Trial Outcomes & Findings for The Effect of Sildenafil and Tadalafil on Skeletal Muscle and Perceptual Fatigue (NCT NCT01661595)

NCT ID: NCT01661595

Last Updated: 2018-07-17

Results Overview

Isokinetic Fatigue Measure (knee extension) is measured on a Biodex System Pro 4 within a 75 degree range of motion. Subjects performed concentric contractions at a fixed speed of 120 degree/sec. 50 contractions were performed at 100% force, one contraction every second. Isokinetic fatigue will be measured at week 4 and week 8. Depending on grouping, the week 4 and week 8 measures may be placebo or active drug. Data will be reported as after 4 weeks of placebo or after 4 weeks of active drug. Data is presented as mean maximum force over all 50 kicks.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

30 participants

Primary outcome timeframe

after 4 weeks of placebo

Results posted on

2018-07-17

Participant Flow

Participants were recruited from the community via flyers and local postings.

30 subjects enrolled in this study. 6 subjects failed the screening and were withdrawn. 6 subjects chose to withdraw participation before the study began. 18 subjects began the study. 2 subjects were withdrawn during the study. 16 subjects completed the study.

Participant milestones

Participant milestones
Measure
Sildenafil, Then Placebo
Sildenafil daily (50mg/day) for weeks 0-4. Then Placebo daily for weeks 5-8.
Tadalfil, Then Placebo
Tadalafil (10mg/day) for week 0-4. Then Placebo daily for week 5-8.
Placebo, Then Sildenafil
Placebo daily for weeks 0-4. Then Sildenafil daily (50mg/day) for weeks 5-8.
Placebo, Then Tadalafil
Placebo for week 0-4, then Tadalafil (10mg/day) for week 5-8.
Phase 1: Week 0-4
STARTED
5
4
5
4
Phase 1: Week 0-4
COMPLETED
4
4
5
4
Phase 1: Week 0-4
NOT COMPLETED
1
0
0
0
Phase 2: Week 5-8.
STARTED
4
4
5
4
Phase 2: Week 5-8.
COMPLETED
4
4
4
4
Phase 2: Week 5-8.
NOT COMPLETED
0
0
1
0

Reasons for withdrawal

Reasons for withdrawal
Measure
Sildenafil, Then Placebo
Sildenafil daily (50mg/day) for weeks 0-4. Then Placebo daily for weeks 5-8.
Tadalfil, Then Placebo
Tadalafil (10mg/day) for week 0-4. Then Placebo daily for week 5-8.
Placebo, Then Sildenafil
Placebo daily for weeks 0-4. Then Sildenafil daily (50mg/day) for weeks 5-8.
Placebo, Then Tadalafil
Placebo for week 0-4, then Tadalafil (10mg/day) for week 5-8.
Phase 1: Week 0-4
Adverse Event
1
0
0
0
Phase 2: Week 5-8.
Protocol Violation
0
0
1
0

Baseline Characteristics

The Effect of Sildenafil and Tadalafil on Skeletal Muscle and Perceptual Fatigue

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Sildenafil, Then Placebo
n=5 Participants
Sildenafil (50mg/day) daily for weeks 0-4, then Placebo daily weeks 5-8.
Tadalfil, Then Placebo
n=4 Participants
Tadalafil (10mg/day) daily for weeks 0-4, then Placebo daily for weeks 5-8.
Placebo, Then Sildenafil
n=5 Participants
Placebo daily for weeks 0-4, then Sildenafil (50mg/day) daily for weeks 5-8.
Placebo, Then Tadalafil
n=4 Participants
Placebo daily for weeks 0-4, then Tadalafil (10mg/day) daily for weeks 5-8.
Total
n=18 Participants
Total of all reporting groups
Age, Continuous
53.6 years
STANDARD_DEVIATION 4.16 • n=5 Participants
56 years
STANDARD_DEVIATION 1.41 • n=7 Participants
52.4 years
STANDARD_DEVIATION 1.51 • n=5 Participants
57.25 years
STANDARD_DEVIATION 2.99 • n=4 Participants
54.6 years
STANDARD_DEVIATION 3.22 • n=21 Participants
Sex: Female, Male
Female
4 Participants
n=5 Participants
4 Participants
n=7 Participants
3 Participants
n=5 Participants
2 Participants
n=4 Participants
13 Participants
n=21 Participants
Sex: Female, Male
Male
1 Participants
n=5 Participants
0 Participants
n=7 Participants
2 Participants
n=5 Participants
2 Participants
n=4 Participants
5 Participants
n=21 Participants
Region of Enrollment
United States
5 Participants
n=5 Participants
4 Participants
n=7 Participants
5 Participants
n=5 Participants
4 Participants
n=4 Participants
18 Participants
n=21 Participants

