Tramadol sustained-release capsules.

Tramadol is a synthetic, centrally acting analgesic. A sustained-release (SR) capsule formulation of tramadol gradually releases active drug, allowing for twice-daily dosing. Compared with tramadol SR tablets, tramadol SR capsules produced a smoother plasma concentration profile, with more gradual absorption and lower peak concentrations. There was less intra- and intersubject variability in tramadol plasma concentrations with SR capsules versus SR. Tramadol SR capsules had identical bioavailability to tramadol immediate-release (IR) capsules with lower peak concentrations and less fluctuation in plasma concentrations. Tramadol SR 100 mg capsules administered twice daily had equivalent efficacy to tramadol IR 50 mg capsules administered four times daily in the treatment of moderate to severe chronic low back pain in a well designed study. Patients receiving tramadol SR capsules were significantly less likely than those receiving tramadol IR capsules to report nausea. Starting treatment with tramadol SR capsules at a dosage of 50 mg twice daily with subsequent dose escalation resulted in improved tolerability in patients with moderate to severe chronic pain. The lowest tramadol SR capsule dosage of 50 mg twice daily (administered to 35% of patients with moderate to severe non-oncological pain) significantly improved pain intensity and frequency in 83.4% and 70.4% of patients, respectively, in a postmarketing observational study evaluating tramadol SR capsules 50-200 mg twice daily (n = 3888).