Clinical trials

Background: Opioid drugs are often prescribed for acute and chronic pain. But these drugs are addictive, and they lead to more than 14,000 overdose deaths in the United States each year. Researchers want to find new drugs that relieve pain but are not addictive. This study will test whether a single dose of an experimental drug called (2R,6R)-hydroxynorketamine (HNK) can help reduce short term pain in healthy adults. HNK is related to ketamine. Studies suggest HNK might be as effective as ketamine at reducing pain but that it might have fewer side effects. In this study we will test how HNK affects pain and emotion. The results of this study may help us understand whether HNK has pain relieving effects and how it works in the brain, which could inform future pain treatments. Objective: To test the study drug \[(2R,6R)-hydroxynorketamine (HNK)\] for treating acute pain in healthy people. Eligibility: Healthy people aged 18 to 60 years. Design; Up to 92 healthy volunteers between 18 and 60 years old without chronic pain or psychiatric conditions will participate in the study. The study will take place at the NIH Clinical Center in Bethesda, Maryland. Each participant s involvement will last up to two months. The overall study is expected to last about three years (36 months). The study has 2 parts. In part 1, participants will have up to 2 clinic visits. They will be screened and have blood draws to make sure they're eligible for the study. They will complete sensory testing and have MRI brain scans. Sensory testing involves feeling and rating painful and non-painful sensations. These may include hot or cold temperatures, pinches or squeezes, and being touched with brushes or pinpricks. Eligible participants will have an imaging scan that shows brain activity: During the scan, they will rate heat, hear pleasant or unpleasant sounds, and view unpleasant or pleasant pictures. After completing part 1, eligible participants will be invited to part 2, which includes overnight stays at NIH. In part 2, participants will be assigned to either a treatment group or a no-treatment group. The treatment group will have 2 overnight visits of 2 nights each. The visits will be 1 to 3 weeks apart. For one of the visits, treatment group participants will receive the study drug HNK. For the other visit, they will receive a placebo. A placebo looks just like the study drug but contains no medicine. HNK and placebo are given through a tube inserted into a vein in the arm. The sensory tests, blood draws, and MRI scans will be repeated at each visit. Participants will not be told whether they got the drug or placebo on each visit. The nontreatment group will have 1 overnight visit. They will not receive the drug or placebo. The sensory tests, blood draws, and MRI scans will be repeated. Participants cannot drink alcohol, use recreational drugs, or take certain other kinds of medicine or supplements during the study.

Background: PIEZO2 Deficiency Syndrome (PDS) is a genetic disorder that affects a person s ability to feel touches and pain. Researchers want to know more about how PDS changes nerve function. Objective: To compare nerve function in people with PDS to that in people without PDS. Eligibility: People aged 18 years and older with PDS enrolled in protocol 16-AT-0077. Healthy volunteers are also needed. Design: Participants will have at least 1 clinic visit. They will undergo a test that measures activity in the nerves. For the test: Participants will place their arm or leg in a comfortable position. Ultrasound will be used to locate nerves. A smooth wand will be slid over the skin to capture images of the structures below. Two thin needles will be inserted through the skin. These needles are much smaller than the kind used to draw blood. The needles will record nerve activity as different sensations are applied to the skin. These include mild electrical pulses; heat and cold; bending of the knee or elbow; vibration; air puffs; pulling a hair; and tapping, stroking (brushing), stretching, pinching, and pushing on the skin at different levels of force. Each test takes 5 to 10 minutes. Participants will describe the sensations they feel. Participants may opt for an additional test that measures how nerves respond after heat pulses are used to create mild redness on the skin. Researchers would like at least 2 tests from each person. Participants may return for up to 3 additional visits, if desired, to complete all the testing.

