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Pharmacokinetics of intravenous and oral salbutamol and its sulphate conjugate.
Author(s) -
Morgan DJ,
Paull JD,
Richmond BH,
WilsonEvered E,
Ziccone SP
Publication year - 1986
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1111/j.1365-2125.1986.tb02939.x
Subject(s) - pharmacokinetics , salbutamol , oral administration , conjugate , volume of distribution , pharmacology , medicine , metabolite , urine , chemistry , mathematical analysis , mathematics , asthma
The pharmacokinetics of salbutamol and its sulphate conjugate metabolite were investigated after intravenous and steady‐state oral administration of salbutamol to 10 healthy volunteers. With intravenous administration, total plasma clearance was 480 +/‐ 123 ml min‐1, elimination half‐life was 3.86 +/‐ 0.83 h and apparent volume of distribution was 156 +/‐ 381. Urinary excretion of unchanged drug and sulphate conjugate were 64.2 +/‐ 7.1% and 12.0 +/‐ 3.1% of the dose, respectively. With oral administration, systemic availability was 0.50 +/‐ 0.04, and urinary excretion of unchanged drug and sulphate conjugate were 31.8 +/‐ 1.9% and 48.2 +/‐ 7.3% of the dose, respectively. The drug eliminated on the first‐pass could be accounted for entirely as sulphate conjugate formed, presumably, in the intestinal wall. Renal clearance of salbutamol was 291 +/‐ 70 ml min‐1 after intravenous and 272 +/‐ 38 ml min‐1 after oral administration, while the renal clearance of the sulphate conjugate was 98.5 +/‐ 23.5 ml min‐1 after oral administration. Heart rate increased with increasing plasma salbutamol concentration, although a lag was evident. The effect on heart rate was lower after 24 h continuous oral salbutamol administration.