Why is it that for many substances you gain a tolerance if you take them regularly but you can find one prescription dosage that works for years or life?
Imagine you’re watching the TV and someone puts cotton wool in your ears. You turn the volume up and can hear again.
The body is a dynamic system. Drugs which target receptors on cells, whether antihistamines, antidepressants, anti hypertensives appear to be less effective over time because the cells express, or create, more receptors in response to the suppression by the drug so you need more and more of the drug to block the receptors.
Different medicines work differently. For lots of prescription meds this happens. I’m a GI doctor, and this especially happens with our “promotility” medicines, like erythromycin and cyproheptadine. The same dose gradually wears off. We call it tachyphylaxis. We avoid it by “cycling” meds, going on and then off again for short intervals to reset the system.
Hormone replacement therapy for example replace hormones your body doesn’t produce. You might need more over time if your body gets worse producing than when you are first prescribed, but generally not because you are taking the medication.
Other drugs work in other ways inhibiting or blocking functions in ways your body adapts to. Drugs that work to correct imbalances in particular have your body actively working against them. So over time your body will adapt in various ways to restore what it things is the correct levels. The opposite can also happen.
There’s various other mechanisms, it really comes down to how the drug works and delivers its effects.
Some drugs mimic substances the body produces, or bind to receptors that read those type of substances, and thus block the transmission of signals within the body that might trigger something.
Others drugs might literally train the body to fight pathogens, or enhance certain aspects of the body’s ability to so. Still others might be chemicals that themselves kill pathogens or other dangerous substances in the body.
The list could go on. The point is that “drug” is a term that can describe many, many different things. Because of this, the effects and dosage are going to completely depend on what it actually does within the body. For some things, the body gets better at stopping the drug from working in a misguided attempt to protect itself. For others, it gets too used to the supplemental supply that it stops being good at making the substance itself. There are all kinds of different ways the body builds up what we ultimately label as tolerances. But there are also all kinds of thing that have their effect and the body doesn’t really have a response to it in any way that makes it less effective over time.
It really just depends on exactly what the drug is doing.
In a general sense drugs that have some affect like meth, or opioids that you can feel and get addicted to will result in you taking them more. This can happen with anti-anxiety meds too by the way. After a while they become less affective because the brain tries to get back to its normal homeostasis. If taking meth and speeding along all the time the brain is going to try to get things back to normal. It will do so by down regulating the receptor. This then requires you to take more for the same affect, it down regulates more, and before you know it the drug doesn’t work anymore, but you are now addicted and are going to have an unpleasant experience for a while when you stop taking them called withdrawals. What happens here is you removed to source that is altering the brain chemistry but the brain has down regulated the relevant receptors so stopping the drug will swing you the other way. Not only do you not have that artificial stimulation, but your natural brain stimulation has been down regulated to compensate for too much. This does not immediately return to normal so you feel miserable for a while. But again the brain wants that homeostasis so now with too little simulation it will gradually start up regulating your natural abilities but this take time. This is basically what happens when you recover from drug addiction. Once your brain it back to it normal activity your withdrawals will be done (assuming no permanent damage).
But this is not the only way drugs work, other drugs may result in down regulation of he receptor and this has no “high” associated with it, but can be beneficial for mental health. Certain antidepressants will down regulate some HT-2 receptors which is actually believed to be part of the benefit of these drugs. But this takes time and the benefits will be noticed after a while of taking it when the receptor gets down regulated, and some depression related symptoms start to ease. Note this is but one of many receptors just using this one as a specific example of down regulation being the goal and something that improves your mental state or so it is theorized.
Other drugs for other purposes may not work like this. If your body is not making enough thyroid hormone in this case the purpose is to replace it to get it to normal levels and that is the goal and what results in therapeutic benefit.
These are some simplified examples. Drugs of abuse can work like the first and legally prescribed benzos can act similarly to the illicit drugs people get high from. . Sometimes drugs that have no high may change receptor expression and that is the benefit. As long as you keep taking he drug the receptor will remain down regulated and provide a more subtle mental benefit than a “high”. Others work different still. And there are even more things that go on but this gives you a few simple examples.
Most of the time prescription drugs are taken I amounts that restore the patient’s body to what the body itself considers normal. While recreational drugs are taken in amounts that pushes the body off what the body considers normal and so the body adapts.
The drug could work in a way that the body can’t adapt to. Example one of the primary drugs classes for depression is SSRI(Selective Serotonin Reuptake Inhibitor). The body might not be able to adapt to that class of drug because reuptake is the primary mechanism the body uses to get rid of “excess” Serotonin (I don’t know if this is true I am just using it as an example to illustrate the idea).
The drug actually has lost effectiveness but worked long enough for the body to recalibrate and the patient is just taking the drug out of habit. So it seems like the drug didn’t lose effectiveness because the underlying problem also lessened.