This pilot study will test an innovative way to establish how pain medicines provide analgesia in healthy adults. The study uses a group of short, controlled pain tests to look at different types of pain responses in the body. The main goal is to find out if this testing approach can show the pain-relieving effects of 2 medicines, pregabalin and naproxen versus placebo, and show how they provide relief of different types of pain. The study hypothesis is that this pain testing approach administered as a battery would be able to tell the difference between a medicine that works mainly in the brain and spinal cord (pregabalin) and a medicine that works mainly on inflammation in body tissues (naproxen). Up to 25 healthy adults will take part. Each participant will receive all 3 study treatments, pregabalin, naproxen, and placebo, administered in random order during separate study periods. The order will be assigned by chance. Neither the participant nor the study team will know which treatment is given at each visit. The study includes several experimental pain tests. These include: a heat and capsaicin skin test that causes short-term skin sensitivity, a UVB light test that causes a temporary sunburn-like sensitivity, and a cold pressor test, in which a hand is placed in very cold water for a short time. Participants will also have sensory testing to measure how they feel touch, pressure, pinprick, warmth, heat, and cold. Blood samples will be collected to measure study drug levels. Urine samples, vital signs, and other safety checks will also be done. Each treatment visit includes testing before and for several hours after taking the study drug. There will be a washout period of at least 48 hours between treatments. Total participation may last up to about 10 weeks. This study is not expected to provide direct medical benefit to participants. The information learned may help researchers improve early testing of future pain treatments....

This pilot study will test an innovative way to establish how pain medicines provide analgesia in healthy adults. The study uses a group of short, controlled pain tests to look at different types of pain responses in the body. The main goal is to find out if this testing approach can show the pain-relieving effects of 2 medicines, pregabalin and naproxen versus placebo, and show how they provide relief of different types of pain. The study hypothesis is that this pain testing approach administered as a battery would be able to tell the difference between a medicine that works mainly in the brain and spinal cord (pregabalin) and a medicine that works mainly on inflammation in body tissues (naproxen). Up to 25 healthy adults will take part. Each participant will receive all 3 study treatments, pregabalin, naproxen, and placebo, administered in random order during separate study periods. The order will be assigned by chance. Neither the participant nor the study team will know which treatment is given at each visit. The study includes several experimental pain tests. These include: a heat and capsaicin skin test that causes short-term skin sensitivity, a UVB light test that causes a temporary sunburn-like sensitivity, and a cold pressor test, in which a hand is placed in very cold water for a short time. Participants will also have sensory testing to measure how they feel touch, pressure, pinprick, warmth, heat, and cold. Blood samples will be collected to measure study drug levels. Urine samples, vital signs, and other safety checks will also be done. Each treatment visit includes testing before and for several hours after taking the study drug. There will be a washout period of at least 48 hours between treatments. Total participation may last up to about 10 weeks. This study is not expected to provide direct medical benefit to participants. The information learned may help researchers improve early testing of future pain treatments....

Background: Opioid drugs are often prescribed for acute and chronic pain. But these drugs are addictive, and they lead to more than 14,000 overdose deaths in the United States each year. Researchers want to find new drugs that relieve pain but are not addictive. This study will test whether a single dose of an experimental drug called (2R,6R)-hydroxynorketamine (HNK) can help reduce short term pain in healthy adults. HNK is related to ketamine. Studies suggest HNK might be as effective as ketamine at reducing pain but that it might have fewer side effects. In this study we will test how HNK affects pain and emotion. The results of this study may help us understand whether HNK has pain relieving effects and how it works in the brain, which could inform future pain treatments. Objective: To test the study drug \[(2R,6R)-hydroxynorketamine (HNK)\] for treating acute pain in healthy people. Eligibility: Healthy people aged 18 to 60 years. Design; Up to 92 healthy volunteers between 18 and 60 years old without chronic pain or psychiatric conditions will participate in the study. The study will take place at the NIH Clinical Center in Bethesda, Maryland. Each participant s involvement will last up to two months. The overall study is expected to last about three years (36 months). The study has 2 parts. In part 1, participants will have up to 2 clinic visits. They will be screened and have blood draws to make sure they're eligible for the study. They will complete sensory testing and have MRI brain scans. Sensory testing involves feeling and rating painful and non-painful sensations. These may include hot or cold temperatures, pinches or squeezes, and being touched with brushes or pinpricks. Eligible participants will have an imaging scan that shows brain activity: During the scan, they will rate heat, hear pleasant or unpleasant sounds, and view unpleasant or pleasant pictures. After completing part 1, eligible participants will be invited to part 2, which includes overnight stays at NIH. In part 2, participants will be assigned to either a treatment group or a no-treatment group. The treatment group will have 2 overnight visits of 2 nights each. The visits will be 1 to 3 weeks apart. For one of the visits, treatment group participants will receive the study drug HNK. For the other visit, they will receive a placebo. A placebo looks just like the study drug but contains no medicine. HNK and placebo are given through a tube inserted into a vein in the arm. The sensory tests, blood draws, and MRI scans will be repeated at each visit. Participants will not be told whether they got the drug or placebo on each visit. The nontreatment group will have 1 overnight visit. They will not receive the drug or placebo. The sensory tests, blood draws, and MRI scans will be repeated. Participants cannot drink alcohol, use recreational drugs, or take certain other kinds of medicine or supplements during the study.

