Isobolographic analysis of the dual-site synergism in the antinociceptive response of tramadol in the formalin test in rats.

Tramadol is an atypical opioid with a complex mechanism of action including a synergistic interaction between the parent drug and an active metabolite. The local action of the parent drug is poorly documented. This study was designed to evaluate the site-site interaction of the antinociception produced by tramadol given by two different routes.

Analgesic efficacy of tramadol by route of administration in a clinical model of pain.

The objective of this study was to evaluate the analgesic efficacy produced by tramadol given by two different routes of administration in patients experiencing pain after removal of an impacted mandibular third molar under local anesthesia. A double-blind, randomized, placebo-controlled clinical trial was conducted. Patients were assigned into four groups of treatment, twelve subjects per group: Group A, tramadol 50 mg IM one hr before surgery; group B, tramadol 50 mg into the surgical site; group C, tramadol by both routes of administration, 50 mg IM one hr before surgery plus 50 mg into the surgical site; and group D, control.

Evidence of self-synergism in the antinociceptive effect of tramadol in rats.

Tramadol is an atypical opioid with a complex mechanism of action including the synergistic interaction between the parent drug and an active metabolite. However, the local action of the parent drug is poorly documented. This study was designed to evaluate the site-site interaction of the antinociception produced by tramadol given by two different routes.