Background:Aminaphtone (AMI) is a bioflavonoid compound, classically used for “capillary disorders”.In vitroAMI interferes with adhesion molecules (sELAM-1 and sVCAM-1) and with vascular endothelial cadherin degradation thus defending vessels permeability. Moreover, it counteracts vasoconstriction, downregulating endothelin-1 production at a gene level (1-3).In vivoAMI ameliorates clinical symptoms of several clinical conditions, above all Raynaud’s phenomenon (RP), either primary or secondary to systemic sclerosis (SSc), as demonstrated by a recent six-month study (4).Objectives:To evaluate long-term tolerability of standard dosage of AMI in a real-life cohort of SSc patients with secondary RP.Methods:Seventy-eight SSc patients (mean age 65±13 years; mean disease duration 9±7 years) treated with AMI due to active RP were enrolled (ACR/EULAR 2013 criteria). They were taking various concomitant treatments, including aspirin, calcium-channel blockers, cyclic intravenous iloprost, immunomodulators, endothelin receptor antagonists. SSc patients performed periodic clinical assessments and blood tests on average every four months per clinical practice. Duration of AMI administration, side effects, and self-assessment of Raynaud Condition Score (RCS) in a scale from 0 (absence of pain) to 10 (intolerable pain) were retrospectively taken into account.Results:Duration of AMI administration was between six and sixty-seven months (mean 31±20 months). AMI was administered at 75 mgbis in diedosage, as standard initial posology. At baseline, mean RCS was 7.3±0.8. After 3 months of treatment sixty-four patients (82%) yet referred a subjective improvement of RCS (3.5±0.8, p=0.03), whereas 14 patients (18%) were clinically unsatisfied (RCS 6.1±0.4, p=1.12). In this last group, posology was increased to 75 mgtris in die, with a satisfactory amelioration in further nine patients (93,6%) (RCS 4.0±0.6 p=0.04), while five patients (6,4%) definitively discontinued therapy for subjective ineffectiveness within six months. Patients referred a sustained improvement of RCS along the observational period (31±20 months) (last RCS 3.7±0.7, p=0.03 vs baseline). During the follow-up, five patients (6,4%) referred headache as side effect: three of them had to reduce AMI posology to 75 mg per day, while maintaining clinical benefits. Periodic blood tests did not reveal any significant alteration attributable to AMI. No other side effects related to the drug appeared during the treatment period.Conclusion:AMI shows an acceptable medium-long-term tolerability along with sustained efficacy in the management of SSc-related RP, without disabling side effects. However, the retrospective design, the absence of a placebo-control group and the concomitant standard therapy limit the results, and a randomized controlled trial for AMI use in the management of SSc-related RP is desirable.References:[1]Scorza R et al. 2008.Clin Ther30(5):924-9.[2]Felice F et al. 2018.Phlebology33(9):592-599.[3]Scorza R et al. 2008.Drugs R D9(4):251-7.[4]Ruaro B et al. 2019.Front Pharmacol10:293.Disclosure of Interests:Emanuele Gotelli: None declared, Sabrina Paolino: None declared, Federica Goegan: None declared, Francesco Cattelan: None declared, Massimo Patanè: None declared, Carmen Pizzorni: None declared, Maurizio Cutolo Grant/research support from: Bristol-Myers Squibb, Actelion, Celgene, Consultant of: Bristol-Myers Squibb, Speakers bureau: Sigma-Alpha, Alberto Sulli Grant/research support from: Laboratori Baldacci