PRIMARY outcome

Timeframe: after 4 weeks of placebo

Isokinetic Fatigue Measure (knee extension) is measured on a Biodex System Pro 4 within a 75 degree range of motion. Subjects performed concentric contractions at a fixed speed of 120 degree/sec. 50 contractions were performed at 100% force, one contraction every second. Isokinetic fatigue will be measured at week 4 and week 8. Depending on grouping, the week 4 and week 8 measures may be placebo or active drug. Data will be reported as after 4 weeks of placebo or after 4 weeks of active drug. Data is presented as mean maximum force over all 50 kicks.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Skeletal Muscle Fatigue as Measured by Biodex 4 Pro After 4 Weeks of Placebo
59.69 Newton-Meters
Standard Deviation 33.71
42.07 Newton-Meters
Standard Deviation 5.19
67.17 Newton-Meters
Standard Deviation 26.87
63.24 Newton-Meters
Standard Deviation 8.34

PRIMARY outcome

Timeframe: after 4 weeks of active drug

Isokinetic Fatigue Measure (knee extension) is measured on a Biodex System Pro 4 within a 75 degree range of motion. Subjects performed concentric contractions at a fixed speed of 120 degree/sec. 50 contractions were performed at 100% force, one contraction every second. Isokinetic fatigue will be measured at week 4 and week 8. Depending on grouping, the week 4 and week 8 measures may be placebo or active drug. Data will be reported as after 4 weeks of placebo or after 4 weeks of active drug. Data is presented as mean maximum force over all 50 kicks.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Skeletal Muscle Fatigue as Measured by Biodex 4 Pro After 4 Weeks of Active Drug
60.90 Newton-Meters
Standard Deviation 35.60
42.48 Newton-Meters
Standard Deviation 6.30
62.68 Newton-Meters
Standard Deviation 24.88
63.25 Newton-Meters
Standard Deviation 15.12

PRIMARY outcome

Timeframe: after 4 weeks of placebo

The fatigue rating scale is a scale from 0 to 10 with 0 being no fatigue at all and 10 being the worst fatigue the subject can imagine. The subject is asked to rate their level of fatigue in their leg. This test was performed before and immedicately after the Biodex leg fatigue test after 4 weeks of placebo. Data is presented as change in scale from pre fatigue test to post fatigue test, with a higher score indicating a greater level of fatigue.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Exercised Induced Fatigability as Measured by Fatigue Rating Scale After 4 Weeks of Placebo
4.33 units on a scale
Standard Deviation 1.53
2.5 units on a scale
Standard Deviation 0.58
7.0 units on a scale
Standard Deviation 1.83
4.75 units on a scale
Standard Deviation 0.96

