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Erectile Dysfunction
Figure 1: Double-blind, Placebo-controlled Cross-over Prelox was more effective for men who presented with higher IIEF
Study with Prelox
scores at baseline than those with lower initial values. In this study a
further examination related to men’s sexual quality of life was carried
30
out. The authors found that the majority of men experienced an easier
25
initiation of erections during arousal and found it easier to sustain their
20
erections. Furthermore, 65% of the men reported increased morning
15
erections after taking Prelox for six weeks.
10
Mean IIEF score
AB AB AB AB AB
A double-blind, placebo-controlled, cross-over study with 50 men
5
further established the efficacy of Prelox for improvement of erectile
0
Run-in A = placebo Wash-out A = Prelox Wash-out quality.
14
Only men with a stable sexual partnership during the past six
B = Prelox B = placebo
months and with moderate ED corresponding to values ranging from
Figure 2: Six-month Double-blind, Placebo-controlled 11 to 17 on the erectile function domain of the IIEF score (questions
Study with 124 Men
1–5 and 15; score range 0–30) were recruited for this study. They had
no previous experience with PDE5 inhibitors and did not take any
p<0.05
30
p<0.05 prescribed medications during the trial period. These men presented
Prelox
with moderate cardiovascular risk factors related to bodyweight
25
(average body mass index [BMI] 26.05kgm
-2
) and blood pressure (BP)
20
(average systolic BP 133.5mmHg). Men were randomly assigned to one
Placebo
15 of two groups, A and B, with 25 men in each group. The two groups did
not significantly differ in terms of baseline IIEF scores and mean
10
Mean IIEF score
intercourse frequency (average 4.5 per month).
5
Figure 1 illustrates the chronology of the study protocol comprising the
0
036
five-month investigation period. During the first month (run-in period)
Treatment (months)
baseline IIEF scores were recorded. During the second month, group A
to 1.71g L-arginine. This enabled only two of the patients (5%) to regain was given placebo, while group B received four Prelox tablets, which
erectile function sufficient for sexual intercourse. During the following led to a substantial increase of IIEF scores. The third month served as
month all men continued the amino acid regimen, and additionally took a wash-out period, after which the IIEF scores in the previously Prelox-
80mg Pycnogenol per day. The success rate was dramatically treated group returned to almost baseline values. In the fourth month
increased, with 32 men (80%) regaining erectile function. For the group A was given Prelox, which led to significantly higher IIEF scores,
subsequent month, amino acid supplementation was maintained and while group B with placebo showed no effect. During the fifth month
120mg Pycnogenol a day was taken. The increased daily intake of no supplementation took place, and during this period the IIEF scores
Pycnogenol by 50% a day increased the number of men with restored in group A dropped to baseline values.
erectile function to 38 (92.5%). The outcome of the study clearly
suggests that the majority of the effect on men’s erectile function Following the treatment of respective groups with Prelox, men
resulted from the combination of Pycnogenol with L-arginine aspartate, reported a significantly increased frequency of morning erections
because the increased dosage of Pycnogenol by 50% yielded only a and easier initiation of and more sustained erections. Also, their
12.5% increased success rate. Furthermore, compared with the initial partners noted improved performance. Following the one-month
ED study with Pycnogenol only, which found significant improvement consumption of Prelox, the plasma testosterone level increased
only after three months, the combination of Pycnogenol with the amino significantly from 17.5 to 22.2nmol/l (p<0.02) in group A and from
acids resulted in significant effects after one month. It may be 18.1 to 22.0nmol/l (p<0.001) in group B. The investigators argued that
speculated that the further increase in the number of men with the increased testosterone level would be a secondary effect of
restored erectile function after treatment with a higher Pycnogenol-to- the increased intercourse frequency of patients, which is known
L-arginine ratio simply resulted from an additional month’s treatment to be associated with increasing testosterone.
20
Indeed, the mean
rather than reflecting any dose effects. intercourse frequency more than doubled during treatment from
4.4 to 10.7 and from 4.6 to 11.2 per month, respectively.
From the two exploratory studies, the Prelox formulation was
established to contain 20mg Pycnogenol and 700–750mg L-arginine Another double-blind, placebo-controlled Prelox product evaluation
aspartate. Compositions with higher dosages are not feasible because study was carried out in 124 men (average age 44 years) presenting
of technical (tablet size) limitations. with moderate ED.
21
Men in stable partnerships for at least six months
presenting with moderate ED were enrolled. Patients were randomly
Efficacy assigned to either four Prelox tablets (two in the morning, two in the
The efficacy of Prelox was validated in a clinical investigation in 40 evening) or corresponding placebo tablets over a period of six months.
men presenting with mild to moderate forms of ED who had no Fasting blood samples were taken at baseline and following
previous experience with PDE5 inhibitors.
19
A daily dosage of four completion of the trial for standard blood chemistry and rheology.
Prelox tablets was taken over a period of six weeks. Analysis of the
erectile function domain of the IIEF (questions 1–5 and 15) showed a Thirteen men dropped out due to non-medical reasons. In the Prelox
statistically significant increase from a baseline average of 22.1 to 24.5 group, the average IIEF score increased from a baseline of 15±6.6 to
after six weeks of taking Prelox. Closer examination showed that 25±2 after six months of treatment. The placebo group started with an
72 EUROPEAN ENDOCRINOLOGY