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

37 Participants Needed

Trial Summary

What is the purpose of this trial?

This trial tests if guanfacine can make lidocaine more effective in reducing facial pain for patients with trigeminal neuralgia by making the pain relief last longer. Guanfacine is primarily used for treating ADHD and has been found to help with symptoms in children.

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.

What data supports the effectiveness of the drug combination of Guanfacine and Lidocaine for trigeminal neuralgia?

Research shows that combining pharmacotherapy with a lidocaine block can reduce pain episodes and improve general health and depression in trigeminal neuralgia patients. Additionally, lidocaine has been found effective in reducing pain intensity and maintaining therapeutic results for 24 hours after infusion. ^{1 2 3 4 5}

Is the combination of Guanfacine and Lidocaine safe for treating trigeminal neuralgia?

Lidocaine is generally safe with minimal risk for systemic toxicities when used as a patch, but it can cause mild skin reactions. However, when used intravenously, it may cause neuropsychiatric and cardiological side effects. There is no specific safety data available for the combination of Guanfacine and Lidocaine. ^{1 3 6 7 8}

How does the drug Guanfacine + Lidocaine differ from other treatments for trigeminal neuralgia?

The combination of Guanfacine and Lidocaine for trigeminal neuralgia is unique because it pairs an existing pain relief method (Lidocaine) with Guanfacine, which is not typically used for this condition. Lidocaine is often used intravenously or as an aerosol for acute pain relief, but combining it with Guanfacine could offer a novel approach to managing pain, potentially enhancing effectiveness or reducing side effects compared to standard treatments like carbamazepine. ^{1 2 3 4 9}

Research Team

Tigran Kesayan, MD

Principal Investigator

Vanderbilt University Medical Center

Eligibility Criteria

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

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

Treatment Details

Interventions

• Guanfacine
• Lidocaine

Participant Groups

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+

Findings from Research

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]

References

1. Germany pubmed.ncbi.nlm.nih.gov

Combination of pharmacotherapy and lidocaine analgesic block of the peripheral trigeminal branches for trigeminal neuralgia: a pilot study. [2016]

2. United States pubmed.ncbi.nlm.nih.gov

Pharmacotherapy of trigeminal neuralgia. [2019]

3. England pubmed.ncbi.nlm.nih.gov

Lidocaine aerosol sprayed on oral and/or nasal mucosa for the rescue of acute trigeminal neuralgia exacerbations: A retrospective study. [2023]

4. Egypt pubmed.ncbi.nlm.nih.gov

The Effect of Intravenous Lidocaine on Trigeminal Neuralgia: A Randomized Double Blind Placebo Controlled Trial. [2022]

5. England pubmed.ncbi.nlm.nih.gov

Drug therapy of trigeminal neuralgia. [2006]

6. England pubmed.ncbi.nlm.nih.gov

Neuropsychiatric side-effects of lidocaine: examples from the treatment of headache and a review. [2013]

7. England pubmed.ncbi.nlm.nih.gov

Safety and tolerability of the lidocaine patch 5%, a targeted peripheral analgesic: a review of the literature. [2019]

8. United States pubmed.ncbi.nlm.nih.gov

Drugs used in the management of trigeminal neuralgia. [2019]

9. United States pubmed.ncbi.nlm.nih.gov

Failure of mexiletine to control trigeminal neuralgia. [2019]