There are currently a few tests already available that can assist in predicting whether individual cancer patients are likely to have a bad reaction or favorable response to certain medications. Certain other diseases can also benefit from these tests. Some medications have also been studied, such as proton pump inhibitors, warfarin, antidepressants, and anticoagulants.
Some patients break down medications too quickly which does not allow the medications to fully work, while other patients do not break down the medications quickly enough, resulting in the medications building up in the body and causing the patient to experience severe side effects. A test that examines the cytochrome P450 group of enzymes, a group of enzymes responsible for metabolizing, referred to as the CYP450 test can help with this. This test is used to determine if an individual has these genetic variations. This allows doctors to make a more informed decision when deciding which medication, or medications, to prescribe a patient. This results in an increased chance that the treatment will be successful and a decreased chance that the patient will experience side effects and other adverse events.