𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Pharmacokinetics of acetylmethadols II: Plasma levels of D- and L-α-acetylmethadol and their major metabolites in the dog

✍ Scribed by Francis L. S. Tse; Peter G. Welling

Publisher
John Wiley and Sons
Year
1980
Tongue
English
Weight
557 KB
Volume
1
Category
Article
ISSN
0142-2782

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The pharmacokinetics of the synthetic narcotic agent LAAM, its pharmacologically active, demethylated metabolites NORLAAM and DINORLAAM, and also the dextro‐enantiomer DAAM, were examined following intravenous doses of all four compounds, and oral doses of LAAM and DAAM to dogs.

Extensive tissue uptake of all compounds occurred following intravenous doses. NORLAAM penetrated into tissues to a greater extent than LAAM or DINORLAAM and also exhibited the longest biological half‐life (11·7 h) in plasma compared to LAAM (6·5 h) and DINORLAAM (3·6 h). The elimination rate of DINORLAAM was prolonged following oral doses of LAAM and intravenous doses of NORLAAM, and it is suggested that prolonged pharmacologic activity of LAAM may be associated with rate‐limiting demethylation of NORLAAM. DAAM was taken up exrensively by tissues but to a smaller extent than LAAM.

Following oral doses, the bioavailability of LAAM as unchanged drug was 22·6 and 32·5 per cent in two dogs while that of DAAM was 4·9, 9·3, and 14·6 per cent in three dogs. Poor bioavailability of unchanged drug from oral doses appears to be due partly to first‐pass metabolism and is partially compensated for by increased plasma levels of pharmacologically active metabolites.

Extensive tissue uptake of LAAM and its active metabolites, and their long plasma half‐lives, may be partially responsible for the prolonged pharmacologic activity of LAAM reported in patients maintained on this drug.

📜 SIMILAR VOLUMES

Pharmacokinetics of acetylmethadols I: G
Pharmacokinetics of acetylmethadols I: Gas-liquid chromatographic determination of L-α-acetylmethadol and its major metabolites in plasma
✍ Francis L. S. Tse; Peter G. Welling 📂 Article 📅 1980 🏛 John Wiley and Sons 🌐 English ⚖ 296 KB 👁 1 views

## Abstract A gas chromatographic method is reported for simultaneously determining acetyl‐methadol, noracetylmethadol, and dinoracetylmethadol in plasma. Minimum detectable concentrations are 10 ng ml^−1^ for acetylmethadol using a flame ionization detector, and 5 and 25 ng ml^−l^ for noracetylmet

The effect of carbidopa on plasma and mu
The effect of carbidopa on plasma and muscle levels of L-dopa, dopamine, and their metabolites following L-dopa administration to rats
✍ S. Rose; P. Jenner; Prof. C. D. Marsden 📂 Article 📅 1988 🏛 John Wiley and Sons 🌐 English ⚖ 518 KB

Administration of L-dopa (L-3,4-dihydroxyphenylalanine) (200 mg/kg p.o.) to rats produced elevated plasma and muscle concentrations of both L-dopa and 3-O-methyldopa (3-OMD). This effect was potentiated by simultaneous administration of carbidopa (25 mg/kg p.o.). Both L-dopa and 3-OMD accumulated in