Isoflurane

證據等級: L5

預測適應症: 7 個

Isoflurane: From General Anesthesia to Prinzmetal Angina, Migraine, and Other Predicted Indications

One-Sentence Summary

Isoflurane (DrugBank DB00753) is a volatile halogenated-ether agent whose established use is inhalational general anesthesia; detailed original-indication and mechanism-of-action records are not available in this evidence pack, and it currently holds no marketing license in Taiwan. The TxGNN model surfaced 7 candidate new indications, ranked highest for Prinzmetal angina (99.67%), but literature support is uneven: only migraine disorder (13 publications) and manic bipolar affective disorder (3 publications) have any supporting evidence, while the remaining 5 candidates — including the top-ranked Prinzmetal angina — rest on the model score alone, with zero clinical trials identified for any candidate.

Quick Overview

Item	Content
Original Indication	Not available in regulatory data (isoflurane is generally used for induction/maintenance of general anesthesia)
Predicted New Indication (top rank)	Prinzmetal angina
TxGNN Prediction Score	99.67%
Evidence Level	L5 (model prediction only, no supporting trials or literature)
Taiwan Market Status	Not marketed
Number of Taiwan Licenses	0
Recommended Decision	Hold

All Predicted Indications at a Glance

Rank	Disease	TxGNN Score	Evidence Level	Decision Stage	Recommendation
1	Prinzmetal angina	99.67%	L5	S0	Hold
2	Tourette syndrome	99.61%	L5	S0	Hold
3	Manic bipolar affective disorder	99.57%	L3	S1	Research Question
4	Trichotillomania	99.54%	L5	S0	Hold
5	Dysthymic disorder	99.27%	L5	S0	Hold
6	Nephrogenic syndrome of inappropriate antidiuresis	99.09%	L5	S0	Hold
7	Migraine disorder	99.06%	L4	S1	Research Question

Why is This Prediction Reasonable?

Currently, detailed mechanism-of-action data for isoflurane is flagged as a data gap in this evidence pack. Based on general pharmacological knowledge, isoflurane is a volatile general anesthetic that potentiates GABA-A receptor activity and antagonizes NMDA receptors, producing dose-dependent central nervous system depression, including a distinctive “burst-suppression” EEG pattern at high concentrations. No original indication text or Taiwan regulatory record was found for this drug, so the mechanistic link below is drawn entirely from the two indications with any evidentiary support.

For migraine disorder (L4), the strongest mechanistic thread is isoflurane’s demonstrated suppression of cortical spreading depression (CSD) in preclinical models — CSD is the electrophysiological correlate of migraine aura. This is reinforced by case-report evidence of general anesthesia (including isoflurane) being used to terminate refractory status migrainosus, though no controlled trials confirm this translational path.

For manic bipolar affective disorder (L3), the rationale rests on isoflurane’s ability to induce burst-suppression cortical activity, a state mechanistically analogous to the cortical inhibition produced by electroconvulsive therapy (ECT). One small cohort study found isoflurane-induced burst-suppression comparable to ECT in treatment-refractory depression, but direct evidence for the manic (rather than depressive) pole of bipolar disorder is weak. The remaining five candidates (Prinzmetal angina, Tourette syndrome, trichotillomania, dysthymic disorder, nephrogenic SIAD) have no clinical trials or literature identified — their mechanistic rationale, where offered, is speculative and score-driven only.

Clinical Trial Evidence

Currently no related clinical trials registered for any of the 7 predicted indications (ClinicalTrials.gov and ICTRP searches both returned zero results across all indications).

Literature Evidence

Migraine Disorder (L4)

PMID	Year	Type	Journal	Key Findings
8665587	1996	Review	Cephalalgia	Inhalational anesthetics, including isoflurane, inhibit cortical spreading depression — proposed relevance to migraine pathophysiology
26323741	2015	Cohort	Brazilian Journal of Anesthesiology	Case report: status migrainosus treated with general anesthesia; propofol and isoflurane act on sub-GABA-A receptors, theoretically useful for severe migraine
26363696	2015	Cohort	Revista Brasileira de Anestesiologia	Portuguese-language version of the same status migrainosus case report above
17267580	2007	Review	J Pharmacol Exp Ther	NMDA receptor antagonists suppress cortical spreading depression in rats — therapeutic potential for migraine
27122032	2016	Review	J Neuroscience	Sensory cortex susceptibility to spreading depolarizations, the biological substrate of migraine aura
22523186	2012	Review	Cephalalgia	Chronic topiramate suppresses potassium-induced cortical spreading depression in rats
39354357	2024	Review	J Headache Pain	Passive smoking effects on cortical spreading depolarization susceptibility in a mouse model
40764901	2025	RCT	J Headache Pain	CGRP antagonist atogepant does not affect cortical spreading depression susceptibility in rats

Note: 5 additional lower-relevance publications on trigeminal/CGRP mechanisms were identified but omitted here as they do not reference isoflurane or spreading-depression suppression directly.

Manic Bipolar Affective Disorder (L3)

PMID	Year	Type	Journal	Key Findings
8462536	1993	Cohort	European Journal of Anaesthesiology	Burst-suppression isoflurane anesthesia compared to ECT in 12 patients with severe treatment-refractory depression; marked improvement in both arms
7502646	1995	Review	AANA Journal	Case report of isoflurane anesthesia in a patient with manic-depressive psychosis; malignant hyperthermia differential diagnosis discussion
18930636	2008	Review	Psychiatry Research	Animal model of mania using isoflurane-anesthetized rats with PET imaging of frontal glucose metabolism

Other Candidates (Prinzmetal angina, Tourette syndrome, trichotillomania, dysthymic disorder, nephrogenic SIAD)

Currently no related literature available for these indications.

Safety Considerations

Please refer to the package insert for safety information.

Conclusion and Next Steps

Decision: Hold

Rationale: The highest-scoring TxGNN candidate (Prinzmetal angina) has no supporting clinical or literature evidence (L5), and isoflurane is not currently marketed in Taiwan, so no regulatory or safety baseline exists to build on. Two lower-ranked candidates — migraine disorder (L4) and manic bipolar affective disorder (L3) — have preclinical/mechanistic and case-report support and are appropriately flagged as Research Questions (S1) rather than ready for clinical evaluation.

To proceed, the following is needed:

TFDA label warnings/contraindications (currently blocking — flagged as DG001)
Confirmed mechanism-of-action data from DrugBank (flagged as DG002)
Original indication and regulatory history, since isoflurane has no Taiwan license on record
For migraine and bipolar mania candidates specifically: controlled studies (not just case reports/animal models) testing isoflurane or burst-suppression anesthesia against these indications before any Go/Guardrails decision
Route-of-administration feasibility assessment — isoflurane is an inhalational anesthetic, which constrains its practical use for non-procedural chronic indications like dysthymic disorder or trichotillomania
Disclaimer

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