CLINICAL PHARMACOLOGY
Mechanism Of Action
Penile erection is a hemodynamic
process initiated by the relaxation of smooth muscle in the corpus cavernosum
and its associated arterioles. During sexual stimulation, nitric oxide is
released from nerve endings and endothelial cells in the corpus cavernosum.
Nitric oxide activates the enzyme guanylate cyclase resulting in increased
synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells
of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation,
allowing increased blood flow into the penis, resulting in erection. The tissue
concentration of cGMP is regulated by both the rates of synthesis and
degradation via phosphodiesterases (PDEs). The most abundant PDE in the human
corpus cavernosum is the cGMP-specific PDE5; therefore, the inhibition of PDE5
enhances erectile function by increasing the amount of cGMP. Because sexual
stimulation is required to initiate the local release of nitric oxide, the
inhibition of PDE5 has no effect in the absence of sexual stimulation.
In vitro studies have shown that vardenafil is a selective inhibitor
of PDE5. The inhibitory effect of vardenafil is more selective on PDE5 than for
other known phosphodiesterases (>15-fold relative to PDE6, >130-fold
relative to PDE1, >300-fold relative to PDE11, and >1,000-fold relative
to PDE2, 3, 4, 7, 8, 9, and 10).
Pharmacodynamics
The pharmacodynamic studies
described below were conducted using vardenafil film-coated tablets.
Effects On Blood Pressure
In a clinical pharmacology
study of patients with erectile dysfunction, single doses of vardenafil 20 mg
film-coated tablets caused a mean maximum decrease in supine blood pressure of
7 mmHg systolic and 8 mmHg diastolic (compared to placebo), accompanied by a
mean maximum increase of heart rate of 4 beats per minute. The maximum decrease
in blood pressure occurred between 1 and 4 hours after dosing. Following
multiple dosing for 31 days, similar blood pressure responses were observed on
Day 31 as on Day 1. Vardenafil may add to the blood pressure lowering effects
of antihypertensive agents [see DRUG INTERACTIONS].
Effects On Blood Pressure And Heart
Rate When Vardenafil Is Combined With Nitrates
A study was conducted in which
the blood pressure and heart rate response to 0.4 mg nitroglycerin (NTG)
sublingually was evaluated in 18 healthy subjects following pretreatment with
vardenafil 20 mg film-coated tablets at various times before NTG
administration. Vardenafil 20 mg caused an additional time-related reduction in
blood pressure and increase in heart rate in association with NTG
administration. The blood pressure effects were observed when vardenafil 20 mg
was dosed 1 or 4 hours before NTG and the heart rate effects were observed when
20 mg was dosed 1, 4, or 8 hours before NTG. Additional blood pressure and
heart rate changes were not detected when vardenafil 20 mg film-coated tablet
was dosed 24 hours before NTG (see Figure 1).
Figure 1: Placebo-subtracted
point estimates (with 90% CI) of mean maximal blood pressure and heart rate
effects of pre-dosing with vardenafil 20 mg at 24, 8, 4, and 1 hour before 0.4
mg NTG sublingually
Because the disease state of
patients requiring nitrate therapy is anticipated to increase the likelihood of
hypotension, the use of vardenafil by patients on nitrate therapy or on nitric
oxide donors is contraindicated [see CONTRAINDICATIONS].
Blood Pressure Effects In Patients
On Stable Alpha-Blocker Treatment
Three clinical pharmacology
studies were conducted in patients with benign prostatic hyperplasia (BPH) on
stable-dose alpha-blocker treatment , consisting of alfuzosin, tamsulosin or
terazosin.
