Biomaterial Database

Enantioselective disposition of salbutamol in man following oral and intravenous administration. 1996

D W Boulton, and J P Fawcett

School of Pharmacy, University of Otago, Dunedin, New Zealand.

1 Salbutamol is a beta 2-adrenoceptor stimulant used clinically as a racemate where the activity resides predominantly in the (-)R enantiomer with little or no activity attributed to the (+)S enantiomer. Salbutamol undergoes extensive pre-systemic metabolism and active renal excretion. 2 The pharmacokinetics of the enantiomers of salbutamol have been investigated after intravenous (1.6 mg) and oral (4 mg) dosing with racemic drug to seven normal male volunteers. Plasma and urine samples were analysed by chiral h.p.l.c. after solid phase extraction. 3 The ratio of (-)R/(+)S salbutamol in plasma and urine following intravenous administration ranged from near unity soon after dosing to about 0.66 after 8 h. The ratio remained at about 0.3 in both plasma and urine over the 8 h following an oral dose. 4 The following pharmacokinetic parameters for (+)S and (-)R salbutamol were found to be significantly different (P < 0.05) after intravenous administration (clearance 0.39 +/- 0.12 vs 0.62 +/- 0.18 1 h-1 kg-1, terminal phase half-life 2.85 +/- 0.83 vs 2.00 +/- 0.49 h, amount excreted unchanged in urine 55 +/- 11 vs 46 +/- 8%) and following oral administration (amount excreted unchanged in urine 32 +/- 11 vs 8 +/- 4% and bioavailability 0.71 +/- 0.09 vs 0.30 +/- 0.07). 5 The active (-)R enantiomer of salbutamol undergoes significantly faster metabolism in man than the inactive (+)S enantiomer resulting in considerably lower bioavailability of the active enantiomer following oral administration.

UI	MeSH Term	Description	Entries
D007262	Infusions, Intravenous	The long-term (minutes to hours) administration of a fluid into the vein through venipuncture, either by letting the fluid flow by gravity or by pumping it.	Drip Infusions,Intravenous Drip,Intravenous Infusions,Drip Infusion,Drip, Intravenous,Infusion, Drip,Infusion, Intravenous,Infusions, Drip,Intravenous Infusion
D008297	Male		Males
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D006339	Heart Rate	The number of times the HEART VENTRICLES contract per unit of time, usually per minute.	Cardiac Rate,Chronotropism, Cardiac,Heart Rate Control,Heartbeat,Pulse Rate,Cardiac Chronotropy,Cardiac Chronotropism,Cardiac Rates,Chronotropy, Cardiac,Control, Heart Rate,Heart Rates,Heartbeats,Pulse Rates,Rate Control, Heart,Rate, Cardiac,Rate, Heart,Rate, Pulse
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000284	Administration, Oral	The giving of drugs, chemicals, or other substances by mouth.	Drug Administration, Oral,Administration, Oral Drug,Oral Administration,Oral Drug Administration,Administrations, Oral,Administrations, Oral Drug,Drug Administrations, Oral,Oral Administrations,Oral Drug Administrations
D000318	Adrenergic beta-Agonists	Drugs that selectively bind to and activate beta-adrenergic receptors.	Adrenergic beta-Receptor Agonists,beta-Adrenergic Agonists,beta-Adrenergic Receptor Agonists,Adrenergic beta-Agonist,Adrenergic beta-Receptor Agonist,Betamimetics,Receptor Agonists, beta-Adrenergic,Receptors Agonists, Adrenergic beta,beta-Adrenergic Agonist,beta-Adrenergic Receptor Agonist,Adrenergic beta Agonist,Adrenergic beta Agonists,Adrenergic beta Receptor Agonist,Adrenergic beta Receptor Agonists,Agonist, Adrenergic beta-Receptor,Agonist, beta-Adrenergic,Agonist, beta-Adrenergic Receptor,Agonists, Adrenergic beta-Receptor,Agonists, beta-Adrenergic,Agonists, beta-Adrenergic Receptor,Receptor Agonist, beta-Adrenergic,Receptor Agonists, beta Adrenergic,beta Adrenergic Agonist,beta Adrenergic Agonists,beta Adrenergic Receptor Agonist,beta Adrenergic Receptor Agonists,beta-Agonist, Adrenergic,beta-Agonists, Adrenergic,beta-Receptor Agonist, Adrenergic,beta-Receptor Agonists, Adrenergic
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000420	Albuterol	A short-acting beta-2 adrenergic agonist that is primarily used as a bronchodilator agent to treat ASTHMA. Albuterol is prepared as a racemic mixture of R(-) and S(+) stereoisomers. The stereospecific preparation of R(-) isomer of albuterol is referred to as levalbuterol.	Salbutamol,2-t-Butylamino-1-(4-hydroxy-3-hydroxy-3-hydroxymethyl)phenylethanol,Albuterol Sulfate,Proventil,Sultanol,Ventolin
D013237	Stereoisomerism	The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)	Molecular Stereochemistry,Stereoisomers,Stereochemistry, Molecular,Stereoisomer