Why do drug dosages have to be changed after a certain amount of time?
i thought the body only builds immunity and starts to resist disease. if a drug helps the body then why does the body start becoming resistant to them?
Let's take a specific example, not with disease but with an injury that involves inflammation whether it is tendonitis or some kind of sprain, etc.
Someone might take an anti-inflammatory whether it is ibuprofen or naproxen sodium to treat this problem. If we assume they are an avid runner, they get some relief from the problem, perhaps they are even icing the injury regularly so they can continue training.
If they continue to take the anti-inflammatory and the problem is not resolved, eventually the body stops producing the anti-inflammatory response it used to because the drug is doing it for them. So they have to take more and more of it for the same effect.
Similar things can happen with other drugs for other problems as well. The body always tries to be as efficient as possible and if something is doing its work for it, it will redirect that energy elsewhere.
It's difficult to assess this in a general sense. Speaking from a position of complete detachment and lack of familiarity with any specific situation, the issue of drug tolerance might come into play. As the body becomes more accustomed to the presence of any drug, more of it might be needed to achieve the desired effect. This might be present in this particular context. If a doctor has prescribed a particular dosage for a condition, over a period of time, the body might have developed a stronger tolerance against it. This would mean that more of the drug, an increase in dosage, might be needed in order to counter the specific effects. However, with this in mind, I think that doctors might have to monitor the situation in order to make sure that another drug might not be in order and to see if the existing drug is actually working. Increasing dosages of a drug that is not working is not good practice, especially if the drug has side effects. This could be one explanation offered, but in specific situations, it is more likely that there are other facts that might necessitate the increase in dosage. Without specifics, we are left with a series of questions.