Demo: Medication Response: Examples

Genes play a role in how a person responds to certain medications. Here are a few examples of medication response results:

• Anesthetics 

  Anesthetics are medications that cause a temporary loss of sensation. They usually are used during a surgical operation to prevent the patient from feeling pain.

  Malignant hyperthermia (MH) is a rare genetic condition that occurs when a person with a specific gene change is given anesthesia medications (anesthetics). Symptoms include increased body temperature, increased heart rate and breathing rate, and rigid muscles. The symptoms of MH can be life threatening if not treated immediately.

  Who is at risk?

  About 1 in 3,000 people are at risk for MH. These people do not have any health problems until they are exposed to certain anesthetics.

  Benefits of knowing your gene status

  Variations in a gene called RYR1 put people at risk for MH. If you know that you have a change in your RYR1 gene, you can tell your doctor this information before you have any anesthesia. That way, your doctor can make sure to choose an anesthesia medication that does not trigger malignant hyperthermia.

• Blood thinners 

  A blood thinner is a medication that stops a patient’s blood from clotting (coagulating) too much. It can also prevent blood clots from getting bigger. Blood thinners are also called anticoagulants. The blood-thinning medication warfarin is known by brand names Coumadin, Jantoven, Marevan, Lawarin, Waran, and Warfant.

  Blood thinners are prescribed to people who are:

  • At risk for developing blood clots.
  • Have prosthetic (replacement) heart valves.
  • Recovering from a heart attack, stroke, or a blockage in the lung’s main artery (called a pulmonary embolism).

  Who is at risk?

  Problems with blood thinners are more common among people of European descent compared to people of African or Asian descent.

  Benefits of knowing your gene status

  Mutations in a gene called CYP2C9 interfere with the body’s ability to break down the blood thinner warfarin. This means that the medication stays in the blood system longer than normal and thus may cause life-threatening internal bleeding.

  If you ever need anticoagulant therapy, genetic information may help healthcare professionals select the most appropriate warfarin dose.

• Chemotherapy 

  Chemotherapy is a treatment for cancer using medications to kill certain cells in the body. Medications called 6-mercaptopurine and azathiopurine (also known by the brand name Azasan) are two examples. A side effect of these medications can be bone marrow suppression, which can be life threatening.

  Who is at risk?

  Chemotherapy medications may be given to people who have cancer, autoimmune disorders, or recently had organ transplants.

  Benefits of knowing your gene status

  Some people have changes in a gene called TPMT that make it difficult for their bodies to process these medications. As a result, they are at a particularly high risk for bone marrow suppression while on these chemotherapy medications.

  If you know you have a TPMT gene change, you can share this information with your healthcare provider. That way, the medical team will have information to help decide which medications are best if you:

  • Need medical treatments for cancer or autoimmune disorders.
  • Require an organ transplant.