Is detrol affected by genetics?

Yes — the active ingredient is metabolized by a gene known to vary between individuals.

Relevant genes: CYP2D6

detrol is affected by pharmacogenetics through the CYP2D6 gene. Your genotype for this gene can change how your body processes detrol, which can affect both how well it works and how well you tolerate it. The strongest evidence level on this page is Moderate, based on CPIC or FDA guidelines.

What's in detrol

tolterodine affected by CYP2D6

Affected by CYP2D6 · FDA · Moderate evidence

Read the full tolterodine genetics guide →

Tolterodine phenotype recommendations

Published guidance from FDA on how tolterodine should be dosed or substituted based on your CYP2D6 phenotype.

Phenotype	What it means	Recommendation	Evidence
Ultrarapid Metabolizer CYP2D6	Your body processes tolterodine at a normal rate. The standard dose should work as expected.	FDA Initiate therapy with recommended starting dose.	—
Normal Metabolizer CYP2D6	Your body processes tolterodine at a normal rate. The standard dose should work as expected.	FDA Initiate therapy with recommended starting dose.	—
Intermediate Metabolizer CYP2D6	Your body processes tolterodine at a normal rate. The standard dose should work as expected.	FDA Initiate therapy with recommended starting dose.	—
Poor Metabolizer CYP2D6	Your body breaks down tolterodine more slowly than normal, causing it to build up in your system. This increases the risk of side effects, including heart rhythm problems.	FDA Use with caution due to risk of QT prolongation. Consider dose reduction or enhanced cardiac monitoring.	Moderate
Indeterminate CYP2D6	The impact of your genotype on response to this drug is unknown	FDA Initiate therapy with recommended starting dose.	—
Not available CYP2D6	The impact of your genotype on response to this drug is unknown	FDA Initiate therapy with recommended starting dose.	—

Source: FDA

The gene behind the guidance

CYP2D6 Cytochrome P450 2D6

CYP2D6 is the most clinically important pharmacogene. It metabolizes around a quarter of all prescription drugs, including many antidepressants, opioids, and stimulants. The gene is unusually variable: roughly 7 percent of people are poor metabolizers (they barely activate CYP2D6), and another 1 to 3 percent are ultrarapid metabolizers (their enzyme is overactive).

For most CYP2D6 drugs, poor metabolizers feel stronger effects and more side effects at standard doses, while ultrarapid metabolizers may feel almost nothing. For prodrugs like codeine, the relationship flips: poor metabolizers feel less effect because they can't activate the drug.

See all drugs affected by CYP2D6 →

Related medications

Find out how your genetics affect detrol

This page describes the general pharmacogenetics. A Gene2Rx report analyzes your own DNA to tell you which metabolizer group you fall into, across every medication.

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Informational only — not medical advice. Pharmacogenetic guidance describes population-level patterns; your individual response depends on many factors. Never start, stop, or change a medication without talking to your prescribing clinician.