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Use of Sildenafil (Viagra) to Alter Fatigue, Functional Status and Impaired Cerebral Blood Flow in Patients With CFS

Phase 4 Study of the Use of Sildenafil (Viagra) to Alter Fatigue, Functional Status and Impaired Cerebral Blood Flow in Patients With Chronic Fatigue Syndrome.

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00598585
Enrollment
12
Registered
2008-01-22
Start date
2002-07-31
Completion date
2010-12-31
Last updated
2017-06-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Chronic Fatigue Syndrome

Brief summary

Use of Viagra to Alter Symptoms in Patients with Chronic Fatigue Syndrome (CFS)

Detailed description

Use of Sildenafil (Viagra) to Alter Fatigue, Functional Status and Impaired Cerebral Blood Flow in Patients with Chronic Fatigue Syndrome.

Interventions

25 mg tid of either Sildenafil(Viagra) for first week. 50 mg tid of either Sildenafil (Viagra) for second week. 100 mg tid of either Sildenafil (Viagra) 3rd,4th, 5th and 6th week of study participation.

DRUGPlacebo

Placebo pills 3X/day for 6 weeks

Sponsors

Pfizer
CollaboratorINDUSTRY
Charles Drew University of Medicine and Science
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to 49 Years
Healthy volunteers
Yes

Inclusion criteria

* Patients meeting the CDC definition of CFS. * All races, ethnicities, socio-economic status (SES), and gender * Age greater than 18 (because of concerns about radioactivity, we and the Cedars-Sinai and Harbor-UCLA IRBs have decided not to enroll subjects below the age of 18). * Age less than 50. Because of concern of sildenafil exacerbating coronary artery disease, we will only enroll patients younger than 50. * Able to provide informed consent. * Willingness to be off all medicines and supplements for 3 weeks prior to the study. * Patients with psychiatric disorders (see below) will be included, if they could be off their medications, and if their psychiatric diagnosis clearly occurred after their fatigue symptoms began. * Patients with concurrent fibromyalgia will be allowed to participate if the meet diagnostic criteria for CFS.

Exclusion criteria

* Disabilities that would prevent them from participating in the study. * Current use of prescription medicines (starting at 3 weeks prior to the study) and supplements (starting at 1 weeks prior to the study) except acetaminophen or aspirin. This includes herbal supplements and vitamins. * Existing medical illnesses, such as heart disease, hypertension, cancer, rheumatological diseases, endocrinopathies or hormone replacement therapy, seizure disorders, severe obesity (BMI \> 32 kg/m2), * Severe psychiatric disorders including bipolar disorder, schizophrenia, dementia and previous or current diagnosis of alcohol or substance abuse within the past year. Patients with depression of such severity as to warrant treatment with anti-depressants will be excluded. * Current abuse of illicit drugs or heavy ethanol use. * Pregnant women will be excluded because of radioactivity exposure from the SPECT scans. * Abnormal EKG * Abnormal CBC, blood chemistries, thyroid function tests, and HIV, ANA, RF and ESR tests.

Design outcomes

Primary

MeasureTime frameDescription
Change in Fatigue Impact Scale at 6 Weeks6 weekschange in fatigue impact scale there are 42 questions. Each question can be answered from 0 (no problem) to 4 (extreme problem), so a higher score indicates more severe fatigue impact. minimum score=0, maximum score =148 values are calculated at baseline and 6 months and the score at 6 months compared to baseline months is calculated

Countries

United States

Participant flow

Participants by arm

ArmCount
Sildenafil
Sildenafil(Viagra): 25 mg tid of Sildenafil(Viagra) for first week. 50 mg tid of Sildenafil (Viagra) for second week. 100 mg tid of Sildenafil (Viagra) for 3rd,4th, 5th and 6th week of study participation.
6
Placebo
Placebo: Placebo tid for 6 weeks
6
Total12

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyLost to Follow-up10

Baseline characteristics

CharacteristicPlaceboTotalSildenafil
Age, Continuous38 years
STANDARD_DEVIATION 9
38 years
STANDARD_DEVIATION 5
39 years
STANDARD_DEVIATION 6
Ethnicity (NIH/OMB)
Hispanic or Latino
2 Participants3 Participants1 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
4 Participants9 Participants5 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Black or African American
0 Participants0 Participants0 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
6 Participants12 Participants6 Participants
Sex: Female, Male
Female
4 Participants9 Participants5 Participants
Sex: Female, Male
Male
2 Participants3 Participants1 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
1 / 50 / 6
serious
Total, serious adverse events
0 / 50 / 6

Outcome results

Primary

Change in Fatigue Impact Scale at 6 Weeks

change in fatigue impact scale there are 42 questions. Each question can be answered from 0 (no problem) to 4 (extreme problem), so a higher score indicates more severe fatigue impact. minimum score=0, maximum score =148 values are calculated at baseline and 6 months and the score at 6 months compared to baseline months is calculated

Time frame: 6 weeks

ArmMeasureValue (MEAN)Dispersion
SildenafilChange in Fatigue Impact Scale at 6 Weeks-32.6 units on a scaleStandard Deviation 31.5
PlaceboChange in Fatigue Impact Scale at 6 Weeks-1.5 units on a scaleStandard Deviation 12.2
p-value: <0.05t-test, 2 sided

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026