Background: PIEZO2 Deficiency Syndrome (PDS) is a genetic disorder that affects a person s ability to feel touches and pain. Researchers want to know more about how PDS changes nerve function. Objective: To compare nerve function in people with PDS to that in people without PDS. Eligibility: People aged 18 years and older with PDS enrolled in protocol 16-AT-0077. Healthy volunteers are also needed. Design: Participants will have at least 1 clinic visit. They will undergo a test that measures activity in the nerves. For the test: Participants will place their arm or leg in a comfortable position. Ultrasound will be used to locate nerves. A smooth wand will be slid over the skin to capture images of the structures below. Two thin needles will be inserted through the skin. These needles are much smaller than the kind used to draw blood. The needles will record nerve activity as different sensations are applied to the skin. These include mild electrical pulses; heat and cold; bending of the knee or elbow; vibration; air puffs; pulling a hair; and tapping, stroking (brushing), stretching, pinching, and pushing on the skin at different levels of force. Each test takes 5 to 10 minutes. Participants will describe the sensations they feel. Participants may opt for an additional test that measures how nerves respond after heat pulses are used to create mild redness on the skin. Researchers would like at least 2 tests from each person. Participants may return for up to 3 additional visits, if desired, to complete all the testing.

Objective The current proposal investigates behavioral, psychophysiological, and social processes that may help explain biases and disparate outcomes in pain. Health disparities, or health outcomes that adversely affect disadvantaged populations, are pervasive and apparent in many diseases and symptoms, including pain. Pain is the number one reason individuals seek medical treatment. Health disparities in pain encompass both differences in pain experience and treatment for pain. For instance, research indicates that Black individuals report increased pain and have reduced pain tolerance relative to White individuals, yet doctors are less likely to treat minority patients pain and underestimate their pain experience. This project aims to address this systemic discrepancy by focusing on interpersonal processes that may contribute to these disparities, including socially-relevant responses to pain (i.e. pain expression) and pain assessment (e.g. visual attention). The proposed research aims to determine whether the study of pain expressions and their assessment can yield insights on how social factors shape pain and its treatment. Further, we test the efficacy of potential interventions designed to improve accuracy and reduce biases in pain assessment. If successful, this work will form the foundation of a new research program that will link the field of pain research with the field of social neuroscience, and forge new insights on the critical problem of health disparities in pain. Study population We will accrue up to 700 total healthy volunteers to target 240 completers Design Our overall aim is to understand how social factors influence the assessment and management of pain, and to gain insight into psychosocial processes that may underlie health disparities in pain. We propose a series of studies designed to test these links. First, we will measure pain perception and physiological responses to painful stimuli in a diverse group of individuals to test for sociocultural and biological influences on pain and pain-related responses. In subsequent studies, new participants ("perceivers") will view images of these initial participants ("targets") and will provide estimates of 'targets' pain experience. We will measure a) whether perceivers can accurately estimate 'targets' pain experience; b) whether accuracy differs as a function of similarity between target and perceiver (ingroup vs outgroup); and c) whether individuals can improve accuracy through feedback. Outcome measures Primary outcome measures for all experiments will be decisions about pain (experienced by self or other) measured with visual analogue scales, reaction time, and/or categorical judgments (pain/no pain). We will also measure physiological responses (e.g., facial muscle response, skin conductance, pupil dilation) and brain responses using functional magnetic resonance imaging (fMRI) as secondary outcome measures. We will test whether pain and pain-related responses varies as a function of sociocultural/demographic factors (e.g. race, ethnicity, sex) and whether accuracy in assessing others' pain is influenced by group similarity (i.e. ingroup vs. outgroup) and training (e.g. performance-related feedback)....

