Cyproterone Acetate

Evidence Level: L4

Predicted Indications: 9

Cyproterone Acetate

Pharmacist Assessment Report

Cyproterone Acetate: From Androgen-Dependent Conditions to Migraine Disorder

One-Sentence Summary

Cyproterone acetate is a synthetic antiandrogen and progestogen, used for androgen-dependent conditions such as prostate cancer, acne and hirsutism, and in some combined oral contraceptives. The TxGNN model predicts it may be effective for migraine disorder, but no clinical trials and only 3 indirect publications (all reviews or cohort studies) support this prediction, and none shows that the drug treats migraine.

Quick Overview

Item	Content
Original Indication	Not stated in the Australian registration data compiled for this report (general clinical use: androgen-dependent conditions such as prostate cancer, acne and hirsutism)
Predicted New Indication	Migraine disorder
TxGNN Prediction Score	0.9966
Evidence Level	L4
Australia Market Status	Listed on the PBS Schedule (1 of 1 items) – TGA (ARTG) registration status is not included in this data
Number of PBS Items	1 (valid: 1)
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism of action data is not available. Based on known pharmacology, cyproterone acetate is an antiandrogen with progestogenic activity. It acts on the androgen receptor and modulates sex-steroid signalling.

Migraine is hormone-sensitive, with menstrual and perimenopausal triggers. This is the only plausible link to the drug. The retrieved literature shows that progestins have differential effects on the brain, including interactions with GABA-A receptors, dopaminergic responses and opioid receptor binding. It also shows that hormone supplementation affects migraine variably in postmenopausal women. These findings are indirect, and none demonstrates that cyproterone acetate prevents or treats migraine.

The high score comes from the TxGNN model (deep learning) and may reflect similarities the model learned between related diseases, not biological evidence or clinical efficacy. One paper on long-term side effects of cyproterone acetate therapy may even point to headache as an adverse effect.

Related predictions deserve caution. The model also ranks migraine with brainstem aura and migraine susceptibility highly. The literature for these concerns hormonal contraception and vascular or thrombotic risk. Migraine with aura is a recognised risk modifier for combined hormonal contraceptives because of ischaemic stroke risk. This is a safety signal, not a therapeutic rationale.

Clinical Trial Evidence

Currently no related clinical trials registered for migraine disorder.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
14670648	2003	Review	Maturitas	Progestins interact with GABA-A receptors and other neurotransmitter systems. Cyproterone acetate increases dopaminergic responses and binds opiate receptors. No migraine outcome data.
12390622	2002	Cohort	Headache	Three oral hormone replacement regimens had differing effects on migraine in postmenopausal women. Not specific to cyproterone acetate.
10857213	2000	Review	Zentralblatt fur Gynakologie	Long-term side effects of cyproterone acetate therapy in gynaecology, including discussion of mutagenic potential. Not a migraine treatment study.

Australia Market Information

ARTG Number	Product Name	Dosage Form	Approved Indication
1269T	Cyproterone Sandoz	Tablet containing cyproterone acetate 50 mg (oral)	Not available in the data compiled for this report

Cytotoxicity

Item	Content
Cytotoxicity Classification	Hormonal (antiandrogen) therapy, not a conventional cytotoxic. Used in prostate cancer.
Myelosuppression Risk	Please refer to the Product Information (PI) warnings and precautions
Emetogenicity Classification	Please refer to the Product Information (PI) warnings and precautions
Monitoring Items	Please refer to the Product Information (PI) warnings and precautions
Handling Protection	Please refer to the Product Information (PI) warnings and precautions

Safety Considerations

Product Information warnings and contraindications were not available in the data compiled for this report. Please refer to the TGA-approved Product Information (PI) for full safety information.

Safety signals from the retrieved literature:

Thrombosis: Cyproterone acetate-containing combined oral contraceptives are associated with prothrombotic changes and a higher risk of venous thromboembolism, particularly with factor V Leiden.
Aura and stroke risk: Combined hormonal contraceptives carry ischaemic stroke and vascular risk, which is relevant in migraine with aura.
Long-term effects: Published discussion of mutagenic potential and other long-term adverse effects.
Drug interactions: The only interaction record is pharmacological, showing antagonism at the androgen receptor (AR). No clinically graded drug-drug interactions were identified.

Conclusion and Next Steps

Decision: Hold

Rationale: The migraine prediction rests on model output and indirect hormonal literature. There are no clinical trials and no evidence of benefit, and the thrombotic and vascular safety signals argue against use in migraine, especially with aura.

To proceed, the following is needed:

Mechanism of action data confirming a plausible link to migraine pathophysiology
Preclinical or early-phase clinical evidence of benefit in migraine
Review of the TGA Product Information for warnings and contraindications
A benefit-risk assessment addressing thromboembolic and stroke risk, particularly in patients with aura

Other predictions in the data (for context):

Amenorrhoea (L3) reflects an established, regulated use of cyproterone acetate with ethinylestradiol in hyperandrogenic menstrual disorders, so it is not a novel repurposing candidate. One Phase IV trial is registered (NCT01103518, 100 participants, status unknown).
Thrombophilia, factor V excess, antithrombin deficiency and heparin cofactor 2 deficiency are better read as risk flags than therapeutic opportunities.
Prinzmetal angina has no supporting evidence.
Breast fibrocystic disease has only old, small, non-randomised studies.
Disclaimer

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