As we get older, our bodies change in ways that can affect how we process medicines. For older patients, these changes can really impact how they absorb, distribute, break down, and get rid of drugs. Let’s break this down into simpler parts:

1. Absorption Changes:

   • As we age, our stomach produces less acid. This can affect how well some medicines dissolve and are absorbed.
   • Older folks may have slower stomach emptying and less blood flow in their digestive system. This can make it take longer for medicines to be absorbed.

2. Distribution:

   • With age, the amount of body fat increases while muscle mass goes down. This affects how fat-soluble (lipophilic) and water-soluble (hydrophilic) drugs are spread throughout the body.
   • Older adults may also have less water in their body, which can lead to higher levels of water-soluble medicines in their blood.

3. Metabolism:

   • The liver often doesn’t work as well as it used to when we age. This can result in less blood flow and fewer enzymes to break down medicines. Drugs that go through phase I metabolism (the first step of how the body processes drugs) might last longer and can be more likely to cause side effects.
   • However, phase II reactions (like conjugation) usually still work fine in older patients, but there can be differences from person to person.

4. Excretion:

   • Kidney function usually gets worse with age, which means the kidneys might not clear out medicines as well. This can lead to the risk of too much medicine building up in the body, causing harmful effects. It’s very important to adjust medications based on how well the kidneys are working.

In summary, because of these changes, doctors need to be very careful when prescribing medicines to older adults. They should look closely at these factors and make adjustments to treatment plans. This way, older patients can get the safest and most effective care possible.