Background: \- Painful stimuli cause changes in a network of brain regions called the "Pain Matrix." But most of these regions respond to many other stimuli, not just pain. Researchers want to understand how different factors influence pain. They want to test what happens when people expect different levels of pain and receive treatments that can modify pain. They want to see if these factors influence decisions about pain and how the body responds to it. They also want to compare pain with responses like taste and vision. Objectives: \- To better understand how pain and emotions are processed and influenced by psychological factors. Eligibility: \- Healthy volunteers ages 18-50. Design: * This study requires 1 to 2 clinic visits that last 1 to 3 hours. * Participants will be screened with medical history and physical exam. * Some participants will have one or more magnetic resonance imaging (MRI) scans of their brain. For MRI, participants will lie on a table that slides in and out of a cylinder. The scanner makes loud knocking noises. They will get earplugs. * Participants' heart activity will be recorded with electrocardiogram. Their pulse, sweating, and breathing will be monitored. * Some participants will take a taste test. Others may perform simple tasks. Others may receive pain in their arm, leg, or hand. The pain will come from heat or electric shocks. Others may judge pain using a topical pain-relieving cream. Some of these tests may be given during MRI. * Participants will fill out questionnaires. * The study will last 3 years.

Background: Researchers want to better understand pain by studying people with and without different kinds of pain. To do this, researchers will expose people to pleasant and unpleasant sensations. They will ask them questions about their pain. Researchers also want to see if these people are eligible for other research studies at the National Center for Complementary and Integrative Health. Objectives: To study the experience of pain. Also to find people eligible to join other NIH studies. Eligibility: People 12 years and older with and without pain disorders. Design: Participants will be screened by phone. Participants will have one required visit lasting about 2 hours. This may include: * Medical history * Physical exam * Questionnaires about themselves and their pain experience * Blood and urine tests * MRI: They will lie on a table that slides into a cylinder. They will feel different sensations while completing tasks on a computer. This lasts 15 minutes to 2 hours. * Quantitative sensory testing: They will be exposed to different pictures, sounds, tastes, and smells. They will also be exposed to pleasant and unpleasant sensations. These could include: * Burning, itching, or cold sensations * Pinpricks * Pressure and pinches * Electrocardiogram: Stickers on the chest record heart activity. * Straps placed around the chest to measure breathing. * Small sensors on the fingers or palms to measure pulse and sweating. Participants may have up to 12 other outpatient study visits. Participants may be recorded at the visits.

Background: The vagus nerve runs from the brain to many organs. Stimulating it can affect the experience of pain. The nerve can be stimulated on the surface of the left ear. Researchers want to study how this stimulation affects the perception of pain. They also want to study how mood affects the experience of pain. Objective: To study the effects of mood and vagus nerve stimulation on the experience of pain. Eligibility: Healthy people ages 18 and older who are fluent in English Design: Participants will be pre-screened with a 15-minute phone call. Participants will have three 2-hour visits. At the screening visit, participants will be screened with: Medical and psychiatric history Physical and psychological exams Questionnaires about physical and psychiatric health and mood Urine tests A heat probe on the forearm. The temperature will be increased until it is painful but tolerable. Participants will have 2 testing sessions within 7 days. Before the testing, they cannot do the following: Eat, use nicotine, or exercise for at least 2 hours Drink alcohol for 24 hours Take certain medicines for 3 days Testing includes: Urine drug screening Left ear stimulation: In one session, the vagus nerve will be stimulated. In the other, an area of the ear away from the vagus nerve will be stimulated. This will be done with mild electric shocks that cause a tingling, pricking, or itchy feeling. Heat applied to the forearm until it is painful but tolerable Completing several forms on a computer or on paper about how they are feeling Monitors on the chest and a finger clip to monitor heart, breathing, and blood pressure