The therapeutic dose range formoterol is between 12 mg to 24 mg 2 times a day. Data on the pharmacokinetics of formoterol obtained from healthy volunteers after inhalation of formoterol at doses higher than the recommended range and patients after inhalation of formoterol at therapeutic doses. Suction. After a single inhalation of formoterol fumarate at a dose of 120 mg to healthy volunteers formoterol rapidly absorbed into the plasma, the maximal concentration of formoterol in plasma tren achieved within 5 minutes after inhalation. Patients receiving formoterol in a dose of 12 or 24 mg 2 times a day for 12 weeks, the formoterol concentration in the plasma, measured after 10 minutes, 2 hours or 6 hours after inhalation are in the ranges , respectively. in the studies that investigated the total excretion of formoterol and its enantiomers urine, it was shown that the amount of formoterol in the systemic circulation is increased proportional to the inhaled dose (12-96 ug). After administration by inhalation at a dose of formoterol 12 or 24 mg 2 times a day for 12 weeks formoterol unchanged excretion in urine in patients with bronchial asthma increased , and in patients .
This indicates that some of its cumulation in plasma after multiple inhalations. Thus it is not mentioned more accumulation of one enantiomer of formoterol over another after repeated inhalations. Just as it was reported for other drugs used in the form of inhalation, a large part of formoterol applied using the inhaler will be swallowed and then absorbed from the the gastrointestinal tract tren. When assigning 80 mcg formoterol 3H-labeled two healthy volunteers inside absorbed at least 65% of formoterol. Binding to plasma proteins and distribution. Formoterol Binding to plasma proteins is 61-64%, the serum albumin binding – 34%. The range of concentrations celebrated after application of therapeutic doses, saturation of binding sites is not achieved. metabolism. The main route of metabolism of formoterol is the direct conjugation with glucuronic acid. Another pathway – O-demethylation followed by conjugation with glucuronic acid (glyukoronidatsiey). Insignificant pathway include the conjugation of formoterol sulphate followed deformilirovaniem. Many isoenzymes are involved in the process of glucuronidation and of formoterol, suggesting a low potential for drug interaction through inhibition kakogo- or isoenzyme participating in the metabolism of formoterol. At therapeutic concentrations formoterol does not inhibit isozymes of cytochrome . Excretion. In patients with asthma and tren is treated with formoterol fumarate in a dose of 12 or 24 mg 2 times a day for 12 weeks, about 10% and 7% of the dose was determined in the urine, respectively, formoterol as unchanged. The calculated proportion enantiomers of formoterol unchanged in urine are 40% and 60%, respectively, after a single dose of formoterol (12-120 mg) in healthy volunteers after single and repeated doses of formoterol in asthmatic patients. The active substance and its metabolites are completely eliminated from the body; about 2/3 of the oral dose excreted in the urine used, 1/3 – with the feces. Renal clearance of formoterol is 150 ml / min. In healthy volunteers formoterol terminal half-life of plasma after a single inhalation of formoterol fumarate in a dose of 120 micrograms of 10 hours; terminal enantiomers calculated from the urinary excretion accounted for 13.9 and 12.3 hours, respectively.
Sex After correction for pharmacokinetic parameters formoterol body mass in men and women do not have significant differences. elderly patients pharmacokinetics of formoterol has not been studied in elderly patients. Pediatrics in a clinical study in children aged 5-12 years with asthma who received formoterol fumarate in a dose of 12 or 24 mg 2 times a day for 12 weeks , excretion of unchanged formoterol in the urine increased by 18-84% compared with the corresponding value measured tren after the first dose. in clinical studies in children in the urine accounts for about 6% of unchanged formoterol. patients with impaired hepatic and / or renal impairment The pharmacokinetics of formoterol in patients with impaired liver and / or renal impairment has not been studied.