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

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 (≥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.