Papaverine
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Papaverine: From Peripheral Vascular Disease to Ischemic Disease
One-Sentence Summary
Papaverine is a smooth muscle relaxant and vasodilator, originally used for peripheral vascular disease, intermittent claudication, peripheral arterial disease, brain ischemia and transient ischemic attack. The TxGNN model predicts it may be effective for ischemic disease, but the supporting evidence is thin: 1 registered clinical trial (an observational registry that does not test papaverine as a treatment) and 20 publications, mostly reviews, procedural reports and case studies.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Peripheral vascular disease, intermittent claudication, peripheral arterial disease, brain ischemia, transient ischemic attack (from the knowledge graph; no approved indication text is available for the New Zealand licence) |
| Predicted New Indication | Ischemic disease |
| TxGNN Prediction Score | 99.91% |
| Evidence Level | L4 |
| New Zealand Market Status | Cancelled only (no currently valid authorization) |
| Number of Authorizations | 1 (cancelled) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data from DrugBank is not available for this report. Pharmacology data compiled for this report show that papaverine inhibits phosphodiesterases (PDE3A, PDE3B and PDE10A), which raises cAMP/cGMP in vascular smooth muscle and causes vasodilation. Clinically, it has been used as an antispasmodic in the gastrointestinal tract and as a vasodilator of cerebral, coronary and penile blood vessels.
The predicted indication is consistent with the original ones. Peripheral arterial disease, brain ischemia and transient ischemic attack are all conditions of insufficient blood supply, and a drug that relaxes vascular smooth muscle could plausibly improve perfusion. The literature shows supportive uses such as intra-arterial infusion in non-occlusive mesenteric ischemia, spinal cord protection during aortic surgery, and intracoronary use to measure coronary flow reserve. An animal study also reports a reduced infarct volume after cerebral ischemia.
However, these are mostly procedural or diagnostic uses, not randomized trial evidence that papaverine treats ischemic disease. "Ischemic disease" is also a very broad category, so the prediction is best treated as a research question rather than a confirmed new use.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT06125392 | N/A | Recruiting | 1000 | MICRO-SNAPE registry of patients with chronic angina and no obstructive coronary stenosis, collecting data on microvascular dysfunction and coronary spasm. It is diagnostic and observational and does not test papaverine as a treatment. |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 23076900 | 2012 | Systematic review | Cochrane Database Syst Rev | Cerebrospinal fluid drainage to reduce spinal cord ischemia during aortic aneurysm surgery (papaverine is not the main intervention) |
| 14974026 | 2004 | Systematic review | Cochrane Database Syst Rev | Earlier version of the review above |
| 3661361 | 1987 | Diagnostic clinical study | Am Heart J | Intracoronary papaverine was superior to radiographic contrast for measuring coronary flow reserve in ischemic heart disease |
| 21761272 | 2011 | Guideline | Neurocritical Care | Critical care guidelines on endovascular management of cerebral vasospasm after subarachnoid hemorrhage |
| 7590571 | 1995 | Review | Hepato-gastroenterology | Non-occlusive mesenteric ischemia, a condition in which vasodilator infusion is used |
| 32713799 | 2020 | Preclinical (mouse) | J Pharmacol Sci | Papaverine reduced ischemic infarct volume in focal cerebral ischemia, with anti-inflammatory and immunomodulatory effects |
| 28455799 | 2018 | Case report | J Robot Surg | Periarterial papaverine treated renal artery vasospasm during robot-assisted partial nephrectomy |
| 16368347 | 2006 | Comparative study | Ann Thorac Surg | Papaverine versus a glyceryl trinitrate/verapamil solution for internal thoracic artery spasm |
| 28832798 | 2017 | Preclinical (rat) | Braz J Cardiovasc Surg | Papaverine and ascorbic acid against liver ischemia-reperfusion injury after aortic cross-clamping |
| 1291208 | 1992 | Clinical study (indirect) | Chin Med J | Ligusticum chuanxiong preparations in ischemic stroke were as good as or better than controls including papaverine |
New Zealand Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| 333328 (cancelled) | Hospira | Injection 12 mg per ml, 10 ml ampoule | Not available |
Safety Considerations
- Contraindication-related conditions (from the drug-disease knowledge graph, not label text): liver disease, gallbladder disease, hypotensive disorder, coronary artery disease, myocardial infarction, coronary thrombosis, hemoglobinopathy, sudden cardiac arrest, heart conduction disease, glaucoma, atrioventricular block. Several of these (coronary artery disease, myocardial infarction, heart conduction disease) overlap with the cardiovascular population most relevant to ischemic disease, so they need careful review.
- Pharmacological targets: papaverine inhibits PDE3A, PDE3B and PDE10A. No drug-drug interaction severity levels are available.
- Literature signals: a 1975 report describes antagonism of levodopa by papaverine, and papaverine injection into the penis is associated with ischemic priapism.
Please refer to the package insert for full warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: The TxGNN score is very high (99.91%), and the vasodilator mechanism is plausible. However, there is no randomized evidence for treating ischemic disease, the only registered trial is an observational diagnostic registry, and the product's New Zealand licence has been cancelled. The knowledge graph also lists coronary artery disease and myocardial infarction as contraindication-related conditions. The idea is a research question, not a ready-to-use new indication.
To proceed, the following is needed:
- The Medsafe package insert, to confirm warnings and contraindications (a blocking gap for safety screening)
- Mechanism-of-action data from DrugBank
- A narrower, clinically defined target (for example, a specific vasospasm or perfusion setting) in place of the broad "ischemic disease" category
- Controlled clinical evidence of efficacy in that target condition
- A route and formulation plan, since the only New Zealand licence was for an injection and has been cancelled
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.