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4-fluoroamphetamine metabolites

I'd wager the majority of it would be excreted unchanged, while the main metabolite would be 4-Fluoro-norephedrine (hydroxyl in the beta position).

Of interest:
Metabolic activation of the serotonergic neurotoxin para-chloroamphetamine to chemically reactive intermediates by hepatic and brain microsomal preparations.

Miller KJ, Anderholm DC, Ames MM.

Para-chloroamphetamine (PCA) is selectively toxic to serotonergic neurons in laboratory animals. Acute, reversible neurotoxicity is followed by long-term effects which include inactivation of tryptophan hydroxylase and destruction of neurons. We have studied the metabolic formation of reactive intermediates that might be involved in long-term PCA neurotoxicity. Incubation of [3H]PCA with rat hepatic microsomes resulted in NADPH-dependent and oxygen-dependent covalent binding of radioactivity to microsomal protein. Addition of SKF-525A and glutathione to incubation mixtures inhibited [3H]PCA covalent binding 30% and 92% respectively. No inhibition of radiolabeled covalent binding was observed in an atmosphere of carbon monoxide/oxygen (80/20). 7,8-Benzoflavone was more effective than metyrapone in inhibiting [3H]PCA covalent binding. The extent of [3H]PCA covalent binding to microsomal protein was unchanged after phenobarbital pretreatment of rats, whereas 3-methylcholanthrene pretreatment increased [3H]PCA covalent binding (175%). NADPH-dependent and oxygen-dependent covalent binding of radioactivity was also observed when [3H]PCA was incubated with rat brain microsomal preparations. Addition of SKF-525A and glutathione to incubation mixtures inhibited covalent binding 10 and 40% respectively. There were no significant differences in total, NADPH-independent or NADPH-dependent covalent binding of radiolabeled R,S(+/-)-, R(-)-, or S(+)-PCA to rat hepatic microsomal protein. Less covalent binding was observed when [3H]amphetamine was incubated with rat liver microsomal preparations as compared to results with [3H]PCA. Minimal covalent binding was observed when [3H]PCA was incubated with liver microsomal preparations from rabbits, a species resistant to PCA neurotoxicity. Results of these metabolism studies are consistent with the hypothesis that oxidative metabolic activation of PCA to reactive and toxic metabolites is related to the long-term neurotoxicity of this agent.
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http://www.ncbi.nlm.nih.gov/pubmed/3707603

Comparison of 4-chloro-, 4-bromo- and 4-fluoroamphetamine in rats: Drug levels in brain and effects on brain serotonin metabolism

R. W. Fuller, J. C. Baker, K. W. Perry and B. B. Molloy

The Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46206, USA

The ability of 4-chloroamphetamine, 4-bromoamphetamine, and 4-fluoroamphetamine to deplete brain 5-hydroxyindoles and some pharmacokinetic properties of these drugs were compared in rats. Half-lives of the three compounds in rat brain were 3.7, 4.4, and 5.7 hr, respectively for the 4-fluoro, 4-chloro, and 4-bromo amphetamines. The tendency of the drugs to be associated with paniculate material in brain homogenates or to prefer an organic versus an aqueous phase in vitro varied in the order 4-bromo > 4-chloro > 4-fluoro. This order of activity also applied to the inhibition of monoamine oxidase in vitro. All three 4-haloamphetamines reduced the activity of tryptophan hydroxylase and lowered the levels of serotonin and 5-hydroxyindoleacetic acid in whole brain initially. With 4-chloroamphetamine and 4-bromoamphetamine, the depletion of brain 5-hydroxyindoles lasted for at least a week. 4-Fluoroamphetamine, in contrast, lowered serotonin and 5-hydroxyindoleacetic acid levels only for short times (2–6 hr) after drug injection, and 5-hydroxyindole levels were essentially back to normal within 24 hr. Prior treatment with an uptake inhibitor prevented the serotonin depletion by all of the haloamphetamines, indicating they all required the membrane uptake pump for entry into the neurone. The effect of 4-bromoamphetamine, like that of 4-chloroamphetamine, could be reversed by subsequent injection of the uptake inhibitor after short periods but not after 24–48 hr. The failure of 4-fluoroamphetamine to produce a long-lasting depletion of brain serotonin like that produced by 4-chloroamphetamine or 4-bromoamphetamine may reflect the inability of the fluoro-compound to be metabolized in the same way as the other haloamphetamines.
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http://www.ncbi.nlm.nih.gov/pubmed/1196472
 
And one more:
Psychostimulant-like effects of p-fluoroamphetamine in the rat.

Marona-Lewicka D, Rhee GS, Sprague JE, Nichols DE.

Departments of Pharmacology and Toxicology, and Medicinal Chemistry and Pharmacognosy, Purdue University, West Lafayette, IN 47907, USA.