Study 1: This study was designed
to evaluate the effect of 5 mg vardenafil film-coated tablets compared to
placebo when administered to BPH patients on chronic alpha-blocker therapy in
two separate cohorts: tamsulosin 0.4 mg daily (cohort 1, n=21) and terazosin 5
or 10 mg daily (cohort 2, n=21). The design was a randomized, double blind,
cross-over study with four treatments: vardenafil 5 mg or placebo administered
simultaneously with the alpha-blocker and vardenafil 5 mg or placebo
administered 6 hours after the alpha-blocker. Blood pressure and pulse were
evaluated over the 6-hour interval after vardenafil dosing. For blood pressure
(BP) results, see Table 2. One patient, after simultaneous treatment with 5 mg
vardenafil and 10 mg terazosin, exhibited symptomatic hypotension with standing
blood pressure of 80/60 mmHg occurring one hour after administration and
subsequent mild dizziness and moderate lightheadedness lasting for 6 hours. For
vardenafil and placebo, five and two patients, respectively, experienced a
decrease in standing systolic blood pressure (SBP) of >30 mmHg following
simultaneous administration of terazosin. Hypotension was not observed when
vardenafil 5 mg and terazosin were administered 6 hours apart. Following
simultaneous administration of vardenafil 5 mg and tamsulosin, two patients had
a standing SBP of <85 mmHg. A decrease in standing SBP of >30 mmHg was
observed in two patients on tamsulosin receiving simultaneous vardenafil and in
one patient receiving simultaneous placebo treatment. When tamsulosin and
vardenafil 5 mg were separated by 6 hours, two patients had a standing SBP
<85 mmHg and one patient had a decrease in SBP of >30 mmHg. There were no
severe adverse events related to hypotension reported during the study. There
were no cases of syncope.
Table 2: Mean (95% CI)
maximal change from baseline in systolic blood pressure (mmHg) following
vardenafil 5 mg in BPH patients on stable alpha-blocker therapy (study 1)
Alpha-Blocker |
|
Simultaneous dosing of Vardenafil 5 mg and Alpha-Blocker, Placebo-Subtracted |
Dosing of Vardenafil 5 mg and Alpha-Blocker Separated by 6 Hours, Placebo-Subtracted |
Terazosin |
Standing SBP |
-3 (-6.7, 0.1) |
-4 (-7.4, -0.5) |
5 or 10 mg daily |
Supine SBP |
-4 (-6.7, -0.5) |
-4 (-7.1, -0.7) |
Tamsulosin |
Standing SBP |
-6 (-9.9, -2.1) |
-4 (-8.3, -0.5) |
0.4 mg daily |
Supine SBP |
-4 (-7, -0.8) |
-5 (-7.9, -1.7) |
Blood pressure effects standing SBP) in normotensive men on stable dose tamsulosin 0.4 mg following
simultaneous administration of vardenafil 5 mg or placebo, or following
administration of vardenafil 5 mg or placebo separated by 6 hours are shown in Figure
2. Blood pressure effects (standing SBP) in normotensive men on stable dose
terazosin (5 or 10 mg) following simultaneous administration of vardenafil 5 mg
or placebo, or following administration of vardenafil 5 mg or placebo separated
by 6 hours, are shown in Figure 3.
Figure 2: Mean change from
baseline in standing systolic blood pressure (mmHg) over 6 hour interval
following simultaneous or 6 hr separation administration of vardenafil 5 mg or
placebo with stable dose tamsulosin 0.4 mg in normotensive BPH patients (study
1)
Figure 3: Mean change from
baseline in standing systolic blood pressure (mmHg) over 6 hour interval
following simultaneous or 6 hr separation administration of vardenafil 5 mg or
placebo with stable dose terazosin (5 or 10 mg) in normotensive BPH patients
(study 1)
 |
Study 2: This study was designed
to evaluate the effect of 10 mg vardenafil (film-coated tablets) (stage 1) and
20 mg vardenafil (film-coated tablets) (stage 2) compared to placebo, when
administered to a single cohort of BPH patients (n=23) on stable therapy with
tamsulosin 0.4 mg or 0.8 mg daily for at least four weeks. The design was a
randomized, double blind, two-period, cross-over study. Vardenafil or placebo
was given simultaneously with tamsulosin. Blood pressure and pulse were
evaluated over the 6-hour interval after vardenafil dosing. For BP results see
Table 3. One patient experienced a decrease from baseline in standing SBP of
>30 mmHg following vardenafil 10 mg. There were no other instances of
outlier blood pressure values (standing SBP <85 mmHg or decrease from
baseline in standing SBP of >30 mmHg). Three patients reported dizziness
following vardenafil 20 mg. There were no cases of syncope.
