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Pharmacokinetics and metabolism of salbutamol in premature labour.
Author(s) -
Hutchings MJ,
Paull JD,
WilsonEvered E,
Morgan DJ
Publication year - 1987
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.1365-2125.1987.tb03138.x
Subject(s) - salbutamol , pharmacokinetics , medicine , oral administration , urine , endocrinology , asthma
1 The pharmacokinetics of salbutamol and its sulphate conjugate were examined during intravenous and steady‐state oral administration in nine patients receiving the drug for the prevention or treatment of premature labour. 2 Uterine contractions were inhibited by plasma salbutamol concentrations in the range 8‐33 ng ml‐1 in six of the seven patients who were receiving intravenous drug. 3 By comparison with our previous study in a control group of healthy males and nonpregnant females, the total clearance of salbutamol in premature labour (501; s.d. 185 ml min‐1) was similar to that in the control group (480; s.d. 123 ml min‐1). Renal salbutamol clearance (208; s.d. 51 ml min‐1), however, was significantly less than that in the control group (283; s.d. 51 ml min‐1). 4 The systemic availability (n = 3), urinary recovery of unchanged oral salbutamol and area under the plasma curve during the oral dosage interval (n = 5) were all only slightly lower (10‐20%) than control values, suggesting slightly lower oral absorption. 5 Formation and elimination of the sulphate conjugate were similar to those observed in control subjects suggesting that first‐ pass sulphation in the gut wall is unchanged in pregnancy. Overall there were only minor differences in salbutamol pharmacokinetics between control subjects and patients in premature labour.