when the patients were treated with sustained release choline theophyllinate and subjective quality of sleep was improved (p less than 0.002). When treated with the active drug, however, quality of sleep determined by electroencephalography deteriorated with an increase in wakefulness and drowsiness (p less than 0.05) and a reduction in non-rapid eye movement sleep (p less than 0.005). Treatment with choline theophyllinate had no effect on either the occurrence or the severity of transient nocturnal hypoxaemic episodes or apnoeas or hypopnoeas. In conclusion, sustained release choline theophyllinate prevents overnight bronchoconstriction, but impairs quality of sleep defined by electroencephalography.     

Efficacy and safety of foscarnet for recurrent orolabial herpes: a multicentre randomized double-blind study.

Foscarnet sodium (trisodium phosphonoformate hexahydrate) has been shown to inhibit herpes simplex virus (HSV) in vitro and to be efficacious for topical treatment of experimental HSV infection in animals. To assess its clinical efficacy in the treatment of recurrent orolabial herpes a multicentre collaborative, double-blind, placebo-controlled trial was conducted. The study patients were randomly assigned to receive either 3% foscarnet cream (78 patients) or placebo (cream vehicle) (75 patients) and were asked to start treatment at the earliest indication of a recurrence. Efficacy was evaluated in 143 patients (74 in the foscarnet group and 69 in the placebo group). There was no significant difference in time to healing or duration of virus shedding between the two groups. However, in the subgroup of patients who started treatment before vesicles appeared, the duration of virus shedding was shorter in the foscarnet group than in the placebo group (p = 0.04), and the proportion of lesions that evolved to the vesicular stage was smaller (p = 0.03). No significant difference in the incidence of local or systemic adverse effects was noted between the two groups. We conclude that the beneficial effect of foscarnet was limited to a subgroup of patients who started treatment in the prevesicular stage.     

Prevalence of recurrent herpes labialis and aphthous ulcers among young adults on six continents.

The prevalence of recurrent herpes labialis (RHL) and recurrent aphthous ulcers (RAU) in young adults - - 635 armed-forces recruits and 9897 health-profession students - - in 48 institutions in 21 countries was determined by a questionnaire survey. Two or more occurrences (lifetime prevalence) of RHL were reported by 33.2% of men and 28.0% of women; the corresponding figures for RAU were 38.7% and 49.7%. North American respondents, mainly from Canada, had a significantly higher prevalence of both lesions. There were some differences in relation to profession. Approximately 15% of all the people surveyed had had herpes labialis and 25% had had aphthous ulcers at least once during the previous year. Persons with a history of recurrence of one lesion were more likely to have a history of recurrence of the other.     

Twice weekly fluticasone propionate added to emollient maintenance treatment to reduce risk of relapse in atopic dermatitis: randomised,double blind,parallel group study

Objective To explore the efficacy and safety of fluticasone propionate, cream and ointment, applied twice weekly in addition to maintenance treatment with emollients, in reducing the risk of relapse of chronic recurrent atopic dermatitis.Design Randomised, double blind, parallel group study of 20 weeks'' duration.Setting Dermatology outpatient clinics (6 countries, 39 centres).Participants Adult (aged 12-65) patients with moderate to severe atopic dermatitis who were experiencing a flare.Methods Participants applied fluticasone propionate (0.05% cream or 0.005% ointment; once or twice daily) regularly for four weeks to stabilise their condition. The patients whose disease was brought under control then continued into a 16 week maintenance phase, applying emollient on a daily basis with a bath oil as needed and either the same formulation of fluticasone propionate or its placebo base (emollient alone) twice weekly to the areas that were usually affected.Main outcome measure Time to relapse of atopic dermatitis during maintenance phase.Results 376 patients entered the stabilisation phase, and 295 continued into the maintenance phase. After 16 weeks in the maintenance phase, the disease remained under control in 133 patients (87 using fluticasone propionate twice weekly, 46 using emollient alone), 135 (40 fluticasone propionate, 95 emollient) had experienced a relapse, and 27 had discontinued. Median time to relapse was six weeks for emollient alone compared with more than 16 weeks for additional fluticasone propionate. Patients who applied fluticasone propionate cream twice weekly were 5.8 times less likely (95% confidence interval 3.1 to 10.8, P < 0.001) and patients using fluticasone propionate ointment 1.9 times less likely (1.2 to 3.2, P=0.010) to have a relapse than patients applying emollient alone. The groups showed no differences in adverse events.Conclusion After atopic dermatitis had been stabilised the addition of fluticasone propionate twice weekly to maintenance treatment with emollients significantly reduced the risk of relapse.     

Controlled trial of propranolol to prevent recurrent variceal bleeding in patients with non-cirrhotic portal fibrosis.

Fifty patients with non-cirrhotic portal fibrosis who were admitted to hospital because of upper gastrointestinal bleeding were randomly assigned to treatment with either oral propranolol given in doses that reduced the resting pulse rate by 25% (25 patients) or with a placebo (25 patients). One year after the start of the study 20 patients in the propranolol group and five patients in the placebo group were free from recurrent gastrointestinal bleeding (p less than 0.0001). Giving continuous oral propranolol treatment is therefore effective in preventing recurrent upper gastrointestinal bleeding in patients with non-cirrhotic portal fibrosis.     

Role of nifedipine in treatment of hypertension.

