Efficacy of Topical Lidocaine Gel vs. Oral Duloxetine for Painful Diabetic Peripheral Neuropathy

August 28, 2026 updated by: Wah Medical college , POF hospital

Comparison of the Efficacy of Topical Lidocaine Gel Versus Oral Duloxetine in the Treatment of Painful Diabetic Peripheral Neuropathy: A Prospective Randomized Controlled Trial

The goal of this clinical trial is to learn if topical lidocaine gel can effectively reduce pain intensity compared to oral duloxetine in adult patients (aged 30-70 years) with type 2 diabetes suffering from painful diabetic peripheral neuropathy. The main questions it aims to answer are:

Is there a significant difference in the reduction of pain intensity (measured by the Numeric Rating Scale) between topical lidocaine 2% gel and oral duloxetine after 8 weeks of treatment?

How does the safety and tolerability profile of topical lidocaine gel compare with oral duloxetine in this patient population?

Researchers will compare Group A (Topical Lidocaine 2% gel applied to the affected areas of both feet twice daily) to Group B (Oral Duloxetine 60 mg taken once daily) to see if topical lidocaine provides comparable pain relief to oral duloxetine with a reduction in systemic adverse drug reactions.

Participants will:

Complete a baseline clinical assessment, including nerve pain evaluation using the DN4 questionnaire and rating their pain severity on the Numeric Rating Scale (NRS).

Be randomly assigned to receive either topical lidocaine 2% gel applied twice daily to both feet or oral duloxetine capsules (30 mg once daily for 2 weeks, then escalated to 60 mg once daily) for 8 consecutive weeks.

Maintain their existing routine antidiabetic medications throughout the study.

Attend an interim safety check visit at Week 4 to report and document any side effects or adverse drug reactions.

Attend a final evaluation visit at Week 8 to record their post-treatment NRS pain score and complete safety reporting.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Painful diabetic peripheral neuropathy (PDPN) affects up to 26% of patients with diabetes, manifesting as burning, shooting, or electric-shock-like pain primarily in the lower extremities. While systemic medications such as duloxetine, a serotonin-norepinephrine reuptake inhibitor (SNRI), are standard first-line therapies, their clinical utility is frequently constrained by systemic side effects like nausea, dizziness, and somnolence. Topical lidocaine offers a site-specific alternative by blocking voltage-gated sodium channels in peripheral nociceptors, thereby minimizing systemic drug exposure. This prospective, open-label, parallel-group, randomized controlled trial is designed to evaluate and compare the efficacy and safety of topical lidocaine 2% gel versus oral duloxetine in patients with PDPN over an 8-week treatment period. A total of 80 adult patients (30-70 years of age) with type 2 diabetes and moderate-to-severe neuropathic pain (DN4 score greater than or equal to 4/10 and baseline NRS score greater than or equal 4/10) will be recruited from the Outpatient Department of General Medicine at POF Hospital, Wah Cantt. Participants will be randomized in a 1:1 ratio into two parallel treatment arms: Group A (Intervention): Topical lidocaine 2% gel applied as a thin layer to intact skin on the affected areas of both feet twice daily (maximum 6 g/day) for 8 weeks. Group B (Control): Oral duloxetine capsules initiated at 30 mg once daily for the first 2 weeks and escalated to 60 mg once daily for the remaining 6 weeks. The primary outcome measure is the change in pain intensity from baseline (Week 0) to Week 8, evaluated using the 11-point Numeric Rating Scale (NRS). Secondary outcome measures include the incidence, nature, and severity of adverse drug reactions reported at Week 4 and Week 8, as well as the proportion of participants requiring rescue paracetamol medication. Although blinding of participants and treating physicians is not feasible due to differing routes of administration, outcome assessments will be conducted by an independent assessor blinded to treatment allocation to minimize observer bias. Data will be analyzed on an intention-to-treat basis.

Study Type

Interventional

Enrollment (Estimated)

80

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adult patients aged 30 to 70 years
  • Confirmed type 2 diabetes mellitus (as per WHO 2019 criteria) for at least 1 year
  • HbA1c < or = 10% (or documented stable glycemic control over the preceding 3 months)
  • Diagnosis of painful diabetic peripheral neuropathy (PDPN) with a DN4 score > or = 4/10
  • Baseline Numeric Rating Scale (NRS) pain score >= 4/10 (moderate-to-severe pain)
  • Willing and able to provide written informed consent

Exclusion Criteria:

  • Known hypersensitivity or contraindication to lidocaine or duloxetine
  • Current use of other neuropathic pain medications (gabapentinoids, tricyclic antidepressants, opioids, or topical capsaicin) within 4 weeks of enrollment
  • Significant hepatic impairment (ALT or AST > 3 times the upper limit of normal)
  • Severe renal impairment (eGFR < 30 mL/min/1.73 m²)
  • Active skin lesions, open wounds, or dermatological conditions at the intended application site on the feet
  • Pregnant or lactating females
  • Other causes of peripheral neuropathy (e.g., alcohol-related, hypothyroidism, vitamin B12 deficiency, or Charcot-Marie-Tooth disease)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group A: Topical Lidocaine Gel
Participants receive topical lidocaine 2% gel applied as a thin layer to the affected areas of both feet twice daily (maximum 6 g/day) for 8 consecutive weeks.
Drug: Topical Lidocaine 2% Gel
Applied topically to intact skin of affected areas on both feet twice daily for 8 weeks (1-2 g per foot per application; not exceeding 6 g/day total).
Other Names:
  • Lidocaine gel
  • Topical Lidocaine
Active Comparator: Group B: Oral Duloxetine
Participants receive oral duloxetine delayed-release capsules initiated at 30 mg once daily for the first 2 weeks and then escalated to 60 mg once daily for the remaining 6 weeks (total treatment duration: 8 weeks).
Drug: Duloxetine (60 MG)
Administered orally as a delayed-release capsule: 30 mg once daily for 2 weeks, then increased to 60 mg once daily for 6 weeks (total 8 weeks).
Other Names:
  • Duloxetine hydrochloride

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Pain Intensity Score on the Numeric Rating Scale (NRS)
Time Frame: Baseline (Week 0) and Week 8
Measured on an 11-point Numeric Rating Scale (NRS) ranging from 0 (no pain) to 10 (worst imaginable pain). Participants rate their average pain over the preceding 24 hours. Change is calculated as Week 8 score minus Baseline (Week 0) score.
Baseline (Week 0) and Week 8

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence and Severity of Adverse Drug Reactions
Time Frame: Week 4 and Week 8
Number of participants reporting adverse drug reactions (ADRs), categorized by nature and severity (mild, moderate, or severe) as documented on the study proforma.
Week 4 and Week 8
Use of Rescue Paracetamol
Time Frame: Up to 8 weeks
Proportion of participants in each treatment group requiring paracetamol as rescue medication during the treatment period.
Up to 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Wah Medical college , POF hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

December 1, 2026

Primary Completion (Estimated)

March 1, 2027

Study Completion (Estimated)

April 1, 2027

Study Registration Dates

First Submitted

August 28, 2026

First Submitted That Met QC Criteria

August 28, 2026

First Posted (Actual)

September 2, 2026

Study Record Updates

Last Update Posted (Actual)

September 2, 2026

Last Update Submitted That Met QC Criteria

August 28, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • POFH/ 05-2026/ МЕD/11

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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