PRIMARY outcome

Timeframe: after 4 weeks of active drug

The fatigue rating scale is a scale from 0 to 10 with 0 being no fatigue at all and 10 being the worst fatigue the subject can imagine. The subject is asked to rate their level of fatigue in their leg. This test was performed before and immedicately after the Biodex leg fatigue test. Data is presented as change in scale from pre fatigue test to post fatigue test, with a higher score indicating a greater level of fatigue.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Exercised Induced Fatigability as Measured by Fatigue Rating Scale After 4 Weeks of Active Drug
4.5 units on a scale
Standard Deviation 2.38
3.5 units on a scale
Standard Deviation 1.73
5.25 units on a scale
Standard Deviation 4.27
6.0 units on a scale
Standard Deviation 1.83

SECONDARY outcome

Timeframe: after 4 weeks of placebo

Peak isometric strength is measured on a Biodex System 4 Pro. This test is isolated to the quadricep muscle of one leg. Isometric test is performed at 90 degrees with 5 seconds of force production for each contraction and 15 seconds of rest. 1 set of 3 contractions at 100% force performed. Isometric strength was measured at week 4 and week 8. Depending on grouping, the week 4 and week 8 measures may be placebo or active drug. Data will be reported as after 4 weeks of placebo or after 4 weeks of active drug.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Maximum Peak Isometric Leg Strength as Measured by Biodex Pro4 After 4 Weeks of Placebo
145.86 Newton-Meters
Standard Deviation 97.73
104.17 Newton-Meters
Standard Deviation 23.66
149.14 Newton-Meters
Standard Deviation 62.67
148.34 Newton-Meters
Standard Deviation 47.26

SECONDARY outcome

Timeframe: after 4 weeks of active drug

Peak isometric strength is measured on a Biodex System 4 Pro. This test is isolated to the quadricep muscle of one leg. Isometric test is performed at 90 degrees with 5 seconds of force production for each contraction and 15 seconds of rest. 1 set of 3 contractions at 100% force performed. Isometric strength was measured at week 4 and week 8. Depending on grouping, the week 4 and week 8 measures may be placebo or active drug. Data will be reported as after 4 weeks of placebo or after 4 weeks of active drug.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Maximum Peak Isometric Leg Strength as Measured by Biodex Pro4 After 4 Weeks of Active Drug.
140.09 Newton-Meters
Standard Deviation 82.29
110.39 Newton-Meters
Standard Deviation 21.26
133.81 Newton-Meters
Standard Deviation 58.04
139.96 Newton-Meters
Standard Deviation 50.47

SECONDARY outcome

Timeframe: after 4 weeks of placebo

Isokinetic strength (knee extension) is measured on a Biodex System Pro 4 within a 75 degree range of motion. Subjects performed concentric contractions at a fixed speed of 120 degree/sec. 1 set of 3 contractions were performed at 100% force. Isokinetic strength will be measured at week 4 and week 8. Depending on grouping, the week 4 and week 8 measures may be placebo or active drug. Data will be reported as after 4 weeks of placebo or after 4 weeks of active drug.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Maximum Peak Isokinetic Leg Strength as Measured by Biodex Pro4 After 4 Weeks of Placebo.
105.15 Newton-Meters
Standard Deviation 49.46
78.59 Newton-Meters
Standard Deviation 10.25
117.71 Newton-Meters
Standard Deviation 39.86
111.67 Newton-Meters
Standard Deviation 23.43

SECONDARY outcome

Timeframe: after 4 weeks of active drug

Isokinetic strength (knee extension) is measured on a Biodex System Pro 4 within a 75 degree range of motion. Subjects performed concentric contractions at a fixed speed of 120 degree/sec. 1 set of 3 contractions were performed at 100% force. Isokinetic strength will be measured at week 4 and week 8. Depending on grouping, the week 4 and week 8 measures may be placebo or active drug. Data will be reported as after 4 weeks of placebo or after 4 weeks of active drug.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Maximum Peak Isokinetic Leg Strength as Measured by Biodex Pro4 After 4 Weeks of Active Drug
106.79 Newton-Meters
Standard Deviation 49.69
79.33 Newton-Meters
Standard Deviation 11.69
116.48 Newton-Meters
Standard Deviation 37.83
114.75 Newton-Meters
Standard Deviation 36.49

