Does elderberry interact with risperidone (Risperdal), atomoxetine (Strattera), and guanfacine (Intuniv)?

Elderberry Interactions with Risperidone, Atomoxetine, and Guanfacine

Elderberry supplements should be avoided when taking risperidone, atomoxetine (Strattera), or guanfacine (Intuniv) due to potential drug interactions and limited evidence of benefit compared to risks.

Elderberry and Medication Interactions

General Concerns with Herbal Supplements

• Herbal supplements, including elderberry, are not regulated by the FDA with the same scrutiny as conventional medications, leading to potential safety concerns 1
• The Mayo Clinic Proceedings identifies herbal supplements as having "actual drug interaction concerns" and notes they add to medication burden with "poor to no evidence of pharmacological benefit" 1

Specific Concerns with Elderberry

• Elderberry has been shown to have weak inhibitory effects on cytochrome P450 (CYP) 3A4 enzyme pathways in vitro 2
• Risperidone is metabolized via the CYP2D6 and CYP3A4 pathways, creating potential for interaction with elderberry 3
• A recent case report documented significant adverse effects (including liver injury) when elderberry was used concurrently with pazopanib, another medication metabolized through CYP3A4 2

Medication-Specific Considerations

Risperidone (Risperdal)

• Risperidone is metabolized primarily through CYP2D6 and CYP3A4 enzyme pathways 3
• Drugs that inhibit CYP3A4 may alter risperidone plasma concentrations 3
• Risperidone has been associated with serotonin syndrome when combined with serotonergic agents 4
• Elderberry's potential inhibition of CYP3A4 could theoretically increase risperidone levels and side effects 2, 3

Atomoxetine (Strattera)

• Atomoxetine is primarily metabolized by CYP2D6 5
• While there are no direct studies on elderberry-atomoxetine interactions, the potential for herb-drug interactions exists given elderberry's effects on metabolic pathways 6
• Concurrent use of substances that affect hepatic enzyme systems should be approached with caution 6

Guanfacine (Intuniv)

• Limited specific data exists on interactions between elderberry and guanfacine
• As a general principle, herbal supplements should be used cautiously with prescription medications, especially in children and adolescents 1
• The American Geriatrics Society recommends avoiding herbal supplements in older adults due to medication burden and potential interactions 1

Clinical Recommendations

Risk Assessment

• The benefit-risk ratio for elderberry supplements is unfavorable when used with these medications 1
• While elderberry has shown some efficacy for cold and influenza in limited studies, these benefits don't outweigh potential interaction risks 1
• Patients taking multiple medications (polypharmacy) are at higher risk for adverse drug interactions 1

Alternative Approaches

• If immune support is desired, consider evidence-based approaches rather than elderberry supplements 1
• For patients insistent on using elderberry, recommend:
  • Temporal separation from medication administration (though this may not eliminate interaction risk) 6
  • Close monitoring for adverse effects including sedation, cognitive changes, or liver function abnormalities 2

Monitoring Parameters

• If a patient is already taking elderberry with these medications, monitor for:
  • Signs of increased medication effects or toxicity 3
  • Changes in liver function tests, particularly with risperidone 1, 2
  • Changes in blood pressure, especially with guanfacine 6

Special Populations

Children and Adolescents

• Extra caution is warranted in pediatric populations taking these medications 1
• Children may be more susceptible to adverse effects of medications and their interactions 1

Older Adults

• The American Geriatrics Society specifically recommends against herbal supplements in older adults due to medication burden and interaction potential 1
• Older adults are more susceptible to adverse drug effects and interactions 1