An Open Label, Dose Finding Trial of Viagra for the Treatment of Neuropathic Pain (in Diabetes Mellitus)

Diabetic Neuropathy Clinical Trial

Official title:

An Open Label, Dose Finding Trial of Viagra for the Treatment of Neuropathic Pain (in Diabetes Mellitus)

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00194909
• Other study ID #: 1103-032
• Status: Completed
• Phase: Phase 4
• First received: September 12, 2005
• Last updated: March 24, 2008
• Start date: August 2004
• Est. completion date: July 2006

Study information

• Verified date: March 2008
• Source: Weill Medical College of Cornell University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Food and Drug Administration
• Study type: Interventional

Clinical Trial Summary

The purpose of this study is to study if sildenafil (Viagra) is effective in improving neuropathic pain. This will be an open label study at 3 doses of sildenafil (25 mg, 50 mg and 100 mg). If this study suggests efficacy, the information will be used to plan a placebo controlled, double-blind study in the future.

Description:

Neuropathic pain is a common problem resulting from a diverse group of disorders including nerve injuries and neuropathies related to diabetes and other disorders. Pharmacologic agents are available such as gabapentin, which can successfully treat many patients. For many however there is inadequate treatment available, due to lack of efficacy and poor tolerability and the need for new pharmacologic agents is recognized.

We propose to study if sildenafil is effective in improving neuropathic pain, in patients with diabetes mellitus. Our primary outcome will be a reduction in the weekly average 11 point Likert pain scale (0 - no pain, 10 - worst possible pain) at 8 weeks. Secondary outcomes will include the Rand-36 quality of life scale, McGill visual analogue scale (VAS) and a sleep interference scale.

This will be an open label study at 3 doses of sildenafil (25 mg, 50 mg and 100 mg). Patients will begin at 25 mg at night for 1 week. If pain continues, the dose will be increased to 50 mg at night for 1 week. If pain continues the dose will be increased to 100 mg at night. Subjects will be on the medication for 8 weeks. If this study suggests efficacy, the information will be used to plan a placebo controlled, double-blind study in the future.

We propose to study if sildenafil is effective in improving neuropathic pain. Our primary outcome will be a reduction in the weekly average 11 point Likert pain scale (0 - no pain, 10 - worst possible pain) at 8 weeks. Secondary outcomes will include the Rand-36 quality of life scale, McGill visual analogue scale (VAS) and a sleep interference scale.

This will be an open label study at 3 doses of sildenafil (25 mg, 50 mg and 100 mg). Patients will begin at 25 mg at night for 1 week. If pain continues, the dose will be increased to 50 mg at night for 1 week. If pain continues the dose will be increased to 100 mg at night. Subjects will be on the medication for 8 weeks. If this study suggests efficacy, the information will be used to plan a placebo controlled, double-blind study in the future.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 8
• Est. completion date: July 2006
• Est. primary completion date: July 2006
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Patients with signs and symptoms of a diabetic peripheral neuropathy as diagnosed by a neurologist with neuropathic pain will be included. The pain will have been present for at least 6 months. Patients may be on other medications for neuropathic pain such as anti-epileptic medications or tricyclic anti-depressants, however must be on a stable dose for 4 weeks prior to and during the study. Eligible patients must have a score of at least 40 on the VAS.

Exclusion Criteria:

• Previous adverse reaction to viagra

• Blood pressure < 90/50 or > 170/100

• unstable angina

• retinitis pigmentosa,

• myocardial infarction stroke or life-threatening arrhythmia within the last 6 months

• hemoglobulin A1c > 11

• HIV infection

• history of priapism

• hepatic or renal failure

• pregnancy

• current or past use of nitrates

Study Design

Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Diabetes Mellitus
• Diabetic Neuropathies
• Diabetic Neuropathy
• Neuralgia

Intervention

Drug:
• sildenafil (Viagra)

Locations

Country	Name	City	State
United States	Peripheral Neuropathy Center - Weill Cornell Medical College	New York	New York

Sponsors (2)

Lead Sponsor	Collaborator
Weill Medical College of Cornell University	Pfizer

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Our primary outcome will be a reduction in the weekly average 11 point Likert pain scale (0 - no pain, 10 - worst possible pain) at 8 weeks.
Secondary	Secondary outcomes will include the Rand-36 quality of life scale, McGill visual analogue scale (VAS) and a sleep interference scale.