CYP2D6

Before prescribing your medication, your doctor would have carefully considered your biology including age, sex, weight, diet, and pre-existing conditions that could influence your response to a medication. The doctor would then prescribe a ‘normal’ dose. The problem with ‘normal’, ‘one size fits all’ dosing is that it doesn’t take into account how your body metabolises or processes (breaks down) your prescribed medication.

The rate of metabolism is important because it determines how your body processes your medication. Some people metabolize a drug so rapidly that the intended therapy may not work as expected; in others, metabolism may be so slow that ‘normal’ doses have toxic effects. Your rate of drug metabolism is directly influenced by your genes.

Your medication is processed (broken down) by drug-metabolizing enzymes that are coded by the CYP2D6 gene. Testing for variants of the CYP2D6 gene can therefore help determine if you are a fast drug metaboliser, normal drug metaboliser or slow drug metaboliser. Individuals who are fast metabolisers, metabolize a drug so rapidly that the intended therapy may not work as expected; in individuals who are slow metabolizers, metabolism may be so slow that ‘normal’ doses lead to toxic or adverse effects.

Knowing your metaboliser status can help your doctor understand if the ‘normal’ dose they had prescribed for you is actually safe and clinically effective for you. The doctor can use this information to personalise your dose or remove the medication altogether. This is a Personalised approach that enables the right drug and dosage to be prescribed based on your genetics.