Assessment of tramadol as an alternative opioid instead of codeine at the second step of the WHO analgesic scale

OBJECTIVES: To assess the clinical equivalence of tramadol and codeine (reference drugs at the second step of the WHO analgesic scale) in terms of effectiveness, safeness and patient preference. MATERIALS AND METHODS: Double-blind randomized cross-sectional study. Sixty patients with oncologic pain were included. Codeine (Co) and tramadol (Tra) were administered in equivalent doses (individually titrated). Analgesic effectiveness was measured using a VAS and safeness was assessed according to the incidence of nausea, vomiting, sleep disorders, constipation and mood changes. Finally, patient preference for one of the two drugs was determined. Wilcoxon and Chi-square tests were conducted for non-parametric data, as well as the t-test for parametric data. RESULTS: A total of 44 patients (23 sequence Tra-Co and 21 sequence Co-Tra) were analyzed. Baseline characteristics of both groups were similar. The initial severity of pain (VA S ) was 6.2 ± 2.6 in the Tra-Co group and 6.6 ± 2.5 in the Co - Tra group. The average maximum doses used were 68.25 ± 24.2 mg for tramadol and 48.8 ± 15.5 mg for codeine each 6 hours. Both drugs were equally effective for the management of pain in the two periods; first Tra 4.1 ± 2.5 and Co 3.4 ± 2.2; second Tra 2.3 ± 2.9 and Co 2.3 ± 1.8. Incidence of side effects and use of laxatives and antiemetics were not significantly different in both groups . Patient preference was equal for both drugs. CONCLUSIONS: Tramadol and codeine are equally effective for the management of oncologic pain, as well as similar in their side effects and patient preference. This findings support the clinical equivalence of both drugs at the second step of the WHO scale for the management of cancer pain