Table 3: Mean (95% CI)
maximal change from baseline in systolic blood pressure (mmHg) following
vardenafil 10 and 20 mg (film-coated tablets) in BPH patients on stable
alpha-blocker therapy with tamsulosin 0.4 or 0.8 mg daily (study 2)
|
Vardenafil 10 mg Placebo- subtracted |
Vardenafil 20 mg Placebo- subtracted |
Standing SBP |
-4 (-6.8, -0.3) |
-4 (-6.8, -1.4) |
Supine SBP |
-5 (-8.2, -0.8) |
-4 (-6.3, -1.8) |
Blood pressure effects
(standing SBP) in normotensive men on stable dose of tamsulosin 0.4 mg following
simultaneous administration of vardenafil 10 mg, vardenafil 20 mg or placebo
are shown in Figure 4.
Figure 4: Mean change from
baseline in standing systolic blood pressure (mmHg) over 6 hour interval
following simultaneous administration of vardenafil 10 mg film-coated tablet
(stage 1), vardenafil 20 mg film-coated tablet (Stage 2), or placebo with
stable dose tamsulosin 0.4 mg in normotensive BPH patients (study 2)
Study 3: This study was
designed to evaluate the effect of single doses of 5 mg vardenafil (stage 1)
and 10 mg vardenafil (stage 2) compared to placebo, when administered to a
single cohort of BPH patients (n=24) on stable therapy with alfuzosin 10 mg
daily for at least four weeks. The design was a randomized, double blind,
3period cross-over study. Vardenafil or placebo was administered 4 hours after
the administration of alfuzosin. Blood pressure and pulse were evaluated over a
10-hour interval after dosing of vardenafil or placebo. For BP results see
Table 4.
Table 4: Mean (95% C.I.) maximal change from baseline
in systolic blood pressure (mmHg) following vardenafil 5 and 10 mg in BPH
patients on stable alpha-blocker therapy with alfuzosin 10 mg daily (Study 3)
|
Vardenafil 5 mg Placebo-subtracted |
Vardenafil 10 mg Placebo-subtracted |
Standing SBP |
-2 (-5.8, 1.2) |
-5 (-8.8, -1.6) |
Supine SBP |
-1 (-4.1, 2.1) |
-6 (-9.4, -2.8) |
One patient experienced decreases from baseline in
standing systolic blood pressure >30 mm Hg after administration of
vardenafil 5 mg film-coated tablets and vardenafil 10 mg film-coated tablets.
No instances of standing systolic blood pressure <85 mm Hg were observed
during this study. Four patients, one dosed with placebo, two dosed with
vardenafil 5 mg film-coated tablets and one dosed with vardenafil 10 mg
film-coated tablets, reported dizziness. Blood pressure effects (standing SBP)
in normotensive men on a stable dose of alfuzosin 10 mg following
administration of vardenafil 5 mg, vardenafil 10 mg, or placebo separated by 4
hours, are shown in Figure 5.
