Genetic Testing

Many inquire if they can have genetic testing to predictive they may tolerate certain benzodiazepines. The answer is both yes and no. There have been developments in medicine and science very recently called pharmacogenomics—the study of how genes affect a person’s response to medicines. Pharmacogenomic testing is a support tool that allows for patients to have their genes analyzed prior to taking medications to see how their genes affect the way their body will respond to the medications.

This tool is not as useful for someone who is already physically dependent on and having adverse effects from the medication, except to perhaps explain why the medication might be ill-tolerated. It can be used if the patient wishes to crossover to a different, often longer acting benzodiazepine to taper. This tool can help predict drug compatibility and metabolism speed, which may lead to proper dosing to prevent interdose withdrawal. This testing does not determine whether a patient will become physically dependent on benzodiazepines, experience withdrawal upon cessation, nor can it predict the likelihood of developing a protracted withdrawal syndrome. No matter the results is important to stick with the prescribing guidelines, which recommend short term use only (2 to 4 weeks).

Anyone considering taking psychotropic medications like benzodiazepines or SSRIs (or any of the other medications for that matter that can be tested for like opiates, NSAIDs, cardiac drugs, etc.) should consider having pharmacogenomic testing done prior to initiating the medication. The testing can cost a few thousand dollars out of pocket, so it is important to call whichever company you decide to use prior to having the testing to determine if it is covered by insurance or if the testing company offers a sliding scale payment program. Most of the testing companies also require the test to be ordered by a licensed healthcare professional.

GeneSight pharmacogenomic testing is one company that is utilized in the United States to perform the testing, although there are many. GeneSight’s testing was developed based on patented technology licensed from two world renowned medical centers, Mayo Clinic and Cincinnati Children’s Hospital Medical Center, who continue to be research collaborators. You may wish to research and find a company that best suits your needs.

The following image is an actual patient sample of test results obtained from GeneSight. This patient’s results show “Use as Directed” and normal genotype for the benzodiazepines and Z-drugs listed, yet they experienced severe tolerance withdrawal, adverse effects, interdose withdrawal, physical dependence and withdrawal upon cessation of the drugs.

Image credit: © Assurex Health, Inc. All Rights Reserved

The same patient did show moderate and significant gene-drug interactions for some of the SSRIs:

Pharmacogenomic testing, or similar, may be the future of medicine. If you are considering taking a benzodiazepine, or other psychotropic drugs, you may wish to have this testing done prior to doing so. It is certainly a useful tool to allow a patient and prescriber to make more-informed decisions about medications.