Two doses of oral sustained-release tramadol do not reduce pain or morphine consumption after modified radical mastectomy: a randomized, double blind, placebo-controlled trial.J Med Assoc Thai. 2004 Jan; 87(1):24-32.JM
Tramadol is a weak opioid agonist with antinociceptive effects through its action on the mu-receptor and by inhibiting the neuronal re-uptake of both noradrenaline and serotonin. Tramadol is commonly used for treatment of mild to moderate post-operative pain. An oral form of sustained-release tramadol (SR) was recently formulated for reducing the administration frequency from qid to bid.
To evaluate the analgesic efficacy and safety of two doses of oral tramadol SR for the treatment of pain after modified radical mastectomy.
Randomized, double blind, placebo-controlled trial.
Fifty women were randomly allocated to receive either tramadol SR 100 mg (group T), or placebo tablet (group P) orally approximately 1 hour before surgery with a repeat dose administered 12 hours later by nurses not apprised of the patient groupings. All patients received the standard general anesthesia. Post-operatively, nurses in the research team assessed pain using a visual analog scale 0-100 mm at rest (rVAS) and during arm movements (mVAS) at admission to postanesthesia care unit (PACU) (T0) and 2 (T2), 6 (T6), 12 (T12) and 24 (T24) hours after surgery. Rescue analgesia was provided for 24 hours via a morphine-loaded patient-controlled analgesia (PCA) device at 1 mg bolus with a 5-minute lockout interval. Cumulative morphine consumption and adverse events were recorded.
Twenty-five patients with comparable baseline characteristics from each group were studied. The proportions of patients with VAS > 30 (both rVAS and mVAS) at each measurement period were not significantly different between the groups except for the mVAS at T24, where the proportion in group T was higher than group P (48% vs 20%, 95% CI of difference: -53%, -3%, p = 0.04). The median morphine consumption in both groups at T2, T6, T12 and T24 were comparable. No serious adverse effects were observed; however, patients in group T reported nausea and vomiting more than group P (56% vs 24%, p = 0.02).
Two doses of oral tramadol SR 100 mg had no effect on post-operative pain scores and morphine consumption in patients who underwent modified radical mastectomy. In fact, more patients in the tramadol group reported nausea and vomiting than the placebo group.