Acute pain and side effects after tramadol in breast cancer patients: results of a prospective double-blind randomized study

The objective of this study was to evaluate the severity of acute pain and side effects in breast cancer patients postoperatively treated with two regimens of tramadol with paracetamol in a prospective double-blind study. Altogether 117 breast cancer patients who had axillary lymphadenectomy were randomized into two analgesic study groups and the analgesic treatment lasted 4 weeks. Stronger analgesia group received every 8 h 75/650 mg of tramadol with paracetamol, while weaker analgesia group received every 8 h 37.5/325 mg of tramadol with paracetamol. Patients with the higher dose of tramadol had less pain during the 1st and 4th week than patients with the lower dose. Frequency of nausea, vomiting, lymphedema or range of shoulder movement was not significantly different between the two groups of patients. Constipation was significantly more common in the group with stronger analgesia during the 2nd week in comparison to patients with weaker analgesia. The patients who were on 75/650 mg of tramadol with paracetamol had less pain in comparison to patients who were on 37.5/325 mg. Side effects were mild, but common in both groups of patients.

Assessment of tramadol pharmacokinetics in correlation with CYP2D6 and clinical symptoms

Objectives Due to lack of adequate data on tramadol kinetic in relevance of CYP2D6 toxicity, this study was designed to investigate the effect of CYP2D6 phenotype in tramadol poisoning. The saliva, urine and blood samples were taken at the admission time. Consequently, concentration of tramadol and its major metabolites were measured. Methods A pharmacokinetic and metabolic study was developed in cases of tramadol poisoned (n=96). Cases of tramadol poisoned evidenced seizure, hypertension, dizziness, nausea and vomiting symptoms participated. Results Female cases showed higher N-desmethyltramadol (M2) tramadol concentrations than male cases: in urine (40.12 ± 124.53 vs. 7.3 ± 7.13), saliva (16.91 ± 26.03 vs. 5.89 ± 7.02), and blood (1.11 ± 1.56 vs. 0.3 ± 0.38) samples. Significant correlation between blood, saliva, and urine concentrations were found (r = 0.5). Based on the metabolic ratio of O-desmethyltramadol (M1) of male (0.53 ± 0.22) and female (0.43 ± 0.26), poisoning and severe symptoms like seizure in female occurs statistically fewer (13.04%) than in male (50.6%). Assessment of CYP2D6 phenotype showed all of the participants were extensive metabolizers (EM) and their phenotype was associated with clinical symptoms. Conclusions According to our results, M1 as a high potent metabolite has an important role in toxicity and the likelihood of poisoning in people with EM phenotype. Finally, tramadol metabolic ratio may justify the cause of various symptoms in human tramadol poisoning.

Assessment of tramadol pharmacokinetics in correlation with CYP2D6 and clinical symptoms

Objectives Due to lack of adequate data on tramadol kinetic in relevance of CYP2D6 toxicity, this study was designed to investigate the effect of CYP2D6 phenotype in tramadol poisoning. The saliva, urine and blood samples were taken at the admission time. Consequently, concentration of tramadol and its major metabolites were measured. Methods A pharmacokinetic and metabolic study was developed in cases of tramadol poisoned (n=96). Cases of tramadol poisoned evidenced seizure, hypertension, dizziness, nausea and vomiting symptoms participated. Results Female cases showed higher N-desmethyltramadol (M2) tramadol concentrations than male cases: in urine (40.12 ± 124.53 vs. 7.3 ± 7.13), saliva (16.91 ± 26.03 vs. 5.89 ± 7.02), and blood (1.11 ± 1.56 vs. 0.3 ± 0.38) samples. Significant correlation between blood, saliva, and urine concentrations were found (r = 0.5). Based on the metabolic ratio of O-desmethyltramadol (M1) of male (0.53 ± 0.22) and female (0.43 ± 0.26), poisoning and severe symptoms like seizure in female occurs statistically fewer (13.04%) than in male (50.6%). Assessment of CYP2D6 phenotype showed all of the participants were extensive metabolizers (EM) and their phenotype was associated with clinical symptoms. Conclusions According to our results, M1 as a high potent metabolite has an important role in toxicity and the likelihood of poisoning in people with EM phenotype. Finally, tramadol metabolic ratio may justify the cause of various symptoms in human tramadol poisoning.