Key takeaways
Atomoxetine can prolong the QT interval during our heart’s rhythm cycle, creating a risk for dangerous heart rhythms. This risk is substantially higher when combined with other QT-prolonging meds.
Metabolism of atomoxetine involves the liver’s CYP2D6 enzyme, and when the drug is taken along with drugs that inhibit this enzyme, atomoxetine levels can be too high and cause adverse effects.
Monoamine oxidase inhibitors (MAOIs) can exacerbate the CNS side effects of atomoxetine, making that group of medications a contraindication to taking atomoxetine.
Individuals who are very sensitive to elevated blood pressure or acute glaucoma should not take atomoxetine due to the potential for worsening the condition.
Taking atomoxetine in the setting of bipolar disorder could precipitate mania.
Atomoxetine is the generic version of the brand name Strattera. This drug stands out as one of the few non-stimulant options for the treatment of adults and children with attention-deficit hyperactivity disorder (ADHD) that are approved by the U.S. Food and Drug Administration (FDA). As an ADHD treatment that avoids many of the side effects and addiction potential of central nervous system (CNS) stimulants like Ritalin and Adderall, atomoxetine has an important role. It is not a perfect choice, however, but no prescription drug is. The key is to know how to reduce the risk of taking a medicine. In the case of Strattera, that means understanding what drug and health conditions it can interact with negatively. Take a few moments to learn these characteristics.
Atomoxetine drug interactions
Understanding the types of interactions and knowing some of the drugs involved are crucial for staying safe during the treatment of attention deficit hyperactivity disorder with Strattera.
QT-prolonging drugs
QT prolongation amounts to slowing the electrical reset after heartbeats. Although it is not among its common side effects, atomoxetine can cause this delay, and as a result, there is more risk of life-threatening heart arrhythmia called torsades de pointes that can lead to sudden death. Many different medications can prolong the QT interval, and in the setting of atomoxetine therapy, this adverse reaction could be additive and warrants immediate medical attention. Drugs with QT-prolonging potential include the following medicines:
- Zithromax (azithromycin)
- Clarithromycin
- Levofloxacin
- Moxifloxacin
- Seroquel (quetiapine)
- Risperdal (risperidone)
- Abilify (aripiprazole)
- Zyprexa (olanzapine)
- Remeron (mirtazapine)
- Silenor (doxepin)
The entire list of medications that can prolong the QT interval is much longer. You might note that many of the drugs come from the macrolide antibiotic, quinolone antibiotic, antipsychotic, and antidepressant categories. The antidepressants are most concerning because depression and ADHD often coexist. Taking atomoxetine with one of these antidepressants could lead to QT prolongation.
If your medication list contains medications that can prolong the QT interval, ask your medical provider for medical advice and see if an electrocardiogram (EKG) should be done. An EKG is a simple, non-invasive test measuring the QT interval and looking for an irregular heartbeat.
CYP2D6 inhibitors
The CYP2D6 liver enzyme metabolizes atomoxetine as part of the body’s elimination process. Inhibiting the enzyme leads to an abundance of the drug, possibly resulting in serious side effects, including suicidal ideation (suicidal thoughts), hypertension, tachycardia (fast heartbeat), panic attacks, aggressive behavior, and psychosis.
Certain antidepressants are some of the biggest names among CYP2D6 inhibitors. These include:
- Prozac (fluoxetine)
- Paxil (paroxetine)
- Wellbutrin XL (bupropion extended-release)
- Cymbalta (duloxetine)
Once again, having both ADHD and depression is not uncommon, so these drug interactions with the use of atomoxetine must be pointed out. If you are on both, call your doctor or pharmacist’s attention to it and get medical help with deciding what to do.
Monoamine oxidase inhibitors
MAO inhibitors interact with numerous medications and can precipitate serious problems. Although many can function as antidepressants, they are not used much for this indication. Some members of the drug class, namely Azilect and selegiline, are used for Parkinson’s disease, and another, Zyvox, is an antibiotic.
