Drug Therapy Gets Personal with Genetic Profiling

Pharmacogenetics Holds Great Promise for Improving Prescribing Practices and Avoiding Adverse Effects

Dana Bartlett, MSN, RN


Am Nurs Journal. 2011;6(5):23-28. 

In This Article

Interplay Between Genetics and Drugs

Why are drugs sometimes ineffective, harmful, or both? We know that age, gender, diet, liver and kidney status, the specific disease being treated (as well as its intensity and duration), concomitant drugs, and environmental factors can influence how well a drug works, what adverse effects are most likely to occur, and which patients a drug is likely to help.

But a growing body of evidence suggests genetics might be one of the most important factors in determining who will and who won't benefit from a particular drug, how much to prescribe, and what adverse effects to expect. By some estimates, genetics may account for 20% to 95% of the variability in how the body handles drugs and what drug effects occur. Evidence supports a genetic predisposition for both expected and unexpected adverse reactions. One major study found incorrect dosing accounted for 42% of adverse reactions while genetic factors caused approximately 50%.

The science of pharmacogenetics focuses on identifying and predicting which drugs are likely to help and which are likely to harm a patient, as well as the proper dosage to prescribe. Researchers in this field study variations in deoxyribonucleic acid (DNA) and ribonucleic acid characteristics as they relate to drug response.