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could you please send me some information about the difference between
methadon in the pure L-form and its dl-racemat-form. I treat some heroine
patients with pure L-methadon ("L-Polamidon" Hoechst) and I dont manage
tochance the treatment to the cheaper D/L form of methadon.They get
problems and turkeys after some hours. Do you have some ideas, how this
difference can be explained?. They all suffer from C-Hepatitis and AIDS.
Thanks for your advice
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Subject: Re: PharmPK differences between methadon and DL-methadon racema
Date: Thu, 6 May 99 08:39:41 +0100
From: Andrew Sutton
To: "Pharm PK"
In a racemic mixture of 2 enantiomers the common situation is that one is
active and the other is not. This means that 50-50 racemate mixtures
have half the potency of the pure form. Accordingly you should get the
same effect from twice the dose of your cheaper form of heroin.
It could be that the R enantiomer has some potency, in which case the
difference between the 50-50 mixture and the pure L form will be less.
You would then run the risk of an excessive dose if you merely doubled
the L-form dose.
Guildford Clinical Pharmacology
Innovators in Phase 1 model design
and leaders in Phase 2 recruiting.
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From: "Ralph Quadflieg"
Date: Thu, 6 May 1999 14:26:50 +0000
Subject: Re: PharmPK differences between methadon and DL-methadon racemat
As far as I know L-methadone has a 12 time higher analgetic potency
than D-methadone. The racemate has half the analgetic potency than
L-methadone alone. I do not know anything about pharmacokinetic
differences between D- and L-methadone.
I think the solution is dose adjustment according to the analgetic
potency (the racemat should be given twice the dose of the pure L
Don't be disturbed about the mathematics between analgetic power of
the two enantiomeres and the racemat.
Pharmaceutical Technology & Biopharmacy
University of Bonn
An der Immenburg 4
Tel.: ++49 228 73-5117
Fax.: ++49 228 73-5268
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