Figure 5: Mean change from baseline in standing
systolic blood pressure (mmHg) over 6 hour interval following 4 hr separation
administration of vardenafil 5 mg (stage 1), vardenafil 10 mg (stage 2) or
placebo with stable dose alfuzosin 10 mg in BPH patients (Study 3)
Blood Pressure Effects In Normotensive
Men After Forced Titration With Alpha-Blockers
Two randomized, double blind,
placebo-controlled clinical pharmacology studies with healthy normotensive
volunteers (age range, 45–74 years) were performed after forced titration of
the alpha-blocker terazosin to 10 mg daily over 14 days (n=29), and after
initiation of tamsulosin 0.4 mg daily for five days (n=24). There were no
severe adverse events related to hypotension in either study. Symptoms of
hypotension were a cause for withdrawal in 2 subjects receiving terazosin and
in 4 subjects receiving tamsulosin. Instances of outlier blood pressure values
(defined as standing SBP <85 mmHg and/or a decrease from baseline of
standing SBP >30 mmHg) were observed in 9/24 subjects receiving tamsulosin
and 19/29 receiving terazosin. The incidence of subjects with standing SBP
<85 mmHg given vardenafil and terazosin to achieve simultaneously the amount
of time at the maximum concentration in serum (Tmax) led to early termination
of that arm of the study. In most (7/8) of these subjects, instances of
standing SBP <85 mmHg were not associated with symptoms. Among subjects
treated with terazosin, outlier values were observed more frequently when
vardenafil and terazosin were given to achieve simultaneous Tmax than when
dosing was administered to separate Tmax by 6 hours. There were 3 cases of
dizziness observed with concomitant administration of terazosin and vardenafil.
Seven subjects experienced dizziness mainly occurring with simultaneous Tmax administration
of tamsulosin. There were no cases of syncope.
Table 5: Mean (95% CI)
maximal change in baseline in systolic blood pressure (mmHg) following
vardenafil 10 and 20 mg (film-coated tablets) in healthy volunteers on daily
alpha-blocker therapy
Alpha- Blocker |
|
Dosing of Vardenafil and Alpha-Blocker Separated by 6 Hours |
Simultaneous dosing of Vardenafil and Alpha-Blocker |
Vardenafil 10 mg Placebo- Subtracted |
Vardenafil 20 mg Placebo- Subtracted |
Vardenafil 10 mg Placebo- Subtracted |
Vardenafil 20 mg Placebo- Subtracted |
Terazosin 10 mg daily |
Standing SBP |
-7
(-10, -3) |
-11
(-14, -7) |
-23
(-31, 16)* |
-14
(-33, 11)* |
Supine SBP |
-5
(-8, -2) |
-7
(-11, -4) |
-7
(-25, 19)* |
-7
(-31, 22)* |
Tamsulosin 0.4 mg daily |
Standing SBP |
-4
(-8, -1) |
-8
(-11, -4) |
-8
(-14, -2) |
-8
(-14, -1) |
Supine SBP |
-4
(-8, 0) |
-7
(-11, -3) |
-5
(-9, -2) |
-3
(-7, 0) |
* Due to the sample size,
confidence intervals may not be an accurate measure for these data. These
values represent the range for the difference. |
Figure 6: Mean change from
baseline in standing systolic blood pressure (mmHg) over 6 hour interval
following simultaneous or 6 hr separation administration of vardenafil 10 mg
and 20 mg (film-coated tablets) or placebo with terazosin (10 mg) in healthy
volunteers
Figure 7: Mean change from
baseline in standing systolic blood pressure (mmHg) over 6 hour interval
following simultaneous or 6 hr separation administration of vardenafil 10 mg
and 20 mg (film-coated tablets) or placebo with tamsulosin (0.4 mg) in healthy
volunteers
Effects On Cardiac
Electrophysiology
The effect of 10 mg and 80 mg
vardenafil, administered as film-coated tablets, on QT interval was evaluated
in a single-dose, double-blind, randomized, placebo-and active-controlled
(moxifloxacin 400 mg) crossover study in 59 healthy males (81% White, 12%
Black, 7% Hispanic) aged 45–60 years. The QT interval was measured at one hour
post dose because this time point approximates the average time of peak
vardenafil concentration. The 80 mg dose of vardenafil (four times the highest
recommended dose of the film-coated tablets) was chosen because this dose
yields plasma concentrations covering those observed upon co-administration of
a low-dose of vardenafil (5 mg) and 600 mg b.i.d. of ritonavir. Of the CYP3A4
inhibitors that have been studied, ritonavir causes the most significant
drug-drug interaction with vardenafil. Table 6 summarizes the effect on mean
uncorrected QT and mean corrected QT interval (QTc) with different methods of
correction (Fridericia and a linear individual correction method) at one hour
post-dose. No single correction method is known to be more valid than the
other. In this study, the mean increase in heart rate associated with a 10 mg
dose of vardenafil, administered as a film-coated tablet, compared to placebo
was 5 beats/minute and with an 80 mg dose of vardenafil the mean increase was 6
beats/minute.
