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Pilot Study: Understanding Pain Relief with Naproxen and Pregabalin

This pilot study, called HEMP, is looking for up to 25 healthy adults to help understand how different pain medicines work. You would receive single doses of naproxen (an anti-inflammatory), pregabalin (which affects the brain and spinal cord), and a placebo (an inactive substance that looks like the real medicine). Researchers will then use short, controlled pain tests, like a cold pressor test or applying heat/capsaicin, to see how these medicines affect different types of pain. The main goal is to see if this testing method can show how naproxen and pregabalin relieve pain and distinguish between their different ways of working in the body. This study is currently recruiting participants.

Study design
This is a randomized, double-blind, 3-period crossover study involving up to 25 healthy adults.
What's involved
You would participate in a screening phase and a treatment phase with three periods, receiving one dose of medicine per period with at least 48 hours between doses. Assessments will occur at baseline and for 8 hours after each drug administration.
Compensation
Not stated in the trial record.
Follow-up
Pain intensity will be measured at approximately 2, 5, and 8 hours after dosing in each treatment period.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT07549490

Human Experimental Models of Pain (HEMP)

Not Yet Recruiting
NAAges 18+InterventionalBasic science
National Center for Complementary and Integrative Health (NCCIH)
~25 participants
Updated 2026-08-28 on ClinicalTrials.gov
What's tested:PlaceboNaproxenPregabalin

At a glance

Recruiting sites
0 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Change from baseline in pain intensity after cold pressor test
Measured over Baseline and approximately 2, 5, and 8 hours after dosing in each treatment period
+4 more outcomes measured

Conditions

Acute Pain

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Acute Pain

Where it's being run

1 sites across 1 states
Maryland1

Study leadership

  • Miroslav Backonja, M.D. · PRINCIPAL_INVESTIGATOR · National Center for Complementary and Integrative Health (NCCIH)

Who to contact

Miroslav Backonja, M.D.
[email protected]
(301) 402-5679
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Voluntarily consent to participate and provide written informed consent prior to the start of any study-specific procedures.
Read and speak English fluently.
State willingness to comply with all study procedures and availability for the duration of the study.
Are not pregnant or breastfeeding.
Are 18 or older years of age at screening.
Have a skin type score between 2 and 5 (inclusive) on the Fitzpatrick Scale.
Must correctly identify at least nine out of 12 temperatures (32 degrees Celsius, 38 degrees Celsius, 44 degrees Celsius, and 50 degrees Celsius, each presented three times) during the sensory discrimination test at screening.
Provide a verbal pain rating between 4 and 9 (inclusive) during the intradermal capsaicin challenge at screening. The study team will verify tolerability, and participants will continue only after it has been confirmed.
During the cold pressor test at screening, provide a verbal pain rating between 4 and 9 (inclusive) and keep one hand completely immersed in ice-cold water (1-4 degrees Celsius) between 1 and 4 minutes (inclusive). The study team will verify tolerability, and participants will continue only after it has been confirmed.
Are able to learn and perform all quantitative sensory testing QST procedures (see the separate QST manual).
Have the ability to take oral medication and be willing to adhere to the study intervention regimen.

Exclusion

Have a history or presence of clinically significant cardiovascular, pulmonary, hepatic, renal, hematologic, gastrointestinal, endocrine, immunologic, dermatologic, neurologic, oncologic, or psychiatric disease or any other condition that, in the opinion of the Investigator, would jeopardize the safety of the participant or the validity of the study results.
Have alcohol or drug dependence (excluding nicotine and caffeine) within the past 2 years, as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision (DSM IV-TR) and/or participants who have ever been in a substance or alcohol rehabilitation program to treat their substance dependence are currently seeking such treatment.
Have a clinically significant abnormal finding on the physical exam, medical history, or clinical laboratory results at screening.
Have a history of psychotic reactions, a non-psychotic emotional disorder, or another mental illness that, in the opinion of the investigator, may affect the ability of the participant to participate in the study.
Have recent history of suicidal ideation or suicidal behavior within the past 6 months, as assessed by the Columbia- Suicide Severity Rating Scale (C-SSRS) at screening (baseline version) or at check-in ( Since Last Visit version).
Have a history of allergy or hypersensitivity to pregabalin or other gabapentinoids, naproxen or other NSAIDs, or another ingredient in the study drugs, or anything else that, in the opinion of the Investigator, could put the participant at risk.
Have participated in another clinical trial (randomized participants only) within 30 days prior to the first dose of study medication.
Use any prescription medication, except hormonal contraceptive or hormonal replacement therapy, from 14 days prior to the first dose of study medication until study participation has ended without evaluation and approval by the Investigator.
Donate blood or plasma within 30 days prior to the first dose of study medication until the end of study participation. It is recommended that participants not donate blood or plasma until at least 30 days after their study participation has ended.
Female participants who are currently pregnant or breastfeeding, or who are planning to become pregnant during the study or within 30 days after the last study drug administration.
Show a positive urine alcohol test at screening.
Have smoked or used tobacco- or nicotine-containing products within 30 days prior to the first dose of study treatment until the end of the study.
Have an allergy to capsaicin or another capsaicinoid.
Have a tattoo, excessive scarring or discoloration, keloid formation, or, at the Investigator s discretion, otherwise unhealthy skin (e.g., eczema, psoriasis, burn, and cut) at a QST site.
Have a significant history of nerve injury or damage at a QST site, at the Investigator s discretion.
Participants who report any stimulus as intolerable at any point during the screening procedures will be excluded from participation.

What this trial measures

  • Change from baseline in pain intensity after cold pressor testBaseline and approximately 2, 5, and 8 hours after dosing in each treatment period

    Change from baseline in participant-rated pain intensity VAS score measured immediately after hand removal from cold water during the cold pressor test (CPT). Higher scores indicate greater pain intensity.

  • Change from baseline in pain intensity for allodynia (soft brush) after first heat/capsaicin pain model applicationBaseline and approximately 2, 5, and 8 hours after dosing in each treatment period

    Change from baseline in participant-rated pain intensity VAS score for soft-brush allodynia at the heat/capsaicin pain model (HCM) site after the first HCM application. Higher scores indicate greater pain intensity.

  • Change from baseline in pain intensity for hyperalgesia (pin-prick) after first heat/capsaicin pain model applicationBaseline and approximately 2, 5, and 8 hours after dosing in each treatment period

    Change from baseline in participant-rated pain intensity VAS score for pin-prick hyperalgesia at the HCM site after the first HCM application. Higher scores indicate greater pain intensity.

  • Change from baseline in pain intensity for mechanical hyperalgesia (pin-prick) at the UVB siteBaseline and approximately 2, 5, and 8 hours after dosing in each treatment period

    Change from baseline in participant-rated pain intensity VAS score for pin-prick hyperalgesia at the UVB-treated skin site. Higher scores indicate greater pain intensity.

  • Change from baseline in pain intensity for thermal hyperalgesia (heat pain) at the UVB siteBaseline and approximately 2, 5, and 8 hours after dosing in each treatment period

    Change from baseline in participant-rated pain intensity VAS score for thermal-heat pain hyperalgesia at the UVB-treated skin site. Higher scores indicate greater pain intensity.