Guanfacine + Lidocaine for Trigeminal Neuralgia

Overseen By Patricia Hendricks, RN, CCRP

Age: 18+

Sex: Any

Trial Phase: Phase 2

Sponsor: Vanderbilt University Medical Center

Disqualifiers: Fibromyalgia, TMD, Pregnancy, others

Stay on Your Current Meds You can continue your current medications while participating

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 9

Duration: 4 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a combination of two drugs, guanfacine and lidocaine, to determine if they can better manage pain from trigeminal neuralgia, a condition causing severe facial pain. Researchers aim to discover whether adding guanfacine to lidocaine extends and enhances pain relief. Individuals with a history of severe, persistent facial pain who have not previously undergone a trigeminal nerve block might be suitable candidates for this trial. As a Phase 2 trial, the research focuses on measuring the treatment's effectiveness in an initial, smaller group of participants.

Will I have to stop taking my current medications?

The trial information does not specify if you need to stop taking your current medications. However, if you are on anticoagulants (blood thinners), you may need to stop them as the study mentions that inability to stop anticoagulants could be a concern.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that using guanfacine with lidocaine might be safe for treating trigeminal neuralgia, a type of facial pain. In earlier studies, participants who took this combination did not experience any serious side effects. Guanfacine, already used for high blood pressure and ADHD, appears to work well with lidocaine. This combination resulted in lower pain levels compared to using lidocaine alone. These findings suggest that the mix of lidocaine and guanfacine is well-tolerated and could effectively help manage pain. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about these treatments for trigeminal neuralgia because they combine lidocaine with guanfacine, potentially offering a new way to manage pain. Unlike standard treatments like anticonvulsants and antidepressants which primarily affect nerve signals and mood, this combination treatment involves a direct nerve block with lidocaine to numb the area, while adding guanfacine aims to enhance pain relief by modulating nerve activity. The alternating sequences of lidocaine with and without guanfacine in different treatment arms allow researchers to assess the added benefit of guanfacine in controlling pain more effectively. This unique approach could lead to quicker pain relief and better outcomes for patients suffering from this intense facial pain condition.

What evidence suggests that this trial's treatments could be effective for trigeminal neuralgia?

Research has shown that using guanfacine with lidocaine can greatly reduce pain for people with trigeminal neuralgia. In this trial, one group of participants will receive a trigeminal nerve block with a combination of lidocaine and guanfacine, while another group will initially receive lidocaine alone, followed by the combination later. Studies found that patients who received this combination reported less pain in the hours after the injection compared to those who only received lidocaine. Guanfacine, typically used to treat high blood pressure and ADHD, may help by activating certain receptors that enhance pain relief. This combination not only lessens immediate pain but also prolongs relief. These findings suggest a promising way to manage pain for trigeminal neuralgia patients. ^{1 3 4 5 6}

Who Is on the Research Team?

Tigran Kesayan, MD

Principal Investigator

Vanderbilt University Medical Center

Are You a Good Fit for This Trial?

Inclusion Criteria

Able to provide informed consent

You have a history of persistent facial pain rated above 5 out of 10 on a pain scale.

You are able to have a nerve block procedure for pain and have not had this procedure before joining the study.

Exclusion Criteria

Participation in another investigational drug study within 30 days before randomization

Females who are pregnant or breastfeeding and/or plan to become pregnant or to breastfeed during study participation

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

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Trigeminal nerve block with lidocaine and guanfacine or lidocaine alone, followed by crossover

4 weeks

2 visits (in-person)

Follow-up

Participants are monitored for pain intensity, quality of life, and rescue medication use

2 weeks

Follow-up assessments at Day 7 and Day 14

What Are the Treatments Tested in This Trial?

Interventions

• Guanfacine
• Lidocaine

How Is the Trial Designed?

Group I: Lidocaine then Lidocaine + Guanfacine Experimental Treatment 2 Interventions

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.

Group II: Lidocaine + Guanfacine then Lidocaine Experimental Treatment 2 Interventions

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 is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Lidocaine for:

• Local anesthesia for minor surgical procedures
• Surface anesthesia for minor procedures
• Spinal anesthesia
• Epidural anesthesia

Approved in European Union as Lidocaine for:

• Local anesthesia
• Regional anesthesia
• Surface anesthesia

Approved in Canada as Lidocaine for:

• Local anesthesia
• Regional anesthesia

Who Is Running the Clinical Trial?

Vanderbilt University Medical Center

Lead Sponsor

Trials

922

Recruited

939,000+

Published Research Related to This Trial

Carbamazepine is the primary treatment for trigeminal neuralgia, showing significant efficacy with a number needed to treat (NNT) of 1.7 for at least 50% pain relief, making it a highly effective option.

Other medications like baclofen and lamotrigine also provide pain relief, with baclofen having an NNT of 1.4, while lamotrigine can enhance relief for patients not fully helped by carbamazepine or phenytoin (NNT = 2.1).

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Pharmacotherapy of trigeminal neuralgia. Sindrup, SH., Jensen, TS.[2019]

Carbamazepine and lamotrigine are the most effective medications for treating trigeminal neuralgia, with baclofen also showing some effectiveness, highlighting the need for effective treatments with manageable side effects.

While drug therapy helps most patients, some may need additional nonpharmacological treatments, and future approaches like neuromodulation could offer new options for managing this chronic pain syndrome.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Drug therapy of trigeminal neuralgia. Canavero, S., Bonicalzi, V.[2006]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12491861/

insights from a PheWAS-guided randomized controlled study (A) Average NRS pain scores over the first 8 h post injection. NRS pain scores were significantly lower in participants receiving lidocaine + 250 µg guanfacine.

2. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/40326696/

Enhanced Pain Relief with Guanfacine as an Adjuvant for ... Results: NRS pain scores over the first 8 hours post-injection were significantly lower in the interventional group (guanfacine + lidocaine) ...

3. vanderbilt.trialstoday.org vanderbilt.trialstoday.org/trial/NCT03865940

Efficacy of Guanfacine and Lidocaine Combination ... This study will evaluate the efficacy of guanfacine in reducing acute pain and extending duration of pain relief when delivered in combination with lidocaine ...

4. aging.networkofcare.org aging.networkofcare.org/sanmateo/CommunityResources/ClinicalTrials/Detail/NCT03865940?keyword=%22Neuralgia%22

San Mateo Clinical Trial Efficacy of Guanfacine and ... 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 ...

5. researchgate.net researchgate.net/publication/391488209_Enhanced_Pain_Relief_with_Guanfacine_as_an_Adjuvant_for_Trigeminal_Nerve_Blocks_Insights_from_a_PheWAS-Guided_Randomized_Controlled_Study

(PDF) Enhanced Pain Relief with Guanfacine as an ... NRS pain scores were significantly lower in participants receiving lidocaine þ 250 µg guanfacine. (B) Average NRS pain scores from baseline to ...

6. cdn.clinicaltrials.gov cdn.clinicaltrials.gov/large-docs/40/NCT03865940/Prot_SAP_001.pdf

Last updated: 03/07/2022 1 The safety and tolerability of a single dose of guanfacine in combination with lidocaine compared to lidocaine alone. Background: Painful trigeminal ...