SECONDARY outcome

Timeframe: week 0

Lean Body Mass is calculated from a whole body scan measured on a dual energy x-ray absorptiometry.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=5 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=5 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Lean Body Mass as Measured by Dual Energy X-ray Absorptiometry at Week 0.
44.60 kilograms
Standard Deviation 11.62
41.43 kilograms
Standard Deviation 4.72
49.93 kilograms
Standard Deviation 10.63
54.45 kilograms
Standard Deviation 14.28

SECONDARY outcome

Timeframe: week 4

Lean Body Mass is calculated from a whole body scan measured on a dual energy x-ray absorptiometry.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=5 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Lean Body Mass as Measured by Dual Energy X-ray Absorptiometry at Week 4.
46.29 kilograms
Standard Deviation 14.40
41.02 kilograms
Standard Deviation 4.05
50.61 kilograms
Standard Deviation 10.67
54.85 kilograms
Standard Deviation 14.71

SECONDARY outcome

Timeframe: week 8

Lean Body Mass is calculated from a whole body scan measured on a dual energy x-ray absorptiometry.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Lean Body Mass as Measured by Dual Energy X-ray Absorptiometry at Week 8.
46.22 kilograms
Standard Deviation 14.68
40.76 kilograms
Standard Deviation 4.38
52.09 kilograms
Standard Deviation 10.03
55.10 kilograms
Standard Deviation 14.42

SECONDARY outcome

Timeframe: week 0

Fat Mass is calculated from a whole body scan measured on a dual energy x-ray absorptiometry.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=5 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=5 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Fat Mass as Measured by Dual Energy X-ray Absorptiometry at Week 0.
32.35 kilograms
Standard Deviation 11.40
37.21 kilograms
Standard Deviation 6.81
32.72 kilograms
Standard Deviation 5.92
32.10 kilograms
Standard Deviation 6.90

SECONDARY outcome

Timeframe: week 4

Fat Mass is calculated from a whole body scan measured on a dual energy x-ray absorptiometry.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=5 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Fat Mass as Measured by Dual Energy X-ray Absorptiometry at Week 4.
33.16 kilograms
Standard Deviation 12.42
37.12 kilograms
Standard Deviation 6.35
32.30 kilograms
Standard Deviation 5.55
32.47 kilograms
Standard Deviation 7.08

SECONDARY outcome

Timeframe: week 8

Fat Mass is calculated from a whole body scan measured on a dual energy x-ray absorptiometry.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Fat Mass as Measured by Dual Energy X-ray Absorptiometry at Week 8.
33.60 kilograms
Standard Deviation 12.51
37.02 kilograms
Standard Deviation 6.21
32.40 kilograms
Standard Deviation 5.83
32.79 kilograms
Standard Deviation 7.12

SECONDARY outcome

Timeframe: after 4 weeks of placebo

Population: 1 subject did not complete the walking test

Walking performance will be assessed during 2 minutes of walking in long corridor hallways. Subjects will be asked to walk at 100% effort (as quickly as they can safely walk without running) for 2 minutes. Distance traveled for the 2 minutes will be recorded. The walking test will be completed at week 4 and week 8. Depending on grouping, the week 4 and week 8 measures may be placebo or active drug. Data will be reported as after 4 weeks of placebo or after 4 weeks of active drug.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=3 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Walking Distance at 100% Effort as Measured by Walking Test After 4 Weeks of Placebo
203.82 meters
Standard Deviation 30.51
189.79 meters
Standard Deviation 38.12
198.41 meters
Standard Deviation 14.04
202.80 meters
Standard Deviation 37.84

SECONDARY outcome

Timeframe: after 4 weeks of active drug

Population: 1 subject did not complete the walking test.