MAOIs can lead to an increase in adrenaline. Since atomoxetine treats attention-deficit hyperactivity disorder by being a selective norepinephrine reuptake inhibitor and since norepinephrine is an adrenaline compound, MAOIs are hazardous if taken concurrently or within 14 days of atomoxetine. Too much norepinephrine effect in the CNS can lead to tremor, rigidity, fever, confusion, and seizures. MAOIs should be avoided with atomoxetine, and examples include:
- Zyvox (linezolid)
- Methylene Blue
- Nardil (phenelzine)
- Azilect (rasagiline)
- Selegiline
- Parnate (tranylcypromine)
Atomoxetine food interactions
There’s no need to be concerned about atomoxetine and food interactions. You may take one daily dose on an empty stomach or with meals.
Other atomoxetine interactions
Besides drug interactions, atomoxetine can have more adverse effects when taken in the setting of certain medical conditions. Being aware of these interactions is every bit as important.
Atomoxetine and severe cardiovascular disease
Strattera can cause elevated heart rate and high blood pressure, two things our hearts and blood vessels do not like. If you have severe cardiovascular disease, such as coronary artery disease or peripheral vascular disease, these physiologic changes could be more detrimental, even leading to heart attack. Because of this, it is best to avoid atomoxetine when there are significant cardiac issues or vascular disease.
Atomoxetine and narrow-angle glaucoma
Narrow-angle glaucoma is an uncommon variant of glaucoma in which sudden increases in eye pressure can occur. Medications are one of the potential triggers for people with narrow-angle glaucoma. Since atomoxetine is on the list of triggers, you should avoid it if you have this rare condition.
Atomoxetine and bipolar disorder
Manic episodes and depressive episodes characterize typical bipolar disorder episodes. Mania can be pretty dangerous when it involves agitation and delusions. Based on Strattera’s mechanism of boosting norepinephrine action in the CNS, there is reason to worry that the drug could instigate a manic episode in someone with bipolar disorder. This concern is worth talking to your healthcare provider about before taking atomoxetine if you have bipolar disorder.
Atomoxetine and liver disease
If your liver function is impaired, the body may not metabolize atomoxetine as readily. To prevent excessive levels and action of the drug, you may need a lower dose in the setting of significant liver disease, or you may want to look for alternatives.
Atomoxetine and prostatic hypertrophy
On their own, an enlarged prostate and atomoxetine can cause urinary retention, a condition in which the bladder does not fully drain. Taking the drug in the setting of prostatic hypertrophy could lead to a bigger issue with emptying your bladder. If you have prostate problems, double-check with the prescribing healthcare professional before taking Strattera.
How to minimize atomoxetine interactions
These are all identifiable and predictable interactions between atomoxetine and other drugs or health conditions. It takes all possible eyes to watch out for them, though. That means that patients need to take an active role in this surveillance. Check for drug interactions among your list of prescription medicines, over-the-counter (OTC) drugs, herbal products, and supplements. Maintain a list of your meds to make this easier. Do the same for your medical problems.
Most importantly, actively discuss whether a medicine is right for you. That means considering drug costs, too. A SingleCare discount card could make those decisions easier if pharmacy prices are a concern.
When to talk to a healthcare provider about atomoxetine
To find possible interactions between atomoxetine and other health issues, ask your pharmacist and medical professional to check your medication list. Doing so means you are engaged in your care. You should ask these questions when you are first prescribed the medication, periodically throughout treatment, and when any prescription or nonprescription drugs are about to be added on.
Sources
- Strattera label, FDA (2003)
- Atomoxetine: Drug label, NIH DailyMed (2021)
- Electrocardiogram (EKG), Mayo Clinic (2022)
- Clinically relevant drug interactions with monoamine oxidase inhibitors, Health Psychology Research (2022)