Efficacy and Tolerability of Pridinol Mesylate Versus Quinine Sulfate in the Treatment of Nocturnal Leg Cramps: A Propensity Score-Matched Real-World Analysis of Depersonalized 4-Week Data from the German Pain e-Registry (PRISCILA Study).

Background: Nocturnal leg cramps (NLCs) are common, especially in older adults, and may cause substantial distress, sleep disturbance, and functional impairment. Despite widespread clinical use of quinine sulfate (QUI), safety concerns limit its use. Pridinol mesylate (PRI), a centrally acting antispasmodic, may offer a promising alternative in clinical practice. Objective: To evaluate the clinical effectiveness and tolerability of PRI versus QUI in patients with NLCs. Methods: We conducted a retrospective, non-interventional, propensity score-matched analysis of anonymized routine data from 1722 adult patients (861 per group) with NLCs from the German Pain e-Registry (GPeR). Patients initiating either PRI or QUI between 2018 and 2023 were included. The primary outcome was a predefined composite responder rate (≥50% reduction in NLC frequency, duration, and affected nights, with no treatment discontinuation due to adverse drug reactions [ADRs] or inefficacy). Secondary outcomes included pain intensity, quality-of-life, disability, and ADR frequency. Results: PRI treatment resulted in a significantly higher responder rate (56.9%) compared to QUI (48.4%, p < 0.001; NNT = 12) due to greater short-term reductions in NLC episodes, duration, and pain intensity. The overall ADR rates were numerically higher with PRI (8.6%) than with QUI (6.7%), but discontinuation rates due to ADRs or inefficacy were comparable between groups and occurred in 3.1/2.6% with PRI/QUI (p = 0.865). Conclusions: In this large, real-world, propensity score-matched analysis, pridinol treatment was associated with a modest short-term advantage over quinine in several efficacy outcomes, while overall tolerability appeared broadly comparable. Given the retrospective, non-interventional design and the limited 4-week observation period, these findings should be interpreted as hypothesis-generating rather than confirmatory.