Walking performance will be assessed during 2 minutes of walking in long corridor hallways. Subjects will be asked to walk at 100% effort (as quickly as they can safely walk without running) for 2 minutes. Distance traveled for the 2 minutes will be recorded. The walking test will be completed at week 4 and week 8. Depending on grouping, the week 4 and week 8 measures may be placebo or active drug. Data will be reported as after 4 weeks of placebo or after 4 weeks of active drug.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=3 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Walking Distance at 100% Effort as Measured by Walking Test After 4 Weeks of Active Drug
197.01 meter
Standard Deviation 32.72
178.56 meter
Standard Deviation 17.84
200.19 meter
Standard Deviation 13.99
203.46 meter
Standard Deviation 31.11

SECONDARY outcome

Timeframe: Week 0

Fatigue symptoms will be measured using the 30-item Multidimensional Fatigue Symptom Inventory - Short Form, a validated measure that yields one overall score of total fatigue calculated using five sub scales (general, physical, emotional, mental, vigor). With the exception of the vigor sub scale, higher scores indicate greater fatigue. Total fatigue score is calculated by summing the sub categories (general, physical, emotional and mental) and subtracting vigor. Total scores range from -24 to 96, with a higher score indicating more fatigue.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Perceptual Fatigue as Measured by Multidimensional Fatigue Symptom Inventory - Short Form Total Score at Week 0
9.66 scores on a scale
Standard Deviation 19.55
-7.5 scores on a scale
Standard Deviation 5.45
-8 scores on a scale
Standard Deviation 3.61
-3.75 scores on a scale
Standard Deviation 9.54

SECONDARY outcome

Timeframe: week 4

Population: 1 subject did not complete the week 4 MFSI questionnaire

Fatigue symptoms will be measured using the 30-item Multidimensional Fatigue Symptom Inventory - Short Form, a validated measure that yields one overall score of total fatigue calculated using five sub scales (general, physical, emotional, mental, vigor). With the exception of the vigor sub scale, higher scores indicate greater fatigue. Total fatigue score is calculated by summing the sub categories (general, physical, emotional and mental) and subtracting vigor. Total scores range from -24 to 96, with a higher score indicating more fatigue.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=3 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Perceptual Fatigue as Measured by Multidimensional Fatigue Symptom Inventory - Short Form Total Score at Week 4
6.33 scores on a scale
Standard Deviation 26.08
-3.33 scores on a scale
Standard Deviation 10.97
-6.33 scores on a scale
Standard Deviation 2.31
-3.5 scores on a scale
Standard Deviation 12.66

SECONDARY outcome

Timeframe: week 8

Fatigue symptoms will be measured using the 30-item Multidimensional Fatigue Symptom Inventory - Short Form, a validated measure that yields one overall score of total fatigue calculated using five sub scales (general, physical, emotional, mental, vigor). With the exception of the vigor sub scale, higher scores indicate greater fatigue. Total fatigue score is calculated by summing the sub categories (general, physical, emotional and mental) and subtracting vigor. Total scores range from -24 to 96, with a higher score indicating more fatigue.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Perceptual Fatigue as Measured by Multidimensional Fatigue Symptom Inventory - Short Form Total Score at Week 8
9.67 scores on a scale
Standard Deviation 19.09
3.25 scores on a scale
Standard Deviation 27.54
-9.67 scores on a scale
Standard Deviation 6.81
-9.25 scores on a scale
Standard Deviation 1.26

OTHER_PRE_SPECIFIED outcome

Timeframe: week 0

Hemoglobin was measured by University of Texas Medical Branch Clinical Laboratory. Normal ranges are 11.6 - 15.0 g/dL.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Hemoglobin Level at Week 0
13.42 g/dL
Standard Deviation 0.97
12.78 g/dL
Standard Deviation 0.71
12.4 g/dL
Standard Deviation 0.53
13.05 g/dL
Standard Deviation 0.90

