Clinical Update
May 2020
Review of New InterAct Rx Analyte Positivity
In 2015, Aegis Sciences Corporation began to seek out a way to expand the clinical information that could be provided through definitive testing. With this in mind and an understanding of the limitations of current medication reconciliation practices, we developed an objective test (InterACT RxTM) to help identify potential drug-drug interactions (DDIs) in patients who may be prone to adverse drug events (ADEs). The initial goal of this product was to provide clinicians with a tool to identify ingested prescription medications and non-prescription substances, and subsequent potential interactions or ADEs capable of impacting commonly prescribed medications used to treat chronic pain and mental health disorders.
In April, InterACT Rx testing was expanded to assist with the identification of additional commonly prescribed interacting medications used to treat comorbidities that pain and behavioral health patients may face. A high-level summary of the expansion, which moves the total number of tested substances to over 180 analytes, can be seen in the table below:
|
Drug Classes Added |
Drug Classes Expanded |
|
Anti-Parkinson Agents |
Antidepressants and Antipsychotics |
|
Antithrombotics |
Antiemetics and Gastric Reflux |
|
Cognitive Enhancement Agents |
Antihypertensives |
|
Inhaled Corticosteroids and Beta Agonists |
Antimicrobials and Antiretrovirals |
|
Chemotherapeutic Agents |
We have completed an initial review of samples received since the update and are now reporting the most frequently detected analytes. The top 10 analytes detected in the enhanced InterACT Rx test are as follows:
|
Analyte |
Prevalence |
New Analyte? |
|
Omeprazole/Esomeprazole |
14% |
Yes |
|
Amlodipine |
12% |
No |
|
Atorvastatin |
11% |
No |
|
Metoprolol |
9% |
Yes |
|
Cyclobenzaprine |
9% |
Yes |
|
Albuterol |
7% |
Yes |
|
Azithromycin |
6% |
Yes |
|
Citalopram/Escitalopram |
6% |
No |
|
Duloxetine |
6% |
No |
|
Trazodone |
6% |
Yes |
The majority of the top 10 detected analytes are new offerings, which reinforces our commitment to review the analyte list to look for enhancement opportunities. This is necessary because, in some cases, our drug information source, First Databank®, includes new interactions as the scientific literature is expanded. In other instances, Aegis will offer a new pain or behavioral health compliance drug(s) which may be prone to new DDIs. Since our latest enhancement, the most observed severe interactions observed from the six new medications from the table above are as follows:
|
Analyte Pair |
MedKnowledge® Interaction Description |
Interaction Severity |
|
Paroxetine, Trazodone |
Concurrent administration of fluoxetine or paroxetine with selected cyclic agents which are metabolized by CYP2D6 or CYP2C19 may result in an increase in serum levels, toxicities (e.g. risk for seizures, severe anticholinergic effect), and/or clinical effects of the tricyclic agent or trazodone. Clomipramine, desipramine, imipramine, nortriptyline, and trimipramine are classified by CredibleMeds(3) as possible QT prolonging agents. Increased serum levels of these tricyclic agents may increase the risk for torsades de pointes. Concurrent administration of fluoxetine or paroxetine with clomipramine, and perhaps with imipramine or high dose amitriptyline may increase the risk for serotonin syndrome. Cyclic antidepressants included in this monograph are amitriptyline (> 40 mg), clomipramine (> 25 mg), desipramine (all strengths), doxepin (> 25 mg), imipramine (> 10 mg), nortriptyline (> 30 mg), trazodone (> 75 mg), and trimipramine (> 25 mg). |
Severe |
|
Fluoxetine, Trazodone |
Concurrent administration of fluoxetine or paroxetine with selected cyclic agents which are metabolized by CYP2D6 or CYP2C19 may result in an increase in serum levels, toxicities (e.g. risk for seizures, severe anticholinergic effect), and/or clinical effects of the tricyclic agent or trazodone. Clomipramine, desipramine, imipramine, nortriptyline, and trimipramine are classified by CredibleMeds(3) as possible QT prolonging agents. Increased serum levels of these tricyclic agents may increase the risk for torsades de pointes. Concurrent administration of fluoxetine or paroxetine with clomipramine, and perhaps with imipramine or high dose amitriptyline may increase the risk for serotonin syndrome. Cyclic antidepressants included in this monograph are amitriptyline (> 40 mg), clomipramine (> 25 mg), desipramine (all strengths), doxepin (> 25 mg), imipramine (> 10 mg), nortriptyline (> 30 mg), trazodone (> 75 mg), and trimipramine (> 25 mg). |
Severe |
|
Azithromycin, Fluconazole |
The concurrent use of azithromycin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) |
Severe |
|
Azithromycin, Hydroxyzine |
The concurrent use of hydroxyzine with agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes.(1-4) |
Severe |
|
Azithromycin, Levofloxacin |
The concurrent use of azithromycin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) |
Severe |
|
Azithromycin, Citalopram / Escitalopram |
The concurrent use of azithromycin with other agents that prolong the QTc interval may result in potentially life-threatening cardiac arrhythmias, including torsades de pointes(TdP).(1) |
Severe |
|
Cyclobenzaprine, Tramadol |
Concurrent use of tramadol and a tricyclic compound may result in seizures(1) or serotonin syndrome(2) and may increase the risk of suicide.(1) Concurrent use of tramadol and carbamazepine may significantly reduce the analgesic effect of tramadol.(1) Concurrent use of tapentadol and a tricyclic compound may result in serotonin syndrome.(2) Although not used therapeutically as antidepressants, carbamazepine and cyclobenzaprine are tricyclic compounds. |
Severe |
|
Citalopram/Escitalopram, Esomeprazole/Omeprazole |
Concurrent use of an agent that inhibits CYP2C19 may result in elevated levels of and toxicity from citalopram, including prolongation of the QTc interval. Prolongation of the QT interval may result in life-threatening arrhythmias, including torsades de pointes.(1,2) |
Severe |
|
Clopidogrel, Esomeprazole / Omeprazole |
Concurrent use of esomeprazole, omeprazole, or cimetidine may result in decreased clopidogrel effectiveness, resulting in increased risk of adverse cardiac events. |
Severe |
InterACT Rx can play a crucial role in medication management strategy by providing clinicians with objective, clinically actionable information to avoid potential DDIs and improve care.
NOTICE: The information above is intended as a resource for health care providers. Providers should use their independent medical judgment based on the clinical needs of the patient when making determinations of who to test, what medications to test, testing frequency, and the type of testing to conduct.