One in four patients prescribed drugs their genes may not suit, study finds

Nearly one in four people has been prescribed a medication for which their genetics could have called for a different drug or dose, a new study has found. Researchers at the University of Pittsburgh analysed DNA samples from 98,590 participants, examining 16 genes that affect how the body responds to medications. Among participants with both genetic and clinical data, 24.4 per cent had been prescribed at least one medication that guidelines suggest should have been swapped for another drug or given at a different dose based on their genes. The study did not determine whether patients experienced side effects or poorer outcomes, but researchers say knowing a patient's genetic profile could reduce the trial and error of prescribing. Cost and other barriers currently limit the routine use of such genetic testing, they add. This observational review does not show that one quarter of patients were harmed or that every flagged prescription was wrong. Patients should discuss testing or treatment questions with their prescriber and should not stop or change medication on the basis of this study.