Genetic Basis For Variation In NSAID Analgesia In A Clinical Model Of Acute Pain
Status:
Completed
Trial end date:
2006-10-04
Target enrollment:
Participant gender:
Summary
This study will evaluate how genetic makeup contributes to the variation in people regarding
their sensitivity to and experience of pain. Scientists believe that differences in
information found in genes may explain why an analgesic drug, that is, one that treats pain,
works effectively for some people but not for others. The study will explore pain that is
acute (fast and short period). Knowledge gained from this ongoing study may permit
development of an individualized analgesic drug prescription.
Patients ages 16 to 35 who are in good health and have been referred for removal of impacted
wisdom teeth; who are not allergic to aspirin or other nonsteroidal anti-inflammatory drugs
(known as NSAIDs), sulfites, or certain anesthetics; who are not pregnant or nursing; and who
are willing to have a biopsy before and after dental surgery are eligible for this study.
Patients will come to the clinic for one test visit and one treatment visit. During the first
visit, a questionnaire will evaluate patients' psychological state, including mood and
depression. There will be a clinical examination of their wisdom teeth. A blood sample of 10
milliliters (about 0.4 ounces) will be collected from the forearm to provide DNA material
containing genes stored in cells. The primary genetic analysis will be done at NIH, although
the DNA collected might also be sent to a laboratory outside NIH. DNA samples will be coded
so that names of patients cannot be traced.
During the second visit, two of the patients' lower wisdom teeth will be removed. Patients
will be given a local anesthetic in the mouth and a sedative given through a vein in the arm.
While the mouth is numb, a small piece of tissue will be removed from inside the cheek, near
the wisdom tooth. It is the first biopsy. After the two wisdom teeth are removed, a small
piece of tubing will be placed into both sides of the mouth where the teeth were removed.
Every 20 minutes, for the next 3 hours, the researchers will collect inflammatory fluid from
the tubing, to measure the chemicals thought to cause pain and swelling. Also every 20
minutes, patients will rate the pain they feel by answering questions. If there is pain
before 3 hours following surgery, they will receive a dose of fentanyl to relieve moderate to
severe pain. A second biopsy will occur 3 hours after surgery, to measure changes in
chemicals produced in response to surgery. Immediately afterward, patients will receive 30 mg
of ketorolac (Toradol) whether or not pain is felt. They will answer questionnaires about
pain for 3 hours after receiving the drug, to rate how well it works. They will stay at the
clinic up to 6 hours after the surgery. If pain is not relieved with ketorolac, patients will
receive a one-time dose of tramadol, a pain medication for moderate to severe pain. After the
study procedures are completed, patients will receive pain medication for pain after surgery.
Patients will be monitored closely, because all drugs have side effects. Ketorolac is a
nonsteroidal anti-inflammatory drug, one that may cause gastrointestinal upset. Fentanyl is a
powerful narcotic drug that is safe at the dosage used in this study, but stomach upset,
dizziness, and breathing trouble may occur. Also, risks from the biopsy include discomfort
from injecting the numbing medicine, infection, and bleeding. There may be discomfort from
the sedative injected into the vein, and there may be bruising.
Benefits from participating are having wisdom teeth removed at no cost as well as close
monitoring before and after surgery. There are no plans to give patients the results of
genetic tests or questionnaires. Years of research may be needed before such information has
the chance to become meaningful.