Tizanidine
| Evidence Level: L5 | Predicted Indications: 6 |
Table of Contents
Tizanidine: From Spasticity Management to Migraine Disorder
One-Sentence Summary
Tizanidine is a centrally acting alpha-2 adrenergic agonist, which is a muscle relaxant class. The TxGNN model predicts it may be effective for migraine disorder, with 2 registered clinical trials (only 1 directly relevant) and 16 publications currently supporting this direction. Tizanidine’s original FDA-labelled indication is not available in the data compiled for this report. The spasticity use mentioned here comes from general drug knowledge, not from the compiled data.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not available in the compiled data (general knowledge: spasticity) |
| Predicted New Indication | Migraine disorder |
| TxGNN Prediction Score | 99.79% |
| Evidence Level | L1 (provisional; see note below) |
| US Market Status | Cancelled only (no currently valid licenses) |
| Number of NDAs | 9 (all ANDA generic applications, all cancelled) |
| Recommended Decision | Proceed with Guardrails |
Note on the evidence level: L1 normally requires at least 2 completed Phase 3 RCTs. The only Phase 3 trial (NCT05484349) has an “Unknown” status with no reported results, so L1 is provisional and should be verified against published trial results. Strictly by the rules, the evidence would be closer to L2 or L3: the one placebo-controlled RCT (2002) was in chronic daily headache, not strictly migraine.
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available in the compiled data. Based on known pharmacology, tizanidine is a central alpha-2 adrenergic agonist. Alpha-2 agonism can reduce trigeminovascular pain signalling and central sensitization, and may lower the muscle tension that contributes to headache. These effects give a plausible basis for migraine and chronic daily headache prevention.
Migraine and chronic daily headache share pain-processing pathways that tizanidine may modulate. A double-blind, placebo-controlled, multicentre study (PMID 12167135, 2002) tested tizanidine as add-on prevention in chronic daily headache (chronic migraine, migrainous headache or tension-type headache). Several reviews also list tizanidine among options studied for migraine prevention.
Caveats:
- The Phase 3 trial of tizanidine for migraine prevention has no reported results.
- The 2002 study covers chronic daily headache, not strictly migraine.
- Several of the supporting publications are general reviews that mention tizanidine only briefly.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT05484349 | Phase 3 | Unknown | 189 | Multicentre, randomized, double-blind, placebo-controlled study of oral tizanidine for preventing migraine attacks in adults aged 18–65 with episodic migraine. Directly relevant, but no results are available. |
| NCT02403687 | N/A | Completed | 300 | 24-week observational study of topical NSAIDs for pain relief. It does not mention tizanidine or migraine, so relevance is low. |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 12167135 | 2002 | RCT | Headache | Double-blind, placebo-controlled multicentre study of tizanidine versus placebo as add-on prevention in chronic daily headache |
| 11318882 | 2001 | Open-label study | Headache | Dose-titration study of tizanidine efficacy and tolerability for chronic daily headache prevention |
| 11903539 | 2002 | Clinical study | Headache | Low-dose tizanidine with NSAIDs for detoxification from analgesic rebound headache |
| 12696998 | 2003 | Review | CNS Drugs | Muscle-tone drugs (baclofen, tizanidine, botulinum toxin A) as migraine and tension-type headache prevention. Well-controlled data are sparse, and botulinum toxin has the most data. |
| 15115635 | 2004 | Review | Current Pain and Headache Reports | Emerging migraine prevention options, including tizanidine |
| 20464578 | 2010 | Review | Neurological Sciences | Review of double-blind placebo-controlled trials of chronic migraine prophylaxis |
| 31365643 | 2019 | Consensus guideline | Arquivos de Neuro-Psiquiatria | Brazilian Headache Society consensus on chronic migraine treatment |
| 17115988 | 2006 | Review | Headache | Prophylactic treatment of chronic daily headache; tizanidine is among the agents evaluated |
| 21770931 | 2011 | Review | Headache | Clinical trials on medication overuse and prophylaxis; tizanidine is among the agents evaluated |
| 40983294 | 2025 | Preclinical/formulation | Journal of Controlled Release | Tizanidine–meloxicam supramolecular self-assembly designed to enhance anti-migraine efficacy |
US Market Information
All 9 US authorizations are generic (ANDA) applications and all are cancelled. The approved indication text is not available in the compiled data.
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| ANDA091283 | Tizanidine (Proficient Rx LP) | Tablet | Not available |
| ANDA076416 | Tizanidine (Bryant Ranch Prepack) | Tablet | Not available |
| ANDA078868 | Tizanidine Hydrochloride (AvKARE) | Capsule, gelatin coated | Not available |
| ANDA210021 | Tizanidine Hydrochloride (Nivagen Pharmaceuticals) | Capsule | Not available |
| ANDA076286 | Tizanidine (AvPAK) | Tablet | Not available |
Four more cancelled ANDAs exist (ANDA208187, ANDA213798, ANDA076533, ANDA212196). Available oral forms are tablets and capsules.
Safety Considerations
- Disease-related cautions (from the knowledge graph, not label text): Contraindication links exist with liver failure, kidney disease, pyoureter, psychotic disorders (including schizophreniform and schizoaffective disorders), other mental disorders, and hypotensive disorder.
- Drug Interactions: 100 interactions were found. Examples from the first 20 listed:
- Major: famotidine, morphine, cimetidine, dolasetron, obeticholic acid
- Moderate: hyoscyamine, loperamide, atropine, clarithromycin, dicyclomine, palonosetron, naltrexone, levofloxacin, metoclopramide, and others
- Additional guardrails noted in the evaluation: sedation, hypotension, and hepatotoxicity (monitor liver enzymes). Strong CYP1A2 inhibitors such as fluvoxamine and ciprofloxacin are contraindicated.
Please refer to the package insert for full warnings and contraindications, as label text was not available in the compiled data.
Other Predicted Indications (Brief)
| Predicted Indication | Score | Evidence Level | Recommendation | Comment |
|---|---|---|---|---|
| Migraine with brainstem aura | 99.71% | L4 | Hold | Only a breast-feeding recommendation review; no efficacy evidence |
| Migraine with or without aura, susceptibility to | 99.54% | L3 | Research Question | Overlaps with migraine disorder; the literature is the same indirect set |
| Atrophoderma vermiculata | 99.31% | L5 | Hold | Model prediction only |
| Tourette syndrome | 99.17% | L4 | Hold | Class-level rationale from alpha-2 agonists; no specific data |
| Ulerythema ophryogenesis | 99.13% | L5 | Hold | Model prediction only |
Conclusion and Next Steps
Decision: Proceed with Guardrails
Rationale: A directly relevant Phase 3 placebo-controlled trial in migraine prevention exists, along with a placebo-controlled RCT in chronic daily headache and a plausible alpha-2 mechanism. However, the Phase 3 trial has no reported results and an unknown status. The L1 level is therefore provisional, and the interaction burden is large.
To proceed, the following is needed:
- Verify the results and current status of NCT05484349
- Obtain FDA package insert warnings, contraindications and original indication text (currently missing)
- Obtain detailed mechanism of action data from DrugBank
- Confirm current US market availability, since all 9 ANDAs are cancelled
- Define a safety monitoring plan covering sedation, hypotension, liver enzymes, and CYP1A2 inhibitor exclusion
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.