New Approaches in Oncology for Repositioning Drugs: The Case of PDE5 Inhibitor Sildenafil.
Level 5 - mechanism / opinion, no new human data
Narrative review of molecular mechanisms and drug repurposing concepts without systematic review methodology or new human data
PubMed 33718200 · doi:10.3389/fonc.2021.627229
What was done
This narrative review synthesized the molecular mechanisms of phosphodiesterase-5 (PDE5) inhibitors—specifically sildenafil, tadalafil, and vardenafil—focusing on nitric oxide and cyclic guanosine monophosphate (cGMP) signaling, and evaluated their theoretical potential for drug repurposing in oncology.
What was found
The abstract reports no quantitative findings, clinical trial metrics, or numerical data. It provides a qualitative and mechanistic overview proposing that the pleiotropic molecular actions of PDE5 inhibitors in cGMP signaling could be leveraged against cancer.
Why it matters
Repurposing already-approved agents like sildenafil could substantially reduce the cost and timeline of oncology drug development if preclinical mechanistic insights translate to clinical efficacy.
Limits
The paper is a narrative overview without systematic search criteria, meta-analysis, or novel empirical data. Clinical efficacy, optimal dosing, adverse effects, and oncologic outcomes in human populations are not quantified in the abstract.
Cited by
- supports PDE5 inhibitor erectile dysfunction drugs were originally developed and clinically trialed as a treatment for angina.