Tolfenamic Acid

Evidence Level: L5

Predicted Indications: 9

Tolfenamic Acid

Pharmacist Assessment Report

Tolfenamic Acid: From an Unspecified Labelled Indication to Headache Disorder

One-Sentence Summary

Tolfenamic acid is an NSAID marketed in India as Clotan Capsule. The approved indication text is not available in the data compiled for this report, but its published use is in migraine and rheumatic disease. The TxGNN model predicts it may be effective for headache disorder, with no registered clinical trials but 19 publications (including several randomised double-blind studies in migraine) supporting this direction.

Quick Overview

Item	Content
Original Indication	Not stated in the available India licence data
Predicted New Indication	Headache disorder
TxGNN Prediction Score	0.9974
Evidence Level	L5 (see note below)
India Market Status	Listed in a compiled Indian medicine price dataset (1 of 1) – CDSCO approval status is not included in this data
Number of Listed Products	1 (valid: 1)
Recommended Decision	Proceed with Guardrails

Note on evidence level: The literature includes several randomised double-blind trials in migraine (1979–2004), but none is a registered Phase 3 trial, so L1 rests on published RCTs rather than on the strict “two completed Phase 3 RCTs” definition. No clinical trial registry records are available.

Why is This Prediction Reasonable?

Detailed mechanism-of-action data is not available in the compiled data. Based on known information, tolfenamic acid is an NSAID of the fenamate class. It inhibits cyclooxygenase and reduces prostaglandin synthesis, and it has also been reported to affect leukotriene pathways.

Prostaglandins sensitise nociceptors and are involved in platelet aggregation, vasodilatation and neurogenic inflammation, all of which are implicated in migraine. This makes a prostaglandin-inhibiting drug a plausible treatment for headache disorders.

One practical consideration is that absorption of oral tolfenamic acid is delayed during a migraine attack, probably because of gastric stasis. Combination with metoclopramide has been studied to address this.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
6394143	1984	RCT	Cephalalgia	Tolfenamic acid, metoclopramide, caffeine and their combinations tested in migraine attacks
2375249	1990	RCT	Acta Neurol Scand	Double-blind crossover comparison of tolfenamic acid (200 or 400 mg) and paracetamol in migraine without aura
3727918	1986	RCT	Acta Neurol Scand	Tolfenamic acid and propranolol both significantly reduced attack number and duration versus placebo in prophylaxis
9563211	1998	RCT	Headache	Rapid-release tolfenamic acid had an effect comparable to sumatriptan in acute migraine (141 patients)
12474702	2002	RCT	Medicina (Kaunas)	Tolfenamic acid 300 mg compared with pizotifen for migraine prevention (192 patients)
7976233	1994	RCT	Acta Neurol Scand	Tolfenamic acid versus propranolol for prophylaxis in 76 patients; both drugs significantly effective
89390	1979	RCT	Lancet	As effective as ergotamine in reducing attack duration and intensity, with less nausea
7816790	1994	Review	Pharmacol Toxicol	Review of tolfenamic acid in acute and prophylactic migraine treatment
10234467	1999	Retrospective study	Cephalalgia	Adding tolfenamic acid to sumatriptan decreased migraine recurrence
15222892	2004	Randomised open-label	BMC Neurol	Rizatriptan alone versus combined with rofecoxib or tolfenamic acid for recurrence

India Market Information

Authorization Number	Product Name	Dosage Form	Approved Indication
34436	Clotan Capsule (Torrent Pharmaceuticals Ltd)	Strip of 10 capsules	Not stated in available data

Safety Considerations

Drug Interactions: The only recorded interaction entry is a pharmacological target association with AKR1C3 (a human enzyme), not a drug–drug interaction with a defined severity level.
Pharmacokinetic note: Migraine attacks delay oral absorption of tolfenamic acid.
Long-term tolerability: A 6-month rheumatic-disease study (600 mg/day) reported mostly mild side effects, mainly diarrhoea and other gastrointestinal disturbances, with some patients stopping treatment.

Please refer to the package insert for warnings and contraindications.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: Multiple randomised, double-blind studies show tolfenamic acid is effective in acute and prophylactic migraine treatment, with efficacy comparable to ergotamine, sumatriptan and propranolol. The mechanism is plausible. However, the evidence is largely from the 1980s–1990s, there are no registered trials, and the safety label data are missing.

To proceed, the following is needed:

Package insert warnings and contraindications for Clotan Capsule (currently a blocking gap)
The approved indication text for the Indian licence
Detailed mechanism-of-action data
Review of the older RCTs against current migraine trial standards (e.g., current endpoints and comparators)
A safety monitoring plan, particularly for gastrointestinal, renal and cardiovascular risks common to NSAIDs

Other Predicted Indications (Brief Note)

Rheumatoid arthritis also has L1-level literature support, including randomised double-blind comparisons with phenylbutazone, aspirin and ibuprofen. It would support symptomatic relief only, not disease modification, and is a candidate for separate evaluation. The other predictions (tendinitis, trigeminal autonomic cephalalgia, myositis variants, fibromyalgia, exostosis, osteoarthritis susceptibility) have no supporting evidence and remain on Hold.

Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.