Table 6: Mean QT and QTc
changes in msec (90% CI) from baseline relative to placebo at 1 hour post-dose
with different methodologies to correct for the effect of heart rate
Drug/Dose |
QT Uncorrected (msec) |
Fridericia QT Correction (msec) |
Individual QT Correction (msec) |
Vardenafil 10 mg |
-2 (-4, 0) |
8 (6, 9) |
4 (3, 6) |
Vardenafil 80 mg |
-2 (-4, 0) |
10 (8, 11) |
6 (4, 7) |
Moxifloxacin* 400 mg |
3 (1, 5) |
8 (6 9) |
7 (5, 8) |
* Active control (drug known to prolong QT) |
Therapeutic and supratherapeutic doses of vardenafil and the active control moxifloxacin
produced similar increases in QTc interval. This study, however, was not
designed to make direct statistical comparisons between the drugs or the dose
levels. The clinical impact of these QTc changes is unknown [see WARNINGS
AND PRECAUTIONS].
In a separate postmarketing
study of 44 healthy volunteers, single doses of 10 mg vardenafil (film-coated
tablet) resulted in a placebo-subtracted mean change from baseline of QTcF
(Fridericia correction) of 5 msec (90% CI: 2,8). Single doses of gatifloxacin
400 mg resulted in a placebo-subtracted mean change from baseline QTcF of 4
msec (90% CI: 1,7). When vardenafil 10mg (film-coated tablets) and gatifloxacin
400 mg were co-administered, the mean QTcF change from baseline was additive
when compared to either drug alone and produced a mean QTcF change of 9 msec
from baseline (90% CI: 6,11). The clinical impact of these QT changes is
unknown [see WARNINGS AND PRECAUTIONS].
Effects On Exercise Treadmill
Test In Patients With Coronary Artery Disease (CAD)
In two independent trials that
assessed 10 mg (n=41) and 20 mg (n=39) vardenafil (film-coated tablets),
respectively, vardenafil did not alter the total treadmill exercise time
compared to placebo. The patient population included men aged 40–80 years with stable
exercise-induced angina documented by at least one of the following: 1) prior
history of myocardial infarction (MI), coronary artery bypass graft (CABG),
percutaneous transluminal coronary angioplasty (PTCA), or stenting (not within
6 months); 2) positive coronary angiogram showing at least 60% narrowing of the
diameter of at least one major coronary artery; or 3) a positive stress
echocardiogram or stress nuclear perfusion study.
Results of these studies showed
that vardenafil did not alter the total treadmill exercise time compared to
placebo (vardenafil 10 mg vs. placebo: 433±109 and 426±105 seconds,
respectively; 20 mg vardenafil vs. placebo: 414±114 and 411±124 seconds,
respectively). The total time to angina was not altered by vardenafil when compared
to placebo (10 mg vardenafil vs. placebo: 291±123 and 292±110 seconds; 20 mg
vardenafil vs. placebo: 354±137 and 347±143 seconds, respectively). The total
time to 1 mm or greater ST-segment depression was similar to placebo in both
the 10 mg and the 20 mg vardenafil groups (10 mg vardenafil vs. placebo:
380±108 and 334±108 seconds; 20 mg vardenafil vs. placebo: 364±101 and 366±105
seconds, respectively).
