Amphetamine's effect on drug metabolism

[SpunkySkunk347]

Some sources state that amphetamine will cause drugs like THC to metabolize quicker and decrease levels found in urine. How exactly does amphetamine "speed up metabolism"?

What about for drugs like methadone? If an opiate user had say, taken a dose of 30mg methadone, and then taken a dose of amphetamine several days later, would this shorten the half-life of the methadone remaining in the system and allow the opiate user to take other opiates sooner than they normally could have without methadone blocking its effects?

For example,
an opiate user takes a dose of 30mg methadone on day 1.
This individual would normally have to wait 5-7 days after taking methadone in order to feel other opiates, such as oxycodone.
But, if a dose of amphetamine was taken during that period, would that shorten the amount of time the individual normally had to wait to feel other opiates, say maybe only 3-6 days of waiting instead of 5-7 days?

Any feedback appreciated

 

[SpunkySkunk347]

As far as 'metabolism' goes in the exercising dieter's weight loss sense, I'm convinced that all amphetamine does to aid in weight loss is:
A) Cause the user to no longer want to eat, resulting in the body using its own fat for energy instead of eating food for energy.
B) Causes the user to sweat/urinate more frequently than normal, resulting in a loss of water-weight which is perceived by the user as a loss of body fat (when in reality, it isn't, and is gained back almost instantly as soon as the user resumes normal eating patterns).
C) Increased willpower, motivation, and confidence, allowing the user to stick to their diet plans more vigorously.
D) Increased physical activity resulting simply from amphetamine stimulating the individual causing them to fidget and do more physical tasks- and hence, the body burns more calories.

But does amphetamine directly increase metabolism? And is drug metabolism the same type of metabolism in the dieter's sense of the word?

 

[Nagelfar]

It speeds up metabolism in a very direct and simple sense: it increases everything from heart rate to by-passing/resetting circadian rhythms. The sped up biological clock is from a faster "clock rate" as it were, synapses are firing faster, adrenergic systems are attenuated and sped up. The entire body's central control of cytogenesis to apoptosis is sped up; this is the very definitional basis of metabolism.

In terms of opiate tolerance it will bring one to withdrawal faster, and therefore require redosing sooner.

 

[SpunkySkunk347]

Very good reply, that was exactly the information I was looking for.

Information regarding methadone use in particular is the main reason why I personally made this thread, so before I get on to the body of my reply I was wondering if you could give any more information regarding amphetamine's effect on opiate metabolism in particular. Will amphetamine use result in a hastened metabolism of methadone? Methadone is well known to block the effects of lesser opiates; would taking amphetamine after taking methadone shorten the period of time that methadone blocks other opiate's effects?

When it comes to liver enzymes, would it be safe to say amphetamine use results in an induction of enzymes?
What about for someone who has a several year long tolerance to amphetamines - would they still experience a "sped up metabolism" that a first-time user would experience?

I suppose I could answer my questions a lot easier if I had taken college courses on the subject matter, but I have little more than a high school education and an enthusiastic interest in pharmacodynamics, pharmacokinetics, and psychoactives (I'd say I'm quite a few steps above the layman, but still not quite at the level of a post-grad organic chemist). Just speak at whatever technical level you're used to, and I can decipher the rest with the aid of google and wikipedia.

 

[Nagelfar]

I'm at the same level as you for the most part, just a lot of self-study. From what I know with the mechanism of direct CNS stimulation inherent in the effects of amphetamines, as long as there are subjective effects, that sped up metabolism is there; tolerance or not.

The only reason methadone blocks the effects of other, shorter acting / lower affinity opioids is because it allows/lets your body adjust its baseline to its own relatively more persistent mu-receptor agonism/activation. Which it has due to being longer lasting & higher affinity as a formulation/molecular-conformation than more common abusable opioids.

So the answer is not straight forward. The experience of slight withdrawal itself is the best indicator that a dose of a shorter acting opioid, morphine-based or such, would work. But the methadone habituated body is used to a sustained agonism of the mu receptors, and the blood plasma levels of the longer lasting opioids (i.e. methadone) would be more slowly diminished than what the shorter acting one would deliver if it were to be administered (e.g. morphine, heroin, oxycodone). Which may make withdrawal from its subsequent dose perhaps more or perhaps less noticeable since your body is calibrated to expect a longer duration of action upon discontinuation of one to the other. Either way, it depends on how your own specific body reacts, and may vary.

However, amphetamines will invariably bring the duration needed to wait in order to feel a redose of an opiate down, regardless of that opiate, unless its the extremely unlikely case that the specific amphetamine in question is non-traditional and somehow has opioid activity in itself.