The Role of Papaverine in the Molecular and Biomechanical Mechanisms of Cervical Ripening: A Narrative Review.

Papaverine (PPV) has long been used in obstetric practice to facilitate cervical dilatation, yet its mechanism of action remains poorly understood. This creates an apparent paradox, as experimental studies indicate that PPV suppresses several inflammatory signaling pathways traditionally considered essential for physiological cervical ripening, despite its reported clinical benefits during labor. In this narrative review, we critically integrate current knowledge of cervical ripening biology with the pharmacological actions of PPV to reconcile this discrepancy. We propose that the reported clinical effects of PPV may be explained predominantly by modulation of cervical biomechanics rather than by direct enhancement of inflammatory remodeling. In particular, smooth muscle relaxation and cyclic nucleotide-dependent signaling may reduce functional cervical resistance and facilitate cervical dilatation despite the predominantly anti-inflammatory molecular profile of PPV. Although this mechanistic framework remains hypothetical, it provides a biologically plausible explanation for the apparent discrepancy between the molecular and clinical effects of papaverine and highlights priorities for future experimental and clinical research.