Tramadol and Metabolite, Urine
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Tramadol, a centrally-acting opioid analgesic, is utilized in the treatment of moderate to moderately severe pain. Tramadol acts as an opiate agonist through the binding of the parent drug and its O-desmethyl (M1) metabolite to mu-opioid receptors and through the weak inhibition of norepinephrine and serotonin reuptake. The active metabolite, O-desmethyltramadol, is a considerably more potent mu-opioid receptor agonist than its parent drug. In urine, approximately 30% of tramadol is excreted as unchanged drug while approximately 60% is excreted as metabolites (N- and O-desmethyltramadol). The half-life of tramadol and O-desmethyltramadol is approximately 7 hours.
Monitoring of compliance utilizing tramadol
Detection and confirmation of the illicit use of tramadol
The presence of tramadol or O-desmethyltramadol >50 ng/mL is a strong indicator that the patient has used tramadol.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Urine concentrations do not correlate well with serum drug levels and are not intended for therapeutic drug management.
Results are intended to be interpreted by a physician or health care professional. This test is not intended for use in employment-related testing.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Cutoff: <50 ng/mL
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Grond S, Sablotzki: Clinical pharmacology of tramadol. Clin Pharmacokinet 2004;43(13):879-923
2. Dayer P, Collart L, Desmeules J: The pharmacology of tramadol. Drugs 1994;47 Suppl 1:3-7