Effects On Eye
Single oral doses of
phosphodiesterase inhibitors have demonstrated transient dose-related
impairment of color discrimination (blue/green) using the Farnsworth-Munsell
100-hue (FM-100) test and reductions in electroretinogram (ERG) b-wave
amplitudes, with peak effects near the time of peak plasma levels. These
findings are consistent with the inhibition of PDE6 in rods and cones, which is
involved in phototransduction in the retina. The findings were most evident one
hour after administration, diminishing but still present 6 hours after
administration. In a single dose study in 25 normal males, vardenafil
(film-coated tablets) 40 mg, twice the maximum daily recommended dose, did not
alter visual acuity, intraocular pressure, fundoscopic and slit lamp findings.
In another double-blind,
placebo-controlled clinical trial, at least 15 doses of 20 mg vardenafil were
administered over 8 weeks versus placebo to 52 males. Thirty-two (32) males
(62% of the patients) completed the trial. Retinal function was measured by ERG
and FM-100 test 2, 6 and 24 hours after dosing. The trial was designed to
detect changes in retinal function that might occur in more than 10% of
patients. Vardenafil did not produce clinically significant ERG or FM-100
effects in healthy men compared to placebo. Two patients on vardenafil in the
trial reported episodes of transient cyanopsia (objects appear blue).
Effects On Sperm Motility
Morphology
There was no effect on sperm
motility or morphology after single 20 mg oral doses of vardenafil film-coated
tablets in healthy volunteers.
Pharmacokinetics
The pharmacokinetics of
vardenafil and its M1 metabolite from STAXYN have been evaluated in healthy
male volunteers (18–50 years) and in young (18–45 years) and elderly (≥
65 years) erectile dysfunction patients. Studies have shown that STAXYN
provides higher systemic exposure of vardenafil compared to vardenafil 10 mg
film-coated tablets.
Absorption
Mean vardenafil plasma
concentrations measured after the administration of a single oral dose STAXYN
to patients with erectile dysfunction (18-45 years) are depicted in Figure 8.
Figure 8: Vardenafil Plasma Concentration (Mean ± SD)
Profile for STAXYN in men age 18–45 years with erectile dysfunction
The median time to reach Cmax (Tmax)
in patients receiving STAXYN in the fasted state was 1.5 h [range: 0.75 – 2.5
h]. After administration of STAXYN to elderly (≥ 65 years) and young
(18–45 years) patients with erectile dysfunction, mean vardenafil AUC was
increased by 21 to 29%, respectively while mean Cmax was lower by 19% and 8%,
respectively, in comparison to 10 mg vardenafil (film-coated tablets). In a
study of healthy male volunteers (18–50 years), the mean Cmax and AUC of
vardenafil from STAXYN were higher by 15% and 44%, respectively compared to 10
mg vardenafil film-coated tablets.
Vardenafil was not found to
accumulate in plasma when STAXYN was dosed daily over ten days.
Effect Of Food
A high fat meal had no effect
on vardenafil AUC and Tmax from STAXYN in healthy volunteers and reduced Cmax by
35%. Clinical trials for STAXYN were conducted without regard to meals. STAXYN
can be taken with or without food.
Effect Of Water
When STAXYN was swallowed with
water, the AUC of vardenafil was reduced by 29% and median Tmax was shortened
by 60 minutes while Cmax was not affected. In clinical trials, dosing was done
without water. STAXYN should be taken without liquid.
Distribution
The mean steady-state volume of
distribution (Vss) for vardenafil is 208 L, indicating extensive tissue
distribution. Vardenafil and its major circulating metabolite, M1, are highly
bound to plasma proteins (about 95% for parent drug and M1). This protein
binding is reversible and independent of total drug concentrations.
