Personalised prescribing, guided by your biology.

Poor Metaboliser

The enzyme works very slowly, so medication can build up in the body. This increases the risk of side effects and adverse reactions, even at standard doses.

• Medication levels in the bloodstream may be higher than expected
• Standard doses may feel too strong or cause unwanted effects
• Dose reduction or alternative medication may be recommended
• More frequent monitoring may be advisable

What This Means in Practice

If you are a poor metaboliser and are prescribed a medication affected by your genotype, your clinician will consider:

• Starting at a lower than standard dose
• Slower dose titration schedule
• More regular therapeutic monitoring
• Alternative medications where a strong recommendation exists (e.g. allopurinol in HLA-B*58:01 carriers)

Intermediate Metaboliser

You break down certain medications somewhat more slowly than average. This is a very common finding and often results in moderate caution rather than major prescribing changes.

• Drug levels may run slightly higher than typical
• May benefit from slower dose titration
• Some medications may warrant a lower maintenance dose
• Often manageable with standard clinical monitoring

Clinical Example

For escitalopram in a CYP2C19 intermediate metaboliser, CPIC recommends starting with the standard dose but considering a slower titration and lower maintenance dose compared to a normal metaboliser. This is a "use thoughtfully" result — not a "do not use" result.

Normal Metaboliser

Your enzyme processes certain medications at the expected rate. Standard prescribing guidelines apply in most cases.

• Standard doses are likely to produce expected drug levels
• No major gene-related prescribing adjustments required
• Routine clinical monitoring applies
• Report may still show multi-gene interactions for some medications

Important Note

A normal metaboliser result for one gene does not mean there are no relevant pharmacogenomic findings in your report. Other genes (e.g. CYP2C19, HLA-B) may still have actionable results for different medications.

Always review your full PGx report alongside your clinician, not just a single gene result.

Rapid Metaboliser

You break down certain medications faster than average. This means standard doses may leave you with lower-than-expected drug levels, potentially reducing effectiveness.

• Medication may clear the body faster than typical
• Standard doses may provide less benefit
• May require higher doses or more frequent dosing for some medications
• Some medications may be less suitable than alternatives

What This Means in Practice

Rapid metabolism doesn't mean a medication won't work; it means achieving a therapeutic level may require dose adjustment. Your clinician will weigh this against safety and clinical context.

Ultrarapid Metaboliser

Your enzyme breaks down certain medications extremely quickly. This can make some medications less effective at standard doses, or in rare cases, create safety concerns when metabolites are active.

• Very fast clearance, medication levels may be very low
• Some medications may be unlikely to reach therapeutic range
• Alternative medications may be preferred
• Relevant for prodrugs where active metabolite levels may be unexpectedly high