The present study was undertaken to compare the pharmacological properties of p-fluoroamphetamine with those of amphetamine and of other halogenated amphetamines, using several in vivo and in vitro tests. These included substitution testing in (+)-amphetamine (1 mg/kg, 5.4 mu mol/kg, i.p.)-, (+)-N-methyl-1-(1,3-benzodioxol-5-yl)-2-butanamine [(+)-MBDB] (1.75 mg/kg, 7.8 mu mol/kg, i.p.)-, and 5-methoxy-6-methyl-2-aminoindan (MMAI) (1.71 mg/kg, 8 mu mol/kg, i.p.)-trained rats, [3H]5-HT and [3H]dopamine uptake inhibition in whole brain synaptosomes, and changes in striatal extracellular levels of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) as measured by in vivo microdialysis in freely moving rats. In drug discrimination substitution tests, p-fluoroamphetamine fully mimicked (+)-amphetamine (ED50 0.43 mg/kg, 2.11 mu mol/kg), whereas 'no substitution' was observed in rats trained to discriminate the serotonin (5-hydroxytryptamine, 5-HT)-releasing agents (+)-MBDB or MMAI from saline. p-Chloroamphetamine did not substitute for amphetamine but fully substituted for the (+)-MBDB and MMAI cues (ED50 0.17 mg/kg, 0.82 mu mol/kg, and 0.14 mg/kg, 0.69 mu mol/kg, respectively). p-Fluoroamphetamine, in comparison with p-chloroamphetamine and p-iodoamphetamine, showed much stronger inhibition of [3H]dopamine than [3H]5-HT uptake into rat brain synaptosomes but was less selective than amphetamine. p-Fluoroamphetamine (7.0 mg/kg, i.p.), 1 h after administration, strongly elevated (849% of baseline) extracellular dopamine in rat striatum measured using in vivo microdialysis. Amphetamine (2 mg/kg, i.p.) increased extracellular dopamine in rat striatum with a maximum at the same time as did p-fluoroamphetamine, but the latter gave a smaller increase. The data presented suggest that p-fluoroamphetamine resembles amphetamine more than it does the 5-HT-releasing type amphetamines.
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http://www.ncbi.nlm.nih.gov/pubmed/8749023
 
I was also under the impression that the flourophenyl group would be excreted unchanged. I was mostly curious as to whether it shared any metabolites with amphetamine, and if you're correct then it doesn't.
 
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Well, norephedrine is a metabolite of amphetamine. The para-halo group prevents the ring hydroxylation from occurring. I'm guessing on the metabolites based on para-chloroamphetamine metabolism.

I'm not completely sure how correct the conclusion second of the study is. It may just reflect upon 4-Fluoroamphetamine's inability to release serotonin (as stated in the third study).
 
4-fluoro-norephedrine would never become norephedrine in the human body though right?
 
I would doubt it, the halogenated rings tend to stay put in the human body. The fluorine bond to the phenyl ring is very strong compared to the other halogens as well.
 
As mentioned above, the 4-fluoro moiety prevents the formation of a major amphetamine metabolite, 4-hydroxyamphetamine. The other significant metabolites of dextroamphetamine in humans are: benzoic acid and (less so) norephedrine. So, I bet these become 4-fluoro-benzoic acid and 4-fluoro-norephedrine in the case of 4-fluoroamphetamine. Thankfully, the para-fluoro moiety is pretty much inert. I've always wondered what 3,4-difluoroamphetamine would be like--Roman et al (2004) claims that it is a fairly weak inhibitor of [3H]5-HT uptake, supposedly it isn't an MAO-A inhibitor and both 3-fluoro- and 4-fluoro-amphetamine are quite active at the DAT, so it is probably quite a nice compound.
 
Not discussing the synthesis, but 3,4-difluoroamphetamine should be an easy one to make.
 
nuke said:
I would doubt it, the halogenated rings tend to stay put in the human body. The fluorine bond to the phenyl ring is very strong compared to the other halogens as well.
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I know this is slightly off topic, but I always hear about so many drugs that leave things behind, when you say "stay put" you don't mean forever do you? Where could it deposit itself that it wouldn't be cleared out eventually (through apoptosis of whatever cell it is chillen in/around if worst comes to worse, unless its simply floating around your fluids). Every time people have told me that drugs leave things behind like that I have usually skoffed, because usually it is people saying something along the lines of "DUDE, acid stays in your spine like FOREVER! And if you crack your back, you start trippin balls!!" (wait... thats not true right?). Thanks for any answers (or links to reading are good too) I get :)
 
^^No psychoactive drug stays in your body forever--after about 7-8 half-lives, the concentration is effectively no different than zero. There are some highly lipophilic industrial pesticides that can be absorbed into fat cells and remain there for a period of months (at least). Clearly, these are not things that anyone would willingly ingest--as you can imagine, most of them are potent carcinogens.

The longest-lasting psychoactive compounds (in terms of being retained in adipocytes) are the cannabinoids. I think THC has a terminal half-life of 1-7 days (depending upon whether it is acutely or chronically administered), so it can be detectable for up to a month after the last administration.

The idea that LSD remains in your system for decades is nothing but a giant, steaming load of horseshit, as is the idea that LSD can spontaneously cause a full-on psychedelic experience years after dosing.
 
I was referring to the ability of the fluorine to stay attached the aryl ring -- it won't break off at any time inside your body.
 
does it comes as crystals and does it look the same.
LIke is there any way u can figure out like with meth if its been cut.
what does it look like compared to meth... i know thats vagues cause i seen meth ranging in all colours, tastes, forms and shapes
 
Ring hydroxylation though could happen on different positions than 4?!
 
hugo24 said:
Ring hydroxylation though could happen on different positions than 4?!
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It could, but it doesn't seem to happen with p-chloroamphetamine. One of the major metabolites remains unidentified, though.
 
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