The efficacy of nifedipine in the treatment of hypertension was assessed in 15 patients whose hypertension continued while being treated with atenolol 100 mg and bendrofluazide 5 mg daily. Nifedipine was added in doses of 10, 20, and 30 mg three times daily in a placebo controlled, double blind trial. One patient was withdrawn from the trial because of severe postural hypotension with the highest dose. Erect and supine blood pressure in the remaining 14 patients were significantly reduced by all doses of nifedipine. The drug was well tolerated but plasma potassium fell by 0.3 mmol(mEq)/1 during treatment (p less than 0.05). Nifedipine is thus effective in the treatment of hypertension but should probably be used in combination with a potassium sparing diuretic.     

Prevention of diabetic nephropathy with enalapril in normotensive diabetics with microalbuminuria.

STUDY OBJECTIVE--To assess the effectiveness of inhibition of angiotensin converting enzyme in preventing diabetic nephropathy. DESIGN--Randomised follow up study of normotensive diabetics with persistent microalbuminuria (30-300 mg/24 hours) treated with enalapril or its matched placebo for one year. Double blind for first six months, single blind for last six months. SETTING--Diabetic clinic in tertiary referral centre. PATIENTS--Treatment group and placebo group each comprised 10 normotensive diabetics with persistent microalbuminuria. INTERVENTIONS--Treatment group was given enalapril 20 mg daily and controls matched placebo. Patients were given antihypertensive treatment after one year. END POINT--Albumin excretion, arterial pressure, and renal function. MAIN RESULTS--In last three months of trial three of 10 patients taking placebo had diabetic nephropathy (albumin excretion greater than 300 mg/24 hours). No patients taking enalapril developed nephropathy and five showed normal albumin excretion (less than 30 mg/24 hours) (p = 0.005, Mann-Whitney test). Mean arterial pressure was reduced by enalapril throughout study (p less than 0.005) but increased linearly with placebo (p less than 0.05). Albumin excretion decreased linearly with enalapril but not placebo. An increase in albumin excretion with placebo was positively related to the increase in mean arterial pressure (r = 0.709, p less than 0.05, Spearman''s rank test). With enalapril total renal resistances and fractional albumin clearances improved progressively (time effect, p = 0.0001). CONCLUSION--Inhibition of angiotensin converting enzyme prevents development of nephropathy in normotensive diabetics with persistent microalbuminuria. This may be due to reduction in intraglomerular pressure and to prevention of increased systemic blood pressure. Future studies should compare long term effects of inhibitors of converting enzyme with other antihypertensive drugs.     

New polyprenyl phosphate based preparation Fortepren® as promising cytokine regulationg antiviral remedy

Fortepren^®, a product of the phosphorylation of polyprenols from fir needles (with sodium polyprenyl phosphate being the main active ingredient), belongs to the class of antiviral drugs with immunomodulating activity. Fortepren^® may be used as the drug of choice in the treatment of herpes diseases. It was shown that treatment with Fortepren^® of patients with a chronic recurrent herpes infection after acute phase termination with acyclovir decreased the recurrence rate, as well as the severity of local symptoms. Fortepren^® treatment of patients with a high incidence of recurrent herpes infection led to an increase in the interferon-producing ability of leucocytes stimulated with NDV, as well as in the production of key cytokines (IL-1β, IL-15, MIP-1α, IFN-γ, IL-12 (p40), TNF-α, IFN-α2, IL-12 (p70), IL-6) taking part in the protection against viral infection. Data suggest that the action of the drug is directed, first of all, to the cells responsible for the natural resistance of the organism (macrophages, dendritic cells, etc.). The activation of natural immunity appears to be a leading mechanism of protection from herpesviral infection under the influence of polyprenyl phosphate.     

Prevention of recurrent acute cystitis by methenamine hippurate: double blind controlled crossover long term study.

In a randomised, double blind, long term, crossover study 1 g twice daily of methenamine hippurate was compared with placebo for its preventive effect on recurrent attacks of acute cystitis. Methenamine hippurate and placebo were interchanged every six months for two years. During one of the years patients took 250 ml extra fluid every morning and evening. Out of 21 enrolled patients, 14 completed the first year and 13 both years of treatment, which permitted the evaluation of 27 patient years. There were 52 episodes of acute cystitis caused by reinfection: 41 occurred during placebo treatment and only 11 during the methenamine hippurate regimen (p less than 0.01). Extra fluid intake did not reduce the incidence of acute cystitis, nor did it reduce the effect of methenamine hippurate. Methenamine hippurate is an effective prophylactic agent against recurrent acute cystitis and has the advantage of not inducing cross resistance to conventional antibiotics.     

Intravenous prostacyclin (PGI2) infusion to 108 patients with ischaemic peripheral vascular disease: phase II-open study.

We recently reported the results of a double-blind trial of PGI2 in 108 patients with ischaemic peripheral vascular disease Stage II according to Fontaine. They were randomly allocated to receive an intravenous infusion of either PGI2 (6 ng/kg/min over 8 hours daily for 5 consecutive days) or placebo and classified as treatment responders or non-responders on the basis of changes in absolute and relative walking times. Patients treated with placebo and those who did not improve in this double blind trial entered an open trial in which they all received infusion of PGI2 (6 ng/kg/min over 8 hours daily for 5 consecutive days). The results of this open trial are reported here. Patients who had been allocated to PGI2 in the blind trial had significantly (p less than 0.01) longer walking times as compared to placebo-treated patients prior to receiving the second (PGI2) infusion. PGI2-infusion caused significant (p less than 0.01) prolongation of walking times in both groups up to the 2nd follow-up month. One month after infusion 52% (23 patients) of the initially placebo-treated patients and 31% (14 patients) of the initially PGI2-treated patients were scored as positive treatment responders (p less than 0.01).