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Imagine you’re watching the TV and someone puts cotton wool in your ears. You turn the volume up and can hear again.
The body is a dynamic system. Drugs which target receptors on cells, whether antihistamines, antidepressants, anti hypertensives appear to be less effective over time because the cells express, or create, more receptors in response to the suppression by the drug so you need more and more of the drug to block the receptors.
Different medicines work differently. For lots of prescription meds this happens. I’m a GI doctor, and this especially happens with our “promotility” medicines, like erythromycin and cyproheptadine. The same dose gradually wears off. We call it tachyphylaxis. We avoid it by “cycling” meds, going on and then off again for short intervals to reset the system.
Because not all drugs work the same way.
Hormone replacement therapy for example replace hormones your body doesn’t produce. You might need more over time if your body gets worse producing than when you are first prescribed, but generally not because you are taking the medication.
Other drugs work in other ways inhibiting or blocking functions in ways your body adapts to. Drugs that work to correct imbalances in particular have your body actively working against them. So over time your body will adapt in various ways to restore what it things is the correct levels. The opposite can also happen.
There’s various other mechanisms, it really comes down to how the drug works and delivers its effects.
Some drugs mimic substances the body produces, or bind to receptors that read those type of substances, and thus block the transmission of signals within the body that might trigger something.
Others drugs might literally train the body to fight pathogens, or enhance certain aspects of the body’s ability to so. Still others might be chemicals that themselves kill pathogens or other dangerous substances in the body.
The list could go on. The point is that “drug” is a term that can describe many, many different things. Because of this, the effects and dosage are going to completely depend on what it actually does within the body. For some things, the body gets better at stopping the drug from working in a misguided attempt to protect itself. For others, it gets too used to the supplemental supply that it stops being good at making the substance itself. There are all kinds of different ways the body builds up what we ultimately label as tolerances. But there are also all kinds of thing that have their effect and the body doesn’t really have a response to it in any way that makes it less effective over time.
It really just depends on exactly what the drug is doing.
In a general sense drugs that have some affect like meth, or opioids that you can feel and get addicted to will result in you taking them more. This can happen with anti-anxiety meds too by the way. After a while they become less affective because the brain tries to get back to its normal homeostasis. If taking meth and speeding along all the time the brain is going to try to get things back to normal. It will do so by down regulating the receptor. This then requires you to take more for the same affect, it down regulates more, and before you know it the drug doesn’t work anymore, but you are now addicted and are going to have an unpleasant experience for a while when you stop taking them called withdrawals. What happens here is you removed to source that is altering the brain chemistry but the brain has down regulated the relevant receptors so stopping the drug will swing you the other way. Not only do you not have that artificial stimulation, but your natural brain stimulation has been down regulated to compensate for too much. This does not immediately return to normal so you feel miserable for a while. But again the brain wants that homeostasis so now with too little simulation it will gradually start up regulating your natural abilities but this take time. This is basically what happens when you recover from drug addiction. Once your brain it back to it normal activity your withdrawals will be done (assuming no permanent damage).
But this is not the only way drugs work, other drugs may result in down regulation of he receptor and this has no “high” associated with it, but can be beneficial for mental health. Certain antidepressants will down regulate some HT-2 receptors which is actually believed to be part of the benefit of these drugs. But this takes time and the benefits will be noticed after a while of taking it when the receptor gets down regulated, and some depression related symptoms start to ease. Note this is but one of many receptors just using this one as a specific example of down regulation being the goal and something that improves your mental state or so it is theorized.
Other drugs for other purposes may not work like this. If your body is not making enough thyroid hormone in this case the purpose is to replace it to get it to normal levels and that is the goal and what results in therapeutic benefit.
These are some simplified examples. Drugs of abuse can work like the first and legally prescribed benzos can act similarly to the illicit drugs people get high from. . Sometimes drugs that have no high may change receptor expression and that is the benefit. As long as you keep taking he drug the receptor will remain down regulated and provide a more subtle mental benefit than a “high”. Others work different still. And there are even more things that go on but this gives you a few simple examples.
Most of the time prescription drugs are taken I amounts that restore the patient’s body to what the body itself considers normal. While recreational drugs are taken in amounts that pushes the body off what the body considers normal and so the body adapts.
The drug could work in a way that the body can’t adapt to. Example one of the primary drugs classes for depression is SSRI(Selective Serotonin Reuptake Inhibitor). The body might not be able to adapt to that class of drug because reuptake is the primary mechanism the body uses to get rid of “excess” Serotonin (I don’t know if this is true I am just using it as an example to illustrate the idea).
The drug actually has lost effectiveness but worked long enough for the body to recalibrate and the patient is just taking the drug out of habit. So it seems like the drug didn’t lose effectiveness because the underlying problem also lessened.