Efficacy of Guanfacine and Lidocaine Combination in Trigeminal Nerve Block for Pain Management in Trigeminal Neuropathy

Phase 2

Completed

Conditions: Trigeminal Neuralgia

Interventions: Drug: Lidocaine
Drug: Guanfacine

Registration Number: NCT03865940

Lead Sponsor: Vanderbilt University Medical Center

Brief Summary: A phenome-wide association study (PheWAS) identified an association between a loss of function variant in the human alpha 2B adrenergic receptor gene and trigeminal nerve disorders. Guanfacine is the oldest alpha-2 adrenergic agonist in clinical use and is approved for hypertension and attention deficit hyperactivity disorder. We hypothesize that guanfacine will be an effective adjunct to lidocaine for the treatment of neuropathic pain by enhancing and prolonging pain relief due to its activation of alpha-2 adrenergic receptors. The objectives of the study will be to evaluate the efficacy and safety of guanfacine in combination with lidocaine for trigeminal nerve block procedures for pain management in trigeminal neuralgia patients. This study will evaluate the efficacy of guanfacine in reducing acute pain and extending duration of pain relief when delivered in combination with lidocaine as a trigeminal nerve block, measured by Visual Analog Scale (VAS) data collected at specific time points after each injection.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 37

Inclusion Criteria

Ability to understand and read English
History of painful trigeminal neuropathy with persistent background facial pain severity > 5/10 on VAS
Experience pain with a score of greater than 5 on a 0-10 scale (VAS) in the previous 24 hours before procedural treatment and at the time of procedural treatment.
Eligible for trigeminal nerve block procedure and have not had a trigeminal nerve block procedure for pain management prior to the enrollment in the current study.
Able to provide informed consent.

Exclusion Criteria

Presence of a significant structural lesion (e.g., tumor) as the cause of pain as shown in at least one neuroimaging study.
Current diagnosis of fibromyalgia, temporomandibular disorders (TMD), odontogenic pain or other orofacial pain deemed unrelated to the trigeminal nerve as the origin.
Allergy or any other hypersensitivity reactions to guanfacine or lidocaine or local anesthetic of the amide type, or to both iodinated contrast and gadolinium contrast.
Females who are pregnant or breastfeeding and/or plan to become pregnant or to breastfeed during study participation.
Participation in another investigational drug study within 30 days before randomization.
Inability to understand the requirements of the study, inability to abide by the study restrictions, inability to fill out the questionnaires, or inability to return for the required treatments.
Any clinically significant medical or surgical condition that in the investigator's opinion could interfere with the administration of study drug, interpretation of study results, or compromise the safety or well-being of the subject (i.e. infection, unable to stop anticoagulants).
No reliable access to telephone service to allow for contact with study personnel.

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Lidocaine then Lidocaine + Guanfacine	Guanfacine	Trigeminal nerve block will be performed with injection of 6 mL of 1% lidocaine (Day 1). Patient will return between Day 15-28 and trigeminal nerve block will be performed with injection of 6 mL of 1% lidocaine + 250 mcg guanfacine.
Lidocaine then Lidocaine + Guanfacine	Lidocaine	Trigeminal nerve block will be performed with injection of 6 mL of 1% lidocaine (Day 1). Patient will return between Day 15-28 and trigeminal nerve block will be performed with injection of 6 mL of 1% lidocaine + 250 mcg guanfacine.
Lidocaine + Guanfacine then Lidocaine	Lidocaine	Trigeminal nerve block will be performed with injection of 6 mL of 1% lidocaine + 250 mcg guanfacine (Day 1). Patient will return between Day 15-28 and trigeminal nerve block will be performed with injection of 6 mL of 1% lidocaine.
Lidocaine + Guanfacine then Lidocaine	Guanfacine	Trigeminal nerve block will be performed with injection of 6 mL of 1% lidocaine + 250 mcg guanfacine (Day 1). Patient will return between Day 15-28 and trigeminal nerve block will be performed with injection of 6 mL of 1% lidocaine.

Primary Outcome Measures

Name	Time	Method
Time to Return to Baseline Pain After Injection.	up to 2 weeks	Time (hours) until pain returns to baseline number.

Secondary Outcome Measures

Name	Time	Method
Pain Intensity in Follow-Up	8 hours	Pain Intensity after treatment measured throughout the 8-hour follow-up period on a visual analog scale (VAS) from 0 to 10, where 0 is the least pain and 10 is the most pain.
Frequency of Nerve Pain Attacks	14 days	Frequency of nerve pain attacks during the 14-day follow-up period. Pain frequency was recorded numerically as 0 - None (no pain), 1 - Weekly, 2 - Daily, 3 - Hourly, and 4 - Constant pain. Data was not collected at baseline, only at Day 7 and Day 14.
Rescue Medication Use	8 hours	Number of participants using rescue medication during the 8-hour follow-up period
Time to First Rescue Medication	14 days	Time, in hours, to use of first rescue medication in the follow-up period following the injection.
Quality of Life, Physical Health	14 days	Participant Quality of Life as measured by the PROMIS Global Health -10 SF during the 14-day follow-up. The scores reported are T-scores. The T-score rescales the raw sum score into a standardized score with a mean of 50 and a standard deviation (SD) of 10. Therefore a person with a T-score of 40 is one SD below the mean and a person with a T-score of 60 is one SD above the mean. For the Physical Health subscale, raw scores are converted into t-scores ranging from 16.2 to 67.7 and higher t-scores are indicative of better overall physical health.
Quality of Life, Mental Health	14 days	Participant Quality of Life as measured by the PROMIS Global Health -10 SF during the 14-day follow-up. The scores reported are T-scores. The T-score rescales the raw sum score into a standardized score with a mean of 50 and a standard deviation (SD) of 10. Therefore a person with a T-score of 40 is one SD below the mean and a person with a T-score of 60 is one SD above the mean. In this Mental Health subscale, raw scores are converted into t-scores ranging from 21.2 to 67.6, where higher t-scores are indicative of better overall physical health.