What is CYP2D6?
CYP2D6 is a crucial enzyme in the liver responsible for the breakdown and activation of approximately 25% of all medications prescribed worldwide. Unlike biomarkers like GGT, which can fluctuate, your CYP2D6 status is genetically determined and unchangeable.
The gene determines whether you metabolize medications “normally,” or whether this process is far too slow or too fast. This directly impacts the effectiveness of your treatment and the risk of side effects.
Why test your CYP2D6 status?
When the CYP2D6 enzyme activity is abnormal, the standard dosage of a medication may be unsafe or ineffective for you:
- Side effects: If the medication is broken down too slowly, it accumulates in your blood, which can lead to serious side effects, even at a “normal” dose.
- No effect: If the medication is broken down too quickly, it is removed from your body before it can do its job.
- Inactive medication: Some medications (such as codeine) require activation by CYP2D6. If the enzyme isn’t working, you won’t experience any pain relief.
Medicines in which CYP2D6 plays a role
The following groups of medications are primarily metabolized by the CYP2D6 enzyme. An Easly pharmacogenetic passport is very valuable for these medications:
- Antidepressants: e.g., Amitriptyline, Venlafaxine, Paroxetine, Fluoxetine.
- Beta-blockers: e.g., Metoprolol, Bisoprolol.
- Painkillers: e.g., Tramadol, Codeine.
- Antipsychotics: e.g., Haloperidol, Risperidone.
Oncology: Tamoxifen.
Interpretation of your CYP2D6 status
Your genetic test results are classified into four metabolism types. This determines how your body responds to the medications mentioned above:
| Result | Interpretation | Impact on Medication |
|---|---|---|
| PM | Poor Metabolizer | The enzyme doesn't work. High risk of side effects or no effect with prodrugs (such as codeine). |
| IM | Intermediate Metabolizer | The enzyme works slowly. Increased risk of side effects; a lower dosage is often desirable. |
| NM | Normal Metabolizer | The enzyme is functioning normally. The standard dosage is usually appropriate for your body. |
| UM | Ultrarapid Metabolizer | The enzyme works extremely quickly. Medication is broken down too quickly; standard doses are often ineffective. |
Medical interpretation & advice
The results of your test at Easly are checked against the official KNMP medication guidelines (G-Standard). This provides you, your pharmacist, and your doctor with a scientific foundation for personalized treatment.
Important: Always use this result in consultation with your doctor or pharmacist. Never adjust your dosage independently. A doctor or pharmacist may decide to optimize your dosage or switch to a medication that is not dependent on this specific enzyme based on your profile.
Don’t suffer through unexplained side effects.
Want to know if your symptoms can be explained by your DNA profile? Take the free Pharmacogenetic Quick Scan and get immediate confirmation of whether testing is beneficial for you.
