Is Zyloprim affected by genetics?

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

Relevant genes: ABCG2

Zyloprim is affected by pharmacogenetics through the ABCG2 gene. Your genotype for this gene can change how your body processes Zyloprim, 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 Zyloprim

allopurinol affected by ABCG2

Affected by ABCG2 · DPWG · Moderate evidence

Read the full allopurinol genetics guide →

Allopurinol phenotype recommendations

Published guidance from DPWG on how allopurinol should be dosed or substituted based on your ABCG2 phenotype.

Phenotype	What it means	Recommendation	Evidence
Normal Function ABCG2	Your ABCG2 genotype does not change how you respond to allopurinol; standard dosing applies.	DPWG Use standard allopurinol dosing.	Moderate
Decreased Function ABCG2	Your genotype suggests allopurinol is somewhat less effective at lowering uric acid. A modestly higher dose is typically required.	DPWG Use 1.25 times the standard allopurinol dose. Equivalent titration schedule: 100, 200, 400, 500 mg/day instead of the usual 100, 200, 300, 400 mg/day.	Moderate
Poor Function ABCG2	Your genotype suggests allopurinol is notably less effective at lowering uric acid. A higher dose is typically required to achieve the target level.	DPWG Use 1.4 times the standard allopurinol dose. Equivalent titration schedule: 100, 300, 400, 600, 700 mg/day instead of the usual 100, 200, 300, 400, 500 mg/day.	Moderate
Indeterminate ABCG2	We were not able to determine your ABCG2 genotype, so we cannot personalize guidance for allopurinol.	DPWG Use standard allopurinol dosing and titrate to target uric acid concentration.	—
Not available ABCG2	We do not have an ABCG2 result for you, so we cannot personalize guidance for allopurinol.	DPWG Use standard allopurinol dosing and titrate to target uric acid concentration.	—

Source: DPWG

The gene behind the guidance

ABCG2 ATP-Binding Cassette Subfamily G Member 2 (BCRP)

ABCG2 is a transporter that moves urate and several drugs out of cells. The Q141K variant (rs2231142) is common, particularly in East Asian populations, and reduces transporter function. Carriers have higher baseline serum urate and a smaller response to allopurinol, so they often need higher doses or a switch to a different urate-lowering drug. ABCG2 also affects how quickly the body clears rosuvastatin.

Q141K carriers often need higher allopurinol doses to reach the under-6 mg/dL urate target, or a switch to febuxostat.

See all drugs affected by ABCG2 →

Browse the full drug-class: Gout treatment.

Find out how your genetics affect Zyloprim

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.