title: Efficacy and tolerability of paracetamol/tramadol (325 mg/37.5 mg) combination treatment compared with tramadol (50 mg) monotherapy in patients with subacute low back pain: a multicenter, randomized, double-blind, parallel-group, 10-day treatment study.
abstract: BACKGROUND
  In various pain studies, the single-dose combination of paracetamol/tramadol (PIT) was found to be more effective than either agent alone. PIT could provide benefit in patients with subacute low back pain (LBP).
  
  
  OBJECTIVE
  This study compared the efficacy and tolerability of PIT with tramadol alone (T) in patients with subacute LBP and assessed whether, under comparable analgesic conditions, PIT would be better tolerated.
  
  
  METHODS
  This was a multicenter, randomized, double-blind, parallel-group study. Patients were enrolled if they suffered from nonspecific LBP lasting 10 to 42 days and experienced at least moderate pain (> or =40 mm on a 100-mm visual analog scale). Patients were randomized and treated for 10 days with PIT (325 mg/37.5 mg) or T (50 mg). The study outcomes were treatment efficacy (pain intensity, pain relief, patient satisfaction, physicians' assessment of pain control) and tolerability (adverse events [AEs], patients' tolerability judgment).
  
  
  RESULTS
  A total of 119 patients were enrolled (PIT, n = 59; T, n = 60). Demographic characteristics of patients were comparable between the PIT and T groups in regard to age (mean, 56.5 vs 54.1 years, respectively), sex (women/men, 38121 vs 31129), race (white, 96.1% vs 94.2%), and body mass index (24.9 vs 26.1 kg/m2). Pain intensity (mean [SD] percentage of worst imaginable pain) improved from nearly identical levels at baseline (P/T, 67.5 [13.0] vs T, 65.3 [14.6]; P = NS) to similarly low levels at the final visit (P/T, 27.9 [22.7] vs T, 24.8 [21.6]; P = NS). The reduction in pain intensity was significant in both treatment groups (P < 0.001). Adequate pain relief (ie, "moderate," "important," or "complete") was observed in 81.6% (40149) of PIT patients versus 82.9% (39147) of T patients (P = NS). Comparably high rates of overall patient satisfaction (72.5% [37151] vs 72.9% [35148], respectively; P = NS) were achieved. Both treatment groups took a comparable number of daily units of study medication, which resulted in significantly (P < 0.001) lower daily doses of tramadol in the P/T group (mean [SD], 172.5 [46.6] mg) than in the T group (227.3 [59.7] mg). More P/T patients (84.3%) than T patients (68.8%) judged treatment tolerability as good or very good (P = NS). Significantly fewer AEs (P < 0.001) were observed in PIT patients, and the overall incidence of AEs (mostly opioid-typical AEs [eg, nausea, dizziness/vertigo, sleepiness/drowsiness, constipation, vomiting]) was much lower after P/T compared with T (P = 0.019). The most common AEs in the P/T and T groups were nausea (8159 vs 21160 patients, respectively; P = 0.012) and dizziness (3/59 vs 15/60 patients; P= 0.006).
  
  
  CONCLUSIONS
  Tramadol, alone and in combination with paracetamol, provided highly effective analgesia for these patients with subacute LSP However, the combination of PIT, which resulted in 25% less tramadol than equianalgesic daily doses of T alone, considerably reduced the incidence of AEs and improved tolerability.
authors.affiliation: Service de Medicine Interne et Consultation de la Douleur, Hôpital Dieu, Paris, France. serge.perrot@htd.aphp.fr
authors.forename: Serge
authors.initials: S
authors.lastname: Perrot
authors.forename: Dirk
authors.initials: D
authors.lastname: Krause
authors.forename: Philippe
authors.initials: P
authors.lastname: Crozes
authors.forename: Claude
authors.initials: C
authors.lastname: Naïm
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D006801:Humans; D017116:Low Back Pain / Q000188:drug therapy*; D014147:Tramadol / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000082:Acetaminophen; D014147:Tramadol