ADHD Medication Side Effects
Attention deficit hyperactivity disorder (ADHD) affects approximately 11 percent of children and approximately 4 percent of adults in the United States. The disorder is caused by deficiency in brain chemicals that normally allow for transmission signals in nerve cells. The medications most commonly used to treat ADHD are stimulants that help the affected cells produce more of the deficient chemicals.
While some medications used to treat ADHD are non-stimulants, stimulants are the most common medicines used to treat ADHD because they increase the activity of deficient chemicals in the brain called neurotransmitters. Paradoxically, instead of increasing restlessness, the drugs balance deficient chemicals so that patients become calmer, according to research on ADHD by the National Institute of Mental Health. The most common stimulants used to treat ADHD are methylphenidate and dextroamphetamine; these are generic drugs marked under several brand names and are tested by the Rxight® genetic test.
Serious Side Effects
Serious and life-threatening side effects of ADHD medications include rapid heartbeat and heart rhythm irregularities. Stimulant ADHD medications increase heart rate and blood pressue, and serious adverse cardiovascular events such as heart attacks and sudden death as well as strokes can occur, according to Food and Drug Administration: “Communication about an Ongoing Safety Review of Stimulant Medications used in Children with Attention-Deficit/Hyperactivity Disorder” (December, 2011).
Risk of Addiction
The risk of addiction to most ADHD medications is very high, as these stimulant drugs tend to produce feelings of energy and sometimes euphoria in genetically susceptible individuals, and can even induce manic or psychotic episodes, according to the National Institute on Drug Abuse (January 2014)
Common Side Effects
Side effects are often experienced by patients taking ADHD medications. Adverse reactions occur for a number of reasons and vary according to the type of medication prescribed, the patient’s unique genetic makeup, as well as interactions with other medications that the patient is taking. Common and often bothersome side effects of stimulants include: loss of appetite, stomach upset, drowsiness, irritability, and trouble falling asleep.
The most common reason that patients discontinue ADHD medications is because of unpleasant adverse reactions, according to Current Psychiatry Reports: “Enhancing ADHD Medication Adherence: Challenges and Opportunities” (July 2013). By stopping medicines, patients lose the therapeutic benefit and may experience decreased quality of life, according to the article. Meanwhile, other patients may not derive benefit from ADHD medications at standard doses due to their genetics. When patients are confident that side effects may be minimized, adherence to medication regimens increases.
Understand Your Risks with the Rxight® Genetic Test
Rxight® DNA testing is based on the analysis of gene variants that affect how ADHD drugs and hundreds of other prescription and over-the-counter medications work. The testing is done by taking a DNA sample from a cheek swab and sending it for processing, where significant genes and their alleles are tested across over 40 pharmacological classes, including ADHD medications. Each patient receives a Personalized Medication Review® interpreted by a pharmacist trained in pharmacogenetics. ADHD medications in the Rxight® medication panel include: amphetamine (Adderall), dexmethylphenidate (Focalin), several brands of dextroamphetamine (Dexedrine, Dextrostat, ProCentra), lisdexamfetamine (Vyvanse) and several brands of methylphenidate (Concerta, Ritalin, Quillivant).
How Does Pharmacogenetic Testing Work?
Pharmacogenetics is the study of the way genetic variants affect drug metabolism. You experience side effects in part because of genetic variants that affect how the medicine is assimilated. “Poor metabolizers” of ADHD medications may experience more adverse reactions because the medication accumulates in the body. “Rapid metabolizers” eliminate the drug too quickly and do not derive therapeutic value. Prescribers often use a “trial and error” method to find dosages that reduce symptoms and minimize unpleasant side effects or serious adverse reactions. In contrast, pharmacogenetic testing helps clinicians select medications and doses associated with better therapeutic value and fewer side effects – rather than relying on a potentially protracted and deleterious trial and error approach.
Contributors to this Article:
Michael Sapko, MD, PhD; Deborah Kallick, PhD, Medicinal Chemistry