Drugs to treat chronic conditions are a source of growth for the pharmaceutical industry.
Drugs often become less effective over time because of the increase in liver-metabolizing enzymes.
The liver includes many enzymes to detoxify materials coming into the body.
Modern drugs = highly potent so this is less likely to happen
Drugs, man-made or natural, are foreign substances. Body has mechanisms to deactivate and eliminate.
Some drugs are excreted unchanged in urine. Kidney can recognize foreign substances and remove. This is why the liver and kidneys are most at risk during an overdose. Fat-soluble drugs are removed from the blood quickly and into fat.
Products of metabolism are often toxic themselves.
Ways around this => make drugs more potent so you have to take less of them.
Old days – 1 gm or more of drugs
New days – 10 mg – 100 mg