OTHER_PRE_SPECIFIED outcome

Timeframe: week 4

Hemoglobin was measured by University of Texas Medical Branch Clinical Laboratory. Normal ranges are 11.6 - 15.0 g/dL.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Hemoglobin Level Measured at Week 4
13.05 g/dL
Standard Deviation 0.49
12.03 g/dL
Standard Deviation 0.43
12.6 g/dL
Standard Deviation 0.37
13.2 g/dL
Standard Deviation 0.47

OTHER_PRE_SPECIFIED outcome

Timeframe: week 8

Hemoglobin was measured by University of Texas Medical Branch Clinical Laboratory. Normal ranges are 11.6 - 15.0 g/dL.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Hemoglobin Level Measured at Week 8
13.55 g/dL
Standard Deviation 0.35
11.97 g/dL
Standard Deviation 0.76
12.5 g/dL
Standard Deviation 0.08
12.95 g/dL
Standard Deviation 1.17

OTHER_PRE_SPECIFIED outcome

Timeframe: week 0

Hematocrit was measured by University of Texas Medical Branch Clinical Laboratory. Normal ranges are 35.7 - 45.2%.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Hematocrit Level Measured at Week 0
39.53 percent of red blood cells
Standard Deviation 2.16
38.55 percent of red blood cells
Standard Deviation 1.42
37.25 percent of red blood cells
Standard Deviation 2.07
31.88 percent of red blood cells
Standard Deviation 13.09

OTHER_PRE_SPECIFIED outcome

Timeframe: 4 weeks

Hematocrit was measured by University of Texas Medical Branch Clinical Laboratory. Normal ranges are 35.7 - 45.2%.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Hematocrit Level Was Measured at 4 Weeks
39.08 percent of red blood cells
Standard Deviation 0.84
37.38 percent of red blood cells
Standard Deviation 0.82
38.13 percent of red blood cells
Standard Deviation 0.77
39.1 percent of red blood cells
Standard Deviation 1.81

OTHER_PRE_SPECIFIED outcome

Timeframe: week 8

Hematocrit was measured by University of Texas Medical Branch Clinical Laboratory. Normal ranges are 35.7 - 45.2%.

Outcome measures

Outcome measures
Measure
Sildenafil, Then Placebo
n=4 Participants
50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 0-4. Placebo for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Tadalafil, Then Placebo
n=4 Participants
10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 0-4. Placebo for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Sildenafil
n=4 Participants
Placebo for weeks 0-4. 50 mg/day Sildenafil: (Other Name: Viagra, Revatio) for weeks 5-8. Sildenafil: 50 mg/day for 4 weeks Placebo: Placebo 1 capsule per day for four weeks.
Placebo, Then Tadalafil
n=4 Participants
Placebo for weeks 0-4. 10 mg/day Tadalafil: (Other Name: Cialis, Adcirca) for weeks 5-8. tadalafil: 10 mg/day for 4 weeks. Placebo: Placebo 1 capsule per day for four weeks.
Hematocrit Level Measured at Week 8
40.38 percent of red blood cells
Standard Deviation 0.44
36.6 percent of red blood cells
Standard Deviation 1.94
38.1 percent of red blood cells
Standard Deviation 1.19
38.4 percent of red blood cells
Standard Deviation 3.24

Adverse Events

Sildenafil

Serious events: 0 serious events
Other events: 2 other events
Deaths: 0 deaths

Tadalfil

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Placebo

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Sildenafil
n=10 participants at risk
Sildenafil (50mg/day) daily for 4 weeks.
Tadalfil
n=8 participants at risk
Tadalafil (10mg/day) daily for 4 weeks.
Placebo
n=18 participants at risk
Placebo daily for week 4 weeks.
Skin and subcutaneous tissue disorders
Redness at site of muscle biopsy
10.0%
1/10 • Number of events 1
0.00%
0/8
0.00%
0/18
General disorders
Syncope
10.0%
1/10 • Number of events 1
0.00%
0/8
0.00%
0/18

Additional Information

Melinda Sheffield-Moore

University of Texas Medical Branch

Phone: 409-772-8707

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place