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Phenytoin as Treatment for Acute Exacerbations of Trigeminal Neuralgia - a Prospective Systematic Study of 20 Patients

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03712254
Recruitment Status : Recruiting
First Posted : October 19, 2018
Last Update Posted : June 24, 2020
Information provided by (Responsible Party):
Lars Bendtsen, Danish Headache Center

Brief Summary:

The nature of trigeminal neuralgia (TN) is fluctuating and patients can experience periods of complete remission of pain as well as periods with excessive pain. TN is often triggered by innocuous intra- and extraoral stimuli such as chewing. Since the first-line prophylactic drugs, i.e. carbamazepine and oxcarbazepine, are administered orally, medical treatment of TN can be problematic in periods of exacerbation. In cases of severe exacerbation, patients oftentimes become dehydrated and anorectic as eating and drinking will evoke pain. Treatment with drugs administered intravenously is needed in such situations. Phenytoin was the first drug to be used for TN but it is rarely used as long-time preventative because of frequent side-effects associated with long-term use. However, phenytoin has the advantage over other drugs, that it can be administered also intravenously as fosphenytoin (the prodrug of phenytoin).

By clinical experience the efficacy is very good. However, evidence of the treatment is lacking as only case reports including a total of 5 patients described the effects and side effects with pain relief lasting two days. By providing solid observational evidence, the treatment can be considered for incorporation in local and international treatment guidelines.

The aim of the study is to test the hypothesis that fosphenytoin loading reduces TN pain with at least 50 % in 80% of patients with trigeminal neuralgia experiencing exacerbation of TN pain.

The study is a descriptive prospective observational pilot study with 3 months followup period.

Condition or disease Intervention/treatment
Trigeminal Neuralgia Drug: Fosphenytoin

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Study Type : Observational [Patient Registry]
Estimated Enrollment : 20 participants
Observational Model: Cohort
Time Perspective: Prospective
Target Follow-Up Duration: 3 Months
Official Title: Phenytoin as Treatment for Acute Exacerbations of Trigeminal Neuralgia - a Prospective Systematic Study of 30 Patients
Actual Study Start Date : November 1, 2018
Estimated Primary Completion Date : January 1, 2022
Estimated Study Completion Date : April 1, 2022

Resource links provided by the National Library of Medicine

Intervention Details:
  • Drug: Fosphenytoin
    Patients with trigeminal neuralgia that due to acute exacerbations of trigeminal neuralgia pain are admitted for fosphenytoin loading are the subjects of interest.

Primary Outcome Measures :
  1. Degree of acute pain relief [ Time Frame: Primary outcome is measured app. 24 hours after fosphenytoin loading. ]
    Degree of pain relief measured by the verbal numeric rating scale of pain 24 hours after treatment compared with 24 hours before treatment.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients with trigeminal neuralgia admitted for fosphenytoin loading due to acute exacerbations of trigeminal neuralgia pain.

Inclusion Criteria:

  • Age 18 years or older.
  • Must be able to give signed informed consent prior to study entry.
  • Must fulfill the ICHD-3 diagnostic criteria for TN. Both patients with purely paroxysmal TN and patients with TN with concomitant persistent facial pain will be included.
  • MRI of the brain, brainstem and trigeminal nerve or patient is willing to undergo MRI in the days and weeks following admission.
  • Must be able to adhere to the study protocol and understand either Danish or English.

Exclusion Criteria:

  • Psychiatric or mental illness or condition that might interfere with the ability of the patients to fill in the Informed Consent.
  • Contraindications for phosphenytoin loading such as sick sinus syndrome, atrioventricular block and hepatic insufficiency.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03712254

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Contact: Lars Bendtsen, MD, PhD, Dr Med Sci +4538633065
Contact: Anne Sofie Schott Andersen, MD, PhD Dr. Med Sci +4538632330

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Danish Headache Center, Rigshospitalet - Glostrup Recruiting
Glostrup, Denmark, 2600
Contact: Lars Bendtsen, MD, PhD, Dr Med Sci    +4538633065   
Sponsors and Collaborators
Danish Headache Center
Additional Information:

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Responsible Party: Lars Bendtsen, Associate professor, Danish Headache Center Identifier: NCT03712254    
Other Study ID Numbers: H-18023737
First Posted: October 19, 2018    Key Record Dates
Last Update Posted: June 24, 2020
Last Verified: June 2020

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Lars Bendtsen, Danish Headache Center:
acute pain, fosphenytoin
Additional relevant MeSH terms:
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Trigeminal Neuralgia
Peripheral Nervous System Diseases
Neuromuscular Diseases
Nervous System Diseases
Neurologic Manifestations
Signs and Symptoms
Trigeminal Nerve Diseases
Facial Neuralgia
Facial Nerve Diseases
Mouth Diseases
Stomatognathic Diseases
Cranial Nerve Diseases
Sodium Channel Blockers
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action