Following a single oral dose of
20 mg vardenafil film-coated tablet in healthy volunteers, a mean of 0.00018%
of the administered dose was obtained in semen 1.5 hours after dosing.
Metabolism
Vardenafil is metabolized
predominantly by the hepatic enzyme CYP3A4, with contribution from the CYP3A5
and CYP2C isoforms. The major circulating metabolite, M1, results from
desethylation at the piperazine moiety of vardenafil. M1 is subject to further
metabolism. The plasma concentration of M1 is approximately 26% that of the
parent compound. This metabolite shows a phosphodiesterase selectivity profile
similar to that of vardenafil and an in vitro inhibitory potency for PDE5 28%
of that of vardenafil. Therefore, M1 accounts for approximately 7% of total
pharmacologic activity.
Excretion
The mean terminal half-life of vardenafil in patients
receiving STAXYN tablets varied between about 4–6 hours. The elimination
half-life of the metabolite M1 is between 3 to 5 hours. After oral
administration, vardenafil is excreted as metabolites predominantly in the
feces (approximately 91–95% of administered oral dose) and to a lesser extent
in the urine (approximately 2–6% of administered oral dose). Vardenafil is a
high clearance drug with a plasma clearance of 56.4 L/h following intravenous
administration.
Pharmacokinetics In Specific Populations
Pediatrics
STAXYN is not indicated for use in pediatric patients.
Vardenafil trials were not conducted in the pediatric population.
Geriatrics
Vardenafil AUC and Cmax in elderly patients (65 years or
older) taking STAXYN were increased by 39% and 21%, respectively, in comparison
to patients aged 45 years and below [see Use In Specific Populations].
Hepatic Impairment
In volunteers with mild hepatic impairment (Child-Pugh
A), the Cmax and AUC following a 10 mg vardenafil (film-coated tablets) dose
were increased by 22% and 17%, respectively, compared to healthy control
subjects. In volunteers with moderate hepatic impairment (Child-Pugh B), the Cmax
and AUC following a 10 mg vardenafil (film-coated tablets) dose were increased
by 130% and 160%, respectively, compared to healthy control subjects.
Vardenafil has not been evaluated in patients with severe (Child-Pugh C)
hepatic impairment. [See DOSAGE AND ADMINISTRATION, WARNINGS AND
PRECAUTIONS, and Use In Specific Populations]
Renal Impairment
In volunteers with mild renal impairment (CLcr = 50–80
mL/min), the pharmacokinetics of vardenafil were similar to those observed in a
control group with normal renal function. In the moderate (CLcr = 30–50 mL/min)
or severe (CLcr <30 mL/min) renal impairment groups, the AUC of vardenafil
was 20–30% higher compared to that observed in a control group with normal
renal function (CLcr >80 mL/min). Vardenafil pharmacokinetics have not been
evaluated in patients requiring renal dialysis [see DOSAGE AND
ADMINISTRATION, WARNINGS AND PRECAUTIONS, and Use In Specific
Populations].
Clinical Studies
The efficacy and safety of STAXYN were evaluated in two
identical multi-national, randomized, double-blind, placebo-controlled trials (studies
1 and 2). STAXYN was dosed without regard to meals on an as-needed basis in men
with erectile dysfunction (ED), many of whom had multiple other medical
conditions. In both pivotal studies, randomization was stratified so that
approximately 50% of patients were ≥ 65 years old. Primary efficacy
assessment was by means of the Erectile Function (EF) Domain score of the
validated International Index of Erectile Function (IIEF) Questionnaire and two
questions from the Sexual Encounter Profile (SEP) dealing with the ability to
achieve vaginal penetration (SEP2), and the ability to maintain an erection
long enough for successful intercourse (SEP3). The primary endpoints were
assessed at 3 months.
Study 1 evaluated 355 mainly European (Belgium, France,
Germany, Spain, South Africa, and Netherlands) patients (mean age 61.9; 67%
White, 4% Black, 3% Asian, 26% Unknown). The mean baseline EF domain scores
were 13 for both placebo and STAXYN groups. Study 2 evaluated 331 mainly North
American (USA, Canada, Mexico, and Australia) patients (mean age 61.7; 69%
White, 5% Black, 4% Asian, 22% Hispanic). The mean baseline EF domain scores
were 12 for STAXYN and 13 for placebo.
In both studies STAXYN demonstrated clinically meaningful
and statistically significant improvements over placebo in all 3 primary
efficacy variables (see Table 7).
Table 7: Change from Baseline for the Primary Efficacy
Variables in Studies 1 and 2
EF Domain Score |
Study 1 |
Study 2 |
Placebo
(N=172) |
STAXYN
(N=181) |
p-value |
Placebo
(N=160) |
STAXYN
(N=167) |
p-value |
Endpoint |
14 |
21 |
|
14 |
21 |
|
Change from baseline |
1.6 |
8.7 |
<.0001 |
1.5 |
8.5 |
<.0001 |
Insertion of Penis (SEP2) |
(N=169) |
(N=179) |
|
(N=161) |
(N=168) |
|
Endpoint |
45% |
74% |
|
43% |
69% |
|
Change from baseline |
6.9% |
35.9% |
<.0001 |
4.8% |
30.8% |
<.0001 |
Maintenance of Erection (SEP3) |
(N=164) |
(N=178) |
|
(N=160) |
(N=168) |
|
Endpoint |
26% |
65% |
|
27% |
60% |
|
Change from baseline |
11.6% |
51.6% |
<.0001 |
12.4% |
45.9% |
<.0001 |
Other Vardenafil Clinical
Trials Using Film-Coated Tablets
Patients With ED And Diabetes
Mellitus
Vardenafil demonstrated
clinically meaningful and statistically significant improvement in erectile
function in a prospective, fixed-dose [10 and 20 mg vardenafil film-coated
tablets], double-blind, placebo-controlled trial of patients with diabetes mellitus
(n=439; mean age 57 years, range 33–81; 80% White, 9% Black, 8% Hispanic, and
3% Other).
Significant improvements in the
EF Domain were shown in this study (EF Domain scores of 17 on 10 mg vardenafil
and 19 on 20 mg vardenafil compared to 13 on placebo; p <0.0001).
Vardenafil significantly
improved the overall per-patient rate of achieving an erection sufficient for
penetration (SEP2) (61% on 10 mg and 64% on 20 mg vardenafil compared to 36% on
placebo; p <0.0001).
Vardenafil demonstrated a
clinically meaningful and statistically significant increase in the overall
per-patient rate of maintenance of erection to successful intercourse (SEP3)
(49% on 10 mg, 54% on 20 mg vardenafil compared to 23% on placebo; p
<0.0001).
Patients With ED After Radical Prostatectomy
Vardenafil demonstrated clinically meaningful and
statistically significant improvement in erectile function in a prospective,
fixed-dose 10 and 20 mg vardenafil film-coated tablets, double-blind,
placebo-controlled trial in postprostatectomy patients (n=427, mean age 60,
range 44–77 years; 93% White, 5% Black, 2% Other).
Significant improvements in the EF Domain were shown in
this study (EF Domain scores of 15 on 10 mg vardenafil and 15 on 20 mg
vardenafil compared to 9 on placebo; p <0.0001).
Vardenafil significantly improved the overall per-patient
rate of achieving an erection sufficient for penetration (SEP2) (47% on 10 mg
and 48% on 20 mg vardenafil compared to 22% on placebo; p <0.0001).
Vardenafil demonstrated a clinically meaningful and
statistically significant increase in the overall per-patient rate of
maintenance of erection to successful intercourse (SEP3) (37% on 10 mg, 34% on
20 mg vardenafil compared to 10% on placebo; p <0.0001).