Amitriptyline (Elavil) and CYP2C19/CYP2D6 Pharmacogenomics
Last updated: August 2026
What Is Amitriptyline?
Amitriptyline (brand name Elavil) is a tricyclic antidepressant (TCA) prescribed for major depressive disorder, neuropathic pain, migraine prevention, fibromyalgia, and insomnia. While newer antidepressants (SSRIs, SNRIs) are more commonly used as first-line depression treatments, amitriptyline remains one of the most prescribed TCAs worldwide.
What makes amitriptyline uniquely relevant to pharmacogenomics is that it involves two pharmacogenes: CYP2C19 and CYP2D6. Both enzymes contribute to amitriptyline metabolism through different pathways, and CPIC provides dosing recommendations that consider both gene results together.
How CYP2C19 and CYP2D6 Affect Amitriptyline Metabolism
Amitriptyline metabolism follows two sequential pathways:
- N-demethylation (CYP2C19): CYP2C19 converts amitriptyline to nortriptyline, an active metabolite that is itself a marketed antidepressant.
- Hydroxylation (CYP2D6): CYP2D6 converts both amitriptyline and nortriptyline to hydroxylated metabolites, which are the primary clearance pathway.
This dual-gene involvement means both your CYP2C19 results and CYP2D6 metabolizer status affect amitriptyline pharmacokinetics. CYP2C19 determines how quickly amitriptyline is converted to nortriptyline, while CYP2D6 determines how quickly both compounds are cleared. The combination can significantly alter drug exposure profiles.
Learn more about how pharmacogenomic testing works from raw DNA data, or read about metabolizer status in plain language.
Have 23andMe or AncestryDNA raw data? Find out if amitriptyline is flagged for your CYP2C19 genotype — the half of the picture DecodeMyBio can call from array data (see why CYP2D6 is different below).
CPIC Guideline Summary
The amitriptyline–CYP2C19/CYP2D6 interaction has a CPIC Level A classification — the strongest evidence level. The CPIC guideline for tricyclic antidepressants (Hicks et al., 2017; PMID: 27997040) provides recommendations based on both genes:
- CYP2D6 NM + CYP2C19 NM: Standard dosing applies.
- CYP2D6 PM: Consider a 25% dose reduction of the recommended starting dose and monitor plasma concentrations. Alternatively, consider an alternative drug not predominantly metabolized by CYP2D6.
- CYP2D6 UM: Avoid amitriptyline due to potential for subtherapeutic levels. Consider an alternative drug not metabolized by CYP2D6.
- CYP2C19 UM: Consider a 25% dose reduction if CYP2D6 status is also normal. Increased conversion to nortriptyline may alter the amitriptyline-to-nortriptyline ratio.
- CYP2C19 PM: Consider an alternative drug if CYP2D6 status is also non-normal. Reduced conversion to nortriptyline leads to higher amitriptyline accumulation.
All dose adjustments are prescriber decisions. The dual-gene nature of amitriptyline metabolism makes the prescriber's assessment of both results especially important.
Amitriptyline vs. SSRIs: Pharmacogenomic Complexity
Most SSRIs involve primarily one pharmacogene — escitalopram and sertraline are CYP2C19-dependent, while paroxetine is CYP2D6-dependent. Amitriptyline is more pharmacogenomically complex because both genes contribute to its metabolism through different pathways.
DecodeMyBio calls CYP2C19 from your raw data, so your medication results can give you that half of the CPIC picture for amitriptyline. DecodeMyBio does not call CYP2D6, so the CYP2D6 half of the recommendation — which CPIC weighs together with CYP2C19 for this specific drug — can't come from your file alone. See why CYP2D6 is different.
Already have your DNA file? Check your CYP2C19 status for amitriptyline, and see why DecodeMyBio can't call the CYP2D6 half of the picture from it.
Learn how to upload your data · About Your Psychiatric Medication Results
Understanding Your Results
If you have raw DNA data from 23andMe, AncestryDNA, or another consumer service, DecodeMyBio can analyze your CYP2C19 status and give you that half of the CPIC picture for amitriptyline. DecodeMyBio does not call CYP2D6: gene deletions, duplications, and hybrid alleles that drive CYP2D6 phenotype need a specialized caller a consumer genotyping array does not provide, and we will not invent a result we can't support. Your medication results will include your CYP2C19 result and will tell you plainly that the CYP2D6 half of amitriptyline's CPIC recommendation isn't something we can determine from your file.
Because amitriptyline's CPIC guidance weighs CYP2C19 and CYP2D6 together, getting the full picture — including the CYP2D6 half — requires clinical-grade testing with copy-number analysis; ask your prescriber about it. Amitriptyline response also depends on factors beyond CYP2C19/CYP2D6 status, including age, weight, other medications, liver function, and clinical indication. See our methodology for how results are derived and our limitations page for important caveats.
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Frequently Asked Questions
Why do both CYP2C19 and CYP2D6 matter for amitriptyline?
CYP2C19 converts amitriptyline to nortriptyline, while CYP2D6 clears both compounds. Your status for both genes determines the overall drug exposure profile.
What does CPIC recommend for amitriptyline?
CPIC recommends dose adjustments or alternative drugs depending on both CYP2C19 and CYP2D6 status. CYP2D6 poor metabolizers may need a 25% dose reduction. CYP2D6 ultrarapid metabolizers should consider an alternative drug.
Is amitriptyline still commonly prescribed?
Yes. While SSRIs are more common for depression, amitriptyline remains widely used for neuropathic pain, migraine prevention, fibromyalgia, and treatment-resistant depression.
How is amitriptyline different from SSRIs for pharmacogenomics?
SSRIs typically involve one primary gene. Amitriptyline involves both CYP2C19 and CYP2D6, making the pharmacogenomic evaluation more complex and the combined result more clinically meaningful.
Can 23andMe raw data show my status for both genes?
Only partially. DecodeMyBio analyzes CYP2C19 from consumer raw data. CYP2D6 gene deletions, duplications, and hybrid alleles cannot be detected from array data, so DecodeMyBio does not call a CYP2D6 result — the CYP2D6 half of amitriptyline's guidance needs clinical-grade testing.
Does amitriptyline pharmacogenomics predict if the drug will work for my condition?
No. Pharmacogenomics shows how your body metabolizes amitriptyline — not whether it will be effective. Treatment response depends on many factors beyond drug metabolism.
Last reviewed: August 2026 · Vytautas Jazbutis