For example, people on medication to control high blood pressure must be careful if they take ephedrine for nasal congestion because it can raise blood pressure. How drugs interact There are several ways in which drug interactions can take place. Drug A might interfere with the way drug B is absorbed into the bloodstream through the gut. Or drug A might block the metabolism, or the breakdown, of drug B by the liver. Drug A might block drug B from being eliminated from the urine.
Drugs can also interact at the cell level.
For example, one drug may push the other drug off the cell and make it less effective. There are a number of other kinds of interactions. Precautions When a new medication is prescribed, a person should tell his or her healthcare provider what other drugs he or she is taking. To avoid serious drug interactions, it's important to mention medications that have been prescribed by other healthcare providers. All drugs and substances are important to mention.