Formoterol Concentrations in Blood and Urine

Abstract

We found no significant differences in urinary and serum concentrations of formoterol between asthmatic and healthy subjects. We found high interindividual variability in the concentrations in all groups. Our data support the WADA 2012 urinary threshold of 30 ng·mL(-1) formoterol as being an adverse analytical finding.

Evaluation of the urinary threshold concentration of formoterol in sports drug testing

“…The maximum excretion rate was obtained for all volunteers from 1–2 h after administration of the compound (12.3 ± 1.8 µg/min). Results of concentrations after inhaled administration agree with previously published data . After single inhaled doses of 18 µg of formoterol, concentrations in the range of 0.5–17 ng.mL ‐1, up to 11.4 ng.mL ‐1 and up to 15.9 ng.mL ‐1 were obtained in previous studies.…”

“…Results of concentrations after inhaled administration agree with previously published data . After single inhaled doses of 18 µg of formoterol, concentrations in the range of 0.5–17 ng.mL ‐1, up to 11.4 ng.mL ‐1 and up to 15.9 ng.mL ‐1 were obtained in previous studies. After repeated inhaled doses, concentrations up to 15 ng.mL ‐1 and 25.6 ng.mL ‐1 were described.…”

“…After single inhaled doses of 18 µg of formoterol, concentrations in the range of 0.5–17 ng.mL ‐1, up to 11.4 ng.mL ‐1 and up to 15.9 ng.mL ‐1 were obtained in previous studies. After repeated inhaled doses, concentrations up to 15 ng.mL ‐1 and 25.6 ng.mL ‐1 were described. The cumulative percentage of the dose recovered in urine up to 24 h ranged from 10.7 to 17.9% (mean 14.7%), in agreement with data of previous studies …”

“…In summary, administration by inhalation of the maximum dose of formoterol allowed by WADA following the recommended therapeutic regime should not produce false positive results using the threshold concentration of 30 ng.mL ‐1 . In a recent study, administrations every 2 h of 18 µg of inhaled formoterol resulted in concentrations in urine up to 21.4 ng.mL ‐1 after the second dose (total dose, 36 µg) and up to 25.6 ng.mL ‐1 after the fourth dose (total dose, 72 µg). Therefore, the results obtained up to now, support the threshold concentration defined by WADA even at higher doses than the recommended therapeutic regime.…”

“…[7][8][9][10] In spite of the high number of pharmacokinetic studies of formoterol in healthy subjects [11][12][13][14] or patients with asthma or COPD, [15] few data on urinary concentrations of formoterol after inhaled administrations are available in the literature to support the threshold value defined by WADA. [16][17][18][19] The objective of this work was to evaluate the threshold concentration of formoterol recently defined by WADA by studying urinary concentrations of the compound in healthy volunteers after inhalation of the maximum allowed dose and in samples from athletes with declared inhaled administration.…”