title: [Oral N-acetylcysteine in the treatment of Raynaud's phenomenon secondary to systemic sclerosis: a randomized, double-blind, placebo-controlled clinical trial].
abstract: OBJECTIVE
  To evaluate the safety and efficacy of N-acetylcysteine (NAC) orally on digital microcirculation blood flow in patients with Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc).
  
  
  METHODS
  This was a randomized, double-blind, placebo-controlled trial in which 42 patients with SSc received oral NAC at a dose of 600mg tid (21 patients, mean age 45.6±9.5 years) or placebo (21 patients, mean age 45.0±12.7 years) for four weeks. The primary endpoint was the change in cutaneous microcirculation blood flow before and after cold stimulation measured by laser Doppler imaging (LDI) at weeks 0 and 4. The frequency and severity of RP and the number of digital ulcers were also measured at weeks 0 and 4. The adverse events were recorded in the fourth week.
  
  
  RESULTS
  There was no significant change in digital blood flow assessed by LDI before or after cold stimulus after four weeks of NAC or placebo. Both groups showed significant improvement in the frequency and severity of RP attacks, with no difference between the two groups. At the end of the study, the placebo group had three digital ulcers, while the NAC group showed no ulcers. NAC was well tolerated and no patient discontinued the treatment.
  
  
  CONCLUSIONS
  NAC orally at a dose of 1800mg/day showed no vasodilator effect on hands' microcirculation after four weeks of treatment in patients with RP secondary to SSc.
authors.affiliation: Disciplina de Reumatologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: Marcelo José Uchoa
authors.initials: MJ
authors.lastname: Correa
authors.affiliation: Disciplina de Reumatologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: Henrique Ataíde
authors.initials: HA
authors.lastname: Mariz
authors.affiliation: Disciplina de Reumatologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: Luís Eduardo Coelho
authors.initials: LE
authors.lastname: Andrade
authors.affiliation: Disciplina de Reumatologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil. Electronic address: criskayser@terra.com.br.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Kayser
mesh_terms: D000111:Acetylcysteine / Q000008:administration & dosage*; D000284:Administration, Oral; D004311:Double-Blind Method; D005260:Female; D016166:Free Radical Scavengers / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D011928:Raynaud Disease / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D012039:Regional Blood Flow; D012595:Scleroderma, Systemic / Q000150:complications
chemical_list: D016166:Free Radical Scavengers; D000111:Acetylcysteine
keywords: Esclerose sistêmica; Estresse oxidativo; Fenômeno de Raynaud; N‐acetilcisteína; N‐acetylcysteine; Oxidative stress; Raynaud's Phenomenon; Systemic sclerosis; Tratamento; Treatment