The older brain is far more sensitive to all drugs that cross the blood-brain barrier. The list of medications that cause confusion or changes to the central nervous system in older people is very long. Still, the more drugs that are taken, the more likely there will be a medication-related problem. The average nursing home resident takes eight to ten medications, putting such a person at even greater risk for medication-related problems. But in his pocket he always carried a little pad of camphor that he inhaled deeply when no one was watching, to calm his fear of so many medicines mixed together.
Medicines sometimes cause side effects that then require another medicine.
We give a patient a diuretic that causes a decrease in potassium levels. We give a potassium supplement that causes indigestion. We give a medication for the indigestion caused by the potassium supplement. The first responsibility is to ensure that all of a patient's medication therapy is appropriately indicated, the most effective available, the safest possible, and that it can be taken as intended. These are the issues that must be considered every time